I'm sure everyone is saying it, but cold vs warm test is definitely required to see true test between cells at different temps! Thanks for the videos! I can't tell you how much I've learned from you and this channel! Thanks Andy!
nominal capacity is on 20C, on lower temps can be different, and o low temp need to lower currents. I have 176Ah lifepo from Aliexpress gradeA, 3 years run on solar system, 700 100% cycles calculate by charged/discharged energy and by victron smartshunt i charge it to full, sync SOC to 100% and discharge to 2.5v per cell and discharge 170Ah.. its really good result. My 300Ah cell is too young for any wearing test.
What about taking cell 6 and the tester into the house, let them warm up to room temperature and repeat the test, that should show if temperature is a contributing factor.
I could be incorrect but charging/discharging at 40a does 'warm up' the cell. True in freezing temperatures operating the battery may be a problem. Maybe Andy could retest with the cell in a heated 'box for a test. I personally found the battery performs well at 80f.
@@krg038 That is correct. The temperature I measured and showed in the video was of one of the cells on the workbench, not one I have tested. They are actually getting a bit warm during this test with 40A. I've got three cells inside the house now and will test them again with the original tester (20amps) so we can compare better.
@@OffGridGarageAustralia IIRC lead acid batterys have 2 or 3 quotes on AMP HOURS. 10 hour, 20 hour and 100 hour. As LiPos the same? Do they provide more amphours if drained slower?
Instead of just randomly speculating, let's do some math. For one, the EVE datasheet states to expect a cycle life of >=2500 without fixture ('compression', yes, I know...) and >=3500 with. So we already increase our normal degradation by 28% by not having the cells in a fixture. Secondly, find some temperature discharge curves for LiFePO4 for example from Nordkyn et al. You should expect at least a drop of 2% at your current temperatures. Finally, a couple percent calendar aging. This also depends on temperature: the higher the temperature your batteries sit at, the faster the degradation - since you're in sunny hot Australia.... The literature has several models on this, but there are numerous variables I can't account for, but a couple percent is not out of the ordinary over the 4 year life since manufacturing. Based on all of this, 5%, or even 8%, doesn't sound bad at all. It would be good to do a capacity test again at 25C to at least remove that variable...
Wait! Firstly, this cycle increase they promise with fixture is only valid for 1C charge and discharge cycle (or 0.5C with other cells like the 280Ks) as per their test conditions. So unless you do that in your daily usage, you cannot compare it to what is on the data sheet. We know, lower current is causing less degradation. Also, all these specs form the data sheet are only valid for certified cells, not to rejected cells, I believe. (except the voltage, current and temperature values of course, they still apply). Secondly, even we're in 'sunny hot Australia' it does not mean these batteries are actually getting that hot as many would expect. Most of the time, they are at around 20-25° while they may get 'hot' as 38°C in summer for a few hours on a few days per year in total. So this increased temperature cannot be a factor, not a large on at least. The specs allow up to 55°. I have two cells inside the house next to the wood fire to warm them thoroughly to 25° and will test them again with the original tester EBC-A20 afterwards.
@@hummmingbear All cells which have not passed the testing are 'rejected', 'B-Grade' or 'Storage Grade' cells, whatever you want to call them. Some sellers have them as 'A-Grade " cells on offer. Are they still A-Grade? I think so. We have certified cells and A-Grade. What a nonsense, ey?! 😂
It is hard to say if the are bad. This is seen from the standpoint of View, I purchased 44 Lifepo4 cells Thunder Sky in 2011 160 Ah. When they were new they had about 180 Ah. Today it has 155 Ah. These cells has been mistreated in many ways. Thanks for your open and honest videos. 👍
Hi, oh! it's really very interesting!! your cells are now 11 years old! and she don't have almost no loss of capacity, compared to the standard 160A! Indeed they had 180 Ah when they were new, the difference is more important, but after 11 years of use, 155 Ah for batteries, validated by the manufacturer at 160Ah, it's impressive! Did you buy these cells directly from the manufacturer? Thanks.
@@OffGridGarageAustralia I think warm test will increase around ~2.5%. I can see this in my car even the battery is not the same. I doubt that this one will behave different.
Very insightful video Andy. Congrats on topping 35,000 subscribers! My thoughts... For the extra amount you would pay for top tier A+ batteries, you can buy a 2nd (and probably 1/2 of a 3rd) set of storage grade batteries. You're doing it the right way. The capacity, for the money, will always be 2x that of A+ grade batteries.
Thank you, I almost forgot about the 35.000 as a milestone, wow 🤦♂️ Yeah, you can really buy a lot more storage for the same money using these storage grade batteries. I think, they are perfectly fine and I don't mind a bit of extra maintenance and testing. I would have done all the testing anyway just for myself.
I appreciate your transparent and objective approach. It would be interesting to see if this changes during the summer. Although that rate of degradation isn't necessarily alarming given how much time has passed, in my opinion. Still far better than other battery systems I have used. Edit: imagine getting these results if you had paid that 50-70% premium for the "real" A-grade batteries! Ooof!
I have three of the cells inside the house now and will repeat the capacity test with the same tester I have used inititially with these cells. Results will be in soon...
The voltage slump test correlates well to AH capacity degradation and condition of cell. Just be very careful of external connections resistance causing extra voltage drop. Ideally voltage is measured directly on base of cell terminals. 1 kHz battery impedance meter primarily measures only conductive impedance and does not include the more significant ion transfer impedance. 1 kHz impedance meter is good for checking for delamination. When electrode material delaminates from the aluminum and copper foil the 1kHz impedance meter readings rise. Ion transfer impedance is the primary degradation as cell ages. It is caused by the growth of the protective solid electrolyte layer increasing resistance to ion migration resulting in greater voltage slump with moderate cell current. The growth of SEI protective layer also consumes some of free lithium reducing the available lithium for cell useable capacity. Every time a cell is cycled there is some small amount of fracturing of SEI protective layer that is repaired by regrowth on subsequent charge cycles. The regrowth consumes some of available lithium gradually reducing cell capacity and the increase in SEI thickness increases cell total impedance over time. Capacity loss over time is not the only aging factor. As cell impedance gets greater it limits the practical maximum load current the cell can support.
It worked ! I discharged to 20 percent today for the first time. I put in two parallel units this morning. The voltage averages and the capacity sum. Now my battery is good for at least 80 % of the battery's amps. The only reason it did not go lower was the inverter determined the battery was 47 v. The lowest cell was still 2.708 volts. I will be building a second 280 a battery and this should give me 680 aH, enough storage for full off grid solar power. It is not to big , still small enough for the panels to charge in a day.
Great testing. Fortunately I started as you with a spread sheet. With top equipment now,, As I get batteries completed I'm going to start a cell swapout/testing. Keeps me busy and batteries in top condition. Older cells will be matched and put together in a battery. No hurry using the ebc-a20. One cell purchase as needed I consider maintenance costs.
I think your results are great considering the COLD temperature , I would expect at least 5 % loss from the cold , more actually . But you made a good point , we need to document the temperature of the cells when taking data points for the spread sheet . Thanks for reminding me.
Yes testing only with the same temp, because these cells perform different under different temps, 25 would be nice, otherwise the test would be useless.
You could always sell these batteries as "Used grade B". Lesson here is have a good way to test the batteries you purchase and ALWAYS test capacity when you purchase. I just noticed your hard drive magnets holding your pliers on the bench wall - LOL. Love it. Perhaps, use a heater to warm one battery to "summer time" temps and re-test? I wonder if the capacity would increase. These may be summer-time-only batteries. Thanks for sharing
I probably would not sell them, no. I will continue using them and do more testing over time. They are now a good source of information and can help us better understand the history of these cells and how they will perform over time.
@@OffGridGarageAustralia They could make nice ups batteries no? A UPS only has to run a short time, so capacity is less a worry. :) How many computers or emergency lights do you have? :P
I really beleive the deviation on your results respect standart conditions is noticeable but not abnormal. 11°C is starting to be quite cool for the batteries. So wirhout another CRAZY week of testing would accept those results as within the normal degradation values. Thank you for such a Crazy testing!! Again...;-)
Thanks Luis. I think the batteries were actually warmer than that. 40A applied for hours is creating quite some heat inside the batteries but I will repeat the test with warm batteries soon.
@@OffGridGarageAustralia Yes, totally. They warm up both 11°C as well as at any other temp you operate them. So there will always be a slight deviation respect ambient temp. We will seen then what comes out on the next test. Thank you again for such a fun!!
Excellent video. You are a goldmine of information! Please heat up a couple of cells and simulate a “summer” test. Also, if you can put them back into service, more valuable lessons will come from it. Thanks for sharing your efforts!!
I purchased my first 16 a few months after you and I tested every cell. and then purchased 40 more (wanted some spare ones ) and retested every single cell all the old and new cells. Surprisingly the old cells was only down 3 to 6 ah lower than the first test. And was conducted in similar test conditions same temp and same tester. The newer cells most tested lower than what the old cells was still testing at.
Thanks for sharing. It's very hard to find common sense with these cells. One deliver can be totally different to another one from what people are writing here.
My CALB lifepo are 6 years old in my full time RV compressed. My bank is 8 cells 180 amp/hr ea. for a bank of 360 amp/hr at 13.2 volts. I tested mine 2 months ago. They are always within 10 millivolts at full charge. They have lost 3 percent in 6 years. I love CALB because of the robust case and the large terminal connections. My EVE battery has already stripped out 2 connections and runs almost 80 millivolts delta after only one year, they are compressed BTW.
I suspect I live quite close to you (little mountain) and have been following your exploits for a while now. I have been inspired to some extent having filled my shed with 16 x 250watt panels which gives me quite some additional power. I have recently bought a Growatt spf 5000 es and a couple of 6kva 48 volt lifepo4 rack mount batteries from china (currently being shipped). I also have an existing 10kw grid tied system using 2 sma 5k inverters. I am building my off grid system to take some of my electrical load off grid. keep up the great work. my son just ordered a new Tesla which is going to be delivered sept-oct.
Thanks a lot for sharing. Sounds like a great setup you have over there in Little Mountain (3h drive from my place). What brand did you get of these 6kWh batteries?
Looking at the EVE product specifications for the 105Ah battery, shows most test done at 25c +-2. They also show Discharge-ability at different temperatures. It might be worth having a look at the battery manufacture specifications when running and comparing performance test. Enjoy your educational videos Andi.
It's standard practice to use consistent temperatures when testing electrical devices. That temperature is usually 25 degrees C. I look forward to seeing another test with consistent temperatures. I have not experienced any problems with any batteries that I have tested, but I also run a business so I can imagine I get better treatment because of this. I find these videos very interesting, thank you Andy, keep up the good work!
Thanks for the video. We don't have many people who are actually doing the science, so when we get lucky to have someone like you it's great. As for all the Temperature comments etc. Yes it would have been ideal, maybe you can test a single cell again and see how much it changes. As for you final question of buying Tier1 battery packs versus buying these Grade B cells, I would have said 6 months ago get the Grade B and save yourself the cash. As of right now my thoughts on this are changing. Lots of info is coming in saying that there is going to be a massive shortage of batteries in the future and also all these new Technologies like Solid State batteries seem to be in problems again. So right now I would say bite the bullet, spend double the money and get cells that will last 13+ Years with good performance, because that may be how long it takes for this whole thing to settle down and prices to drop down to dirt cheap levels again.
Thanks for another straight forward no deception video. Love your channel. As for the batteries...Reassemble 1.0 use it. The information I personally gained from watching your struggles with 1.0 was priceless. So use it until it no longer functions. The early days of 1.0 was just that the early days. So yes a bit of Tom Foolery from china as buyers were beta testing the battery's. Nothing can be done today about what has happened in the past. Take the knowledge gained and not allow the same things to happen. I would consider these as 265ah batteries and be happy they still work and know I should get another 15 ish years from them. Or you can simply make 12v battery from them and use around your property. But during the summer you will have way to many amps out side and 2.0 will be full. I personally would reassemble with copper bus bars 48v and just add the capacity to 2.0. but knowing I could put in wheelbarrow and move it around the property. Perhaps 1.1 48/12v on a dolly to run the wood chipper? Love your channel have a great day Andy Gruetoo
Thanks Gruetoo. I will definitely keep using these batteries and 'transform' them into Battery 3.0 soon. If I charge my other battery fully ins summer time, will have to see. I have also huge loads which currently still run on grid during winter. It will be interesting...
Thanks for the video. I'm capacity testing lifepo4 batteries everyday and using different testers. These results helps me understand how critical the environment conditions and testers are.
I would take cell #6, warm it up to say 25C and retest it to see how big the temperature effect is. If fact I would likely do several different temperatures to see if I could generate a capacity vs temperature curve. That would likely require building an insulated, heated box for the testing, but the results would be very interesting.
The question that comes to mind; What new storage technology will be available in 2, 3, 5 ,10 years from now. In just a few years the storage capacity of Lifepo4 prismatic cells has gone up leaving the 280ah cells at a reasonable price point compared to 300ah or even 320ah batteries. By next year, or the next I expect 320ah cells will be falling behind whatever is the newest on the market. That would mean the 280ah batteries will even be less in price. So, you could look at what and when do you want to upgrade. Solar panel technology is getting better, BMS' are getting better, and batteries are improving. Build your system to make it easier to upgrade. The 280hr batteries that are in the system now, may be good for 15 years or more even if they are class B cells. But, your system is not a forever system. So, build your system to be ready for the next upgrade. Clear away the cobwebs in 5-6 years and buy 320ah or 400ah or even 500ah batteries.
Thanks. I won't upgrade my system just because there is a new technology coming. I think LiFePO4 is good enough for our solar storage projects, they are safe to use and great in price. I will just keep adding storage as I need it for now and definitely keep testing these cells form Battery1.0. We have now a good start data with them and will see how they perform over time.
In my offer from Basen I got 120ah cells at a better price per capacity than 240 ah cells. I believe smaller cells are actually better for a setup because you have smaller modules and hot swapping is easier and the heat losses per cell (and/or connection) are lower as the connectors are the same. Redundancy is also better and so on.
Hi Andy...mmmm....classic problem....I have same with my cell N.7 a N.13 same... 200A cells The cells no lost capacity...they Never had,since you bought them!... This is a classic problem when order online!! I appreciate what you doing with some online sellers,now,asking to test and macth cells before delivery. Other big problem is : when you buy the battery,if something no good,is not easy to ship back to China,because shipping cost are very hight , when you send back goods,but when you buy goods,shipping cost are very cheap! This is what online seller knows very well! Baba should change policy and make refund goods shipping costs cheap as buy ones....
Off topic but since this is your latest post, you may read this:- I have followed your UA-cam channel with interest. I have always wondered about using lower charge voltages to reduce battery stress. But also wonder about using the Equalisation setting to bring the battery back up to 3.6V/cell every 40 or 50 days so as to top balance the battery every so often.
You can also parallel small cells directly with the lower capacity large cell(s). Just use the same chemistry (ensure the voltage is safe in the same range as the pack cells) and realize it may not support the same max current during charge or discharge as the big cell. For example, you might pick up a 10Ah cylindrical cell and parallel it with your 255Ah cell and now you have functionally a 265Ah cell.
@@OffGridGarageAustralia bit if same chemistry and assuming when assembled they are balanced they will simply act as one larger cell... Can't see a problem. Could put a fuse in with smaller cell to protect wiring. This will mean your whole pack is now as small as the next smallest cell.
It would be interesting to: 1) test the remaining batteries 2) have them join the "new" ones, and be put in production again 3) test these batteries once per year This would give us all some solid scientific data. If you buy a second of these 40A testers, you can halve your time on testing these cells. And if then one of them dies, and is not repairable, the other can still perform the same duty for a while longer. Ensuring consistency for a few years longer.
If you’re only charging with solar is capacity an issue? Cloudy days it may not 100% charge anyway. I say run them as hard as you can and it is what it is. At the 10 year mark either they will be replaced with a different chemistry or priced down to replacement isn’t an issue. Who knows what the future holds but it is interesting to watch. You don’t monitor the performance of your car engine or the efficiency of an AC unit year to year so what’s the difference? Buy it , Use it and be happy. As far a grade B cells I think they are used cells that still have storage capacity. They aren’t probably warranty replaced battery’s from ev. Thank you for your videos sir.
Yeah, I will definitely keep using them and they will be going into our battery 3.0 soon. But I will also keep testing them from time to time to learn and share more about these cells.
I know you don't like the idea of compression, but too bad you don't have another similar group that's been under properly spring-loaded compression this entire time to compare these to!
I can freely program the EBC-A40L and also include resting times. The voltage sag while resting is an indication of age but we would need to start colleting this data and see over time what it tells us. I have some spare cells lying around and may think about setting up a test environment at some stage. There is just not enough time.
10% capacity loss in 4 years is really good actually. Especially with that many cycles. Speaking for somebody with a bank of AGM batteries that spent their entire life as fully charged standby batteries that got used maybe a few days a year, and are around 50% capacity loss after 8 years with about 1 cycle per year.
12:30 with all the B drama, I will not be buying any more EVE cells in the future. 17:00 a few days ago, I was discussing about temperature with some local users, how it affects LifePo4 cells in general and why we should keep them cool. One particular user was not concerned. He opined that his battery can go up to 70℃ while my EVE can only do 55℃. I honestly could not argue against his claim considering 70℃ is guaranteed by his factory-made-batteries. I could not even claim 45℃ from EVE. Whether 70℃ is guaranteed or not, said person was confident with the factory warranty to abuse his batteries. Maybe I will stick to buying factory made batteries. more expensive, but carries warranty that is hard to beat.
Just placed another order for a second round of 48 304's yesterday. Coming on the heels of your notice of the new MD30 cells coming out. My supplier at Luan finding out from EVE that they are swamped by a buyer blocking anyone else getting the new cells for the time being. But after sharpening her pencil Amy hooked me up with the cells $500 bucks under the cost of the MD30's after shipping and yada yada yada. Quite happy with that. The cells she's sending me are babies at 2 months old. Even managed to snag 3 more JKBMS's from JK for the price I paid for 2 last time I ordered. Sheesh, on a roll..... lol Hey, if I can get 16 years out of them they will probably outlive me. That's a plus in my book!
I really like your videos, they are most useful. I have put two other comments on here today about the awful batteries I have just received from an Al*Expr*ss seller, but they seem to disappear. I bought 16 New Grade 'A' batteries, and what has turned up is 16 pieces of very old, discharged (2.8v), bulging cells with corroded terminals. I would give my left arm for some batteries as good as these!! Best wishes
It seems like a temp regulated battery box would be a good idea to eliminate that variable. If you use Tesla's claim of 8% loss in 10 years, that is ~.8% per year. 5% to 8+% loss over 4 yrs seems quite high in comparison. It may be a good idea to test one of the QSO cells at this time to see how much of a loss they are showing vs time. Thanks for the update & keep up the good work!
Well, I think these cells are just fine. With about 5% degradation in 4 years they fit their specs. I believe, that in a normal solar storage the aging of the cells will kill them before they will be killed because of the cycle counts. But a cell with 80% capacity is still good to use, it just has a lower capacity. During aging the capacity will decrease and the internal resistance will increase. So charging and discharging at a really high amperage will not work as good as with new cells. But when do you really need a very high charge or discharge with about 1C? And if you parallel batteries the need for high current will decrease, so old cells will be usable even longer. And these cells have been tested now at colder conditions than before, so there will be a capacity loss because of lower temperature. It would be nice to know how much it is. Maybe you can test one of the cells with higher degradation in your house at about 20 °C cell temperature to see how much the different temperature causes.
Thanks Gunther. I have 2 cells in the house now warming up and I will repeat the test with the smaller tester when they have the 25° for a while. The purpose of so called 'second life' battery is exactly for energy storage, so if batteries are being used in an EV for 15 years, they are still great for storage projects afterwards as you said. Just the overall capacity is lower.
@@OffGridGarageAustralia Make sure that you leave the cell in the warm house quite a bit longer when the outside surface temperature reaches 25°C (to also heat internals of the battery). 1 more day after suface temperature reaches 25°C i would say.
Hi, Well, to be honest, I am surprised they didn't degrade further during this time, they were treated badly with deep discharges to the cut off voltage of 2.5V. I do use industrial grade cells in my setup from Winston Thundersky (1000Ah cells at 1C, quck chargeable at 3C, max. current 10C for 10s what means 10000A, it is a nice little 12V 15kWh battery) and the data sheet gives them 2500 cycles on full discharge (they get damaged when discharged below 2.5V or charged over 4.0V), 5000 cycles at 80%DOD (it is about 2.8V cell voltage), full at 3.65V, regular operating voltage 2.8V to 3.8V. They deliver at 0.5C charge / discharge current about 1300Ah between 2.8V and 3.65V, they are expensive - like 1$US per Ah per cell, but totally worth it. My bank is in daily use as liveaboards, it has delivered in 4 years about 473000Ah or 6400 kWh, it is cycled daily about 50% - 60% and has still 1200Ah between 3.65V and 2.9V - this is my shut down setting. LFP cells not only degrade when kept at high voltages, but also when deep discharged. So you are kind of lucky to have lost only 5% of the initial capacity in average. Thanks for making videos and tests public, that debunk a lot of myths around this exciting technology.
'treaded badly"? 2.5V and also 3.65V is within the specifications when I did the few tests in these regions with the cells. And only the weak cells were going down that far, not all of them. This should have nothing to do with it.
don't throw money on "industrial batteries " buy candy for the baby. let us not become snobs over a technology that delivers energy. this should be cheap and exchangeable.
Interesting results Andy. You were new to all this and still trying different things (being a sort of guinea pig for all your viewers) when you first tested the cells. Some of the cells were sitting for two years before they even got sold/used. I wonder what the rate of degradation is for cells in storage vs cells in use...? In the brief shot of your panels in the yard I noticed that some appear to be poly and some are mono. Have you ever checked the output to see which performs better in your area? You have mentioned that a slightly hazy sky (diffused) seems to give you the best output for the panels on the roof. I remember watching Will Prowse do a test on some 100W panels with partial shading and surprising results. I thought it might be interesting if you tested some of your panels (poly/mono) in the diffused lighting you seem to prefer.
Thanks a lot. Yeah, we have come a long way in the last 2 years and learned a lot about almost all aspects of batteries, solar and everything in between. I think it's great to have this platform here to share the knowledge and findings. I cannot see a big difference between mono and poly. They have different voltages so I cannot connect them to on one SCC. So, to be clear here: Full sunshine in winter and the shading on my roof is the worst situation for the panels with least power output. Cloudy winter weather is far better and I easily triples my output for that day Full sunshine in summer is... hallelujah Cloudy summer weather is better than cloudy winter weather but not as good as sunny summer weather. But a panel test video is next on the list with some very special panels...
@@OffGridGarageAustralia Thanks for the reply and description of the worst to best solar situation for you with regard to time of year/cloud cover. Are the garage roof panels a mix of poly/mono? I wouldn't expect you to mess with those (they are all set up and working). I just thought the solar fence and others you have laying out in the yard might be fun to test. Will used an MPPT SCC hooked to a 12v LiFePO4 battery at a low SOC and just connected each panel individually. (video is called "Mono vs Poly - Real World Test - Worth the $$?" if you have not seen it) The surprising part to me was that the poly panels ended up outperforming the mono panels in every variation of shading he tested... up to +30% in some cases. From all I read about the mono panels the general opinion was that they were superior in full sun and shading, but in real world testing it didn't work out that way. Maybe under standard test conditions they perform better but in actual usage conditions they don't. Whatever panel testing you have planned I'm sure I will enjoy - looking forward to it.
@@gumpster6 Yeah, I've seen his video. I have polys on the roof as they all are 60-cell modules. The monos I have are all 72-cell modules and therefore having a higher voltage, so cannot mix them on one SCC. The pool fence is connected to its own SCC because of that.
Those look like great results to me. Were these cells used in that time, cycled on a daily basis? If you still have 80% capacity after another decade that is absolutely AMAZING VALUE.
Pinch of salt 👍 you don't put a grain of salt on your meal or in a pot 😝 Interesting results though 🤔 Here in the UK, its been 25C+ 🥵 You'll have your summer back soon 🥳 Love your videos, always looks forward to a new vid and i enjoy watching your older vids to 😁
It's like 'without further to do' and 'bended', glad you picked this up 😂 Solar is already producing more power every day now, I can see it on the VRM. It's great.
108 degree's fahrenheit in Fort Worth, TX today. At the end of the day. I think I will buy the less expensive batteries again. Although at 62, I expect my new qso (purchased 11-2-2021) A? 16x304AH EVE may last longer than me. Or not, who knows I could live to 120.
"The "Infamous" Cell #6..." Running some rough numbers: - Given your test results Andy, of about 5% degradation in 75 cycles (about 0.07% per cycle) I figure 286 cycles until you hit 20% degradation, or roughly 3.8 times your 1.2 year test, or 4 to 5 year lifespan right? - Assuming that a a 280ah, 16S pack costs about $2,500 U.S. and lasts for only 300 cycles, that's $8.3 per cycle cost right? - Divide $8.3 per cycle by 14.3kwh, would be $0.58 cents per 1kwh to store and use free sunlight, is that right or did I miscalculate? If, however such a pack lasts for 1,000 cycles that drops the storage cost to $0.17 per Kwh, and at 3,000 cycles to $0.05 per Kwh. Looking at the numbers for a Tesla Power wall warranted for 10 years, at one cycle per day, that's 3600 cycles at 13.5kwh per cycle. at about $11,000 for a 13.5kwh Powerwall that's about $0.20 per kwh storage cost. If the EVE cells can manage 3000 cycles and 10years, then you are way ahead of Tesla for cost effectiveness, at 1,000 cycles maybe equal, and at 300 cycles three times the cost of Tesla. As my average power cost here in cold, wet and dark Oregon is about $0.18 per kwh considering the investment cost, it's more cost effective for me to buy power, or use solar net metering and no storage. If my figures are correct, then getting real life cycle life degradation data could be useful, Maybe put an automotive grade and reject grade cell in a test bench and cycle them three times a day for 100 days and look for a result? Considering the cost of cell degradation, with current battery storage chemistry, perhaps compressed hydrogen generation and storage and fuel cells could make sense, and why the rush for solid state battery solutions?
Thanks for these videos. I was wondering if the 40A tester in this video could also serve a a charger for initial cell top balancing, and then for 48v pack charging if needed? If not, do you have a recommendation for a 48v lifepo charger? Thanks!
I kept getting distracted while watching this video I might have missed but did you check the internal resistance more recently or in the spreadsheet are the internal resistance values from when it was first delivered?
Another great video Andy. I have one cell in my diy battery pack that acts like your cell 6. I added a 8 ah headway cell in parallel with the low capacity cell. This adds 8 ah to that cell which stays closer to the capacity of the rest of the pack. I would like to see you try this with cell 6 and see if that makes a difference.
Be very very careful with that. You could have a very high current from the large capacity cell to your much smaller 8ah cell and nothing will limit it. People have suggested this to me but I think it is unsafe.
@@OffGridGarageAustralia I though you did something similar with a low ah battery connected in parallel to a higher ah battery? So why wouldn't a low ah cell in parallel with a higher ah cell work? The voltage between the two parallel cells are equal.
@@douglasmarquis3446 Nah, this was just for testing to see what happens and I did this with a 4s config in parallel and a BMS for each battery. That was the 4s 304Ah in parallel with the 4s 5Ah PALO cells in parallel.
@@OffGridGarageAustralia But that would only be when you first connect them if there was a significant voltage delta between them, true? So as long as you make sure they're very close in voltage before connecting them, it shouldn't be a problem. Once they're connected and equalize to the same voltage, that problem is gone forever, I would think.
Hi Andy! and thanks again for this video... And this one is even more interesting!! You must have asked yourself the question? what were your battery used for, for 2 years before you bought them??!! I think that not only manufacturers resell cells that have not passed the Quality tests, but I also think that they resell cells that have already been used, replaced under warranty by them, in uses for EV (car, bus etc ...) they have very important contracts, with car manufacturers, and replace battery packs under warranty, this is part of the terms and conditions of sale of their cells. If we look, more positively, for our use in solar system, these cells remain I think acceptable. One thing worries me a bit is that often the battery start to show signs of weakness (reduced capacity) often gets bigger and faster...?? The solution is I think, just replace the weak cells, and continue to use the pack normally. Andy, the more I watch your videos, especially the latest ones about cells, the more I learn about the longevity qualities of cells, I really think that if we want top cells, we have to buy them from the manufacturer. they are expensive but certainly that for a long use, without worries, it is the solution. I no longer have any confidence in these resellers, who only lie. (now we know what we are buying?!! and it's a lottery!)
These cells were new when I got them as far as I can tell. Otherwise the terminals would have some sort of marks, scratches or sign of a busbar being connected. But these ones did not have a single scratch or mark.
@@OffGridGarageAustralia Ok Andy, but I think they are smart enough, to hide anything.. Originally the terminals are not drilled or threaded, (because I think they are welded into the EV packs) it's easy for them to resurface the terminal, make the thread hole, and a new packaging, the blue insulation and the black top cover.. And there! apparently it's a new cell😜 (they buy laser welding machines to weld new terminals.. It's child's play for them to make a cell look new! 😁
I have bought 2 Narada 48NPFC50 back in Nov 2021 & another 2 Dec 2021. Both sets have different voltage profile and first set don't have manual circuit breaker. So the first set is always discharge faster and went into protection mode then the second sets. Out of no choice, I installed a smart timer for the first set of batteries. They were cut out of the system in the middle of the night then back on early in the morning. The second set of batteries works thru the night. This might be the solution for battery that are parallel linked.
Thanks for sharing, Michael. That is very interesting as some people here leave comments saying the server rack batteries are the solution to the DIY stuff we're doing. I was always very sceptic about that statement as you never know what batteries are in the metal enclosures either. So are yours not in parallel but different systems?
@@OffGridGarageAustralia All 4 batteries are parallel together. It's clear the first 2 sets are the older version as they don't have manual cut off switch. I have been running them down to 48v. Battery manual says it can be run till 42v. Only one of the older sets keeps going into protection but it always comes back after reset. The batteries seller said only run till 50v. But at 50v cut out settings on grid tie inverter, sometimes that batteries still went into protection. The other one same model it's just low voltage. They newer model sets was showing 2 green LEDs out of 4. I am suspecting grid tie measurements inaccurate + power draw and both set batteries have different voltage profile + capacity.
@@OffGridGarageAustralia There is RS232 port on the batteries. In the manual it says need to make the wire. Plus needs to get the software from Narada.
I think they’ve done ok Andy. I see a big difference in capacity with temperature so in my opinion this is quite acceptable. Put them back in the tub with regular BMS + a Neeeeeee balancer or JK and call it good. Charge them to 80% and they are a good standby for when SHTF.
@@OffGridGarageAustralia Hi Andy, you've already mentioned 'our Battery3.0 project' a few times in your comments and videos. It makes us very curious. When can you give us a sneak peek of your new plans? Kind regards.
Hello. First of all I congratulate you and thank you for your videos which taught me a lot of things. However a question remains in my head: is a communication mandatory between the BMS and the inverter/charger? Please accept my greetings.
Bonjour ANDY, après les vacances et des occupations personnels je suis en libre pour continuer l'aventure avec OFF GRID GARAGE 😉, je reprends les vidéo par ordre de publication. Belle analyse pour la batterie 1.0 👍
I am about to install LTO cells in my car, for a starter battery, so I am super curious if they will last as well as they allegedly should, when used hard. 10c discharge (for 2 seconds max), some heat in an engine bay (living in QLD). I really hope LTO as a chemistry is the holy grail of "forever" batteries..
LTO is def a better chemistry for the hot and cold cycles of a vehicle. I use lifepo4 due to the voltage difference and they've held up fine for a couple yrs but I have to watch the temps
Hi Andy, I don't see 5% over four years I see 5% over two years. The period before you purchased them was storage mode typically 20-50% and therefore only a few cycles. The temp difference is a big factor in the results so not so bad. André in Sydney
If you freeze in the workshop I have an idea. A solar panel gets hot, make a box behind the solar panel and circulate the air from the workshop into the box and behind the solar panel and out into the workshop again. Great work with the batteries. Best regards From Denmark.
Second. Just completed the capacity test of the second cell of my "brand new grade-a" cells from Basen. Ordered end of April 2022, received this week. First cell 289Ah, second cell 278.8Ah. One out of two already below 280Ah. Tested at 20°C. And the ZKE Tester does only test at 0.14C and not 0.5C as per spec... Also, one cell was delivered with only 2.7Ah capacity left (2,8V). At least the only optical anomalies are very small dents and small pucture foil damage. All cells are from 2022 except one from 28th Dec. 2021. Very brand new grade-a. Update: Third cell 280.5Ah. Just passed requirements.
Hello. As an example, can you calculate the amortization period of the purchase cost of a current Lifepo4 prismatic cell with the current electricity unit (kW) price? After how many cycles can it hold as much energy as its purchase price?
Having the same experience, building 48v systems with 20 cells. The 4 extra cells are in parallel with cells 1,8,9,16. When a cell goes wonky, over charge cutoff6or under charge cut off, it is swapped out with a spare cell.
I haven’t seen the video where you must have found out the cells were already 2 years old. How did you find this out? Also if you are concerned that these are not grade A cells, have you removed the black covering on the top of a cell to see if there is another QR code on? I will be interested because I’ve just bought 16 x 230ah cells from Docan Technologies as grade A and they have said they are brand new unused. These also have an intact QR code on and the black cover. Great channel by the way, learning bits from all over about battery building.
For people like you with multiple strings surely you could "just" capacity test all of them and reshuffle them into "the big battery", "the medium battery" and "the little battery (that couldn't)". It would only take a couple of months and after that plus a lot of faffing around you'd have slightly more usable capacity from your three strings. Totally worth the hundsreds of hours work!
Hi, Endy! What is the condition of your battery 1.0 cells now? It would be great, if you make new video with new capacity test of that cells. Maybe, degradation is at around 10%?
The biggest issue you have is that the cells are not closely matched which results in more maintenance. I changed mine out for matched and batched. With a 16 cell system everything balanced to 10mv without all the maintenance.
Well, once they are top balanced, it should be fine and the BMS and balancer should take care of the rest. The lowest capacity cell still determines the overall capacity of the whole battery of course. But, hey, for that price... 🤷♂️
It not just the capacity. If the cells are not well matched in the first place they will drift even after top balance. At least that has been my experience.
So would I be right in saying it would have been better to cycle these more maybe 700 cycles rather than 75 over the 2 years? I have been watching your videos over the last 2 months and getting quite excited to start my own system so would just like to say thankyou.
Thanks Helen. If you cycle them 700 times you will see even more degradation. On the other hand you putting them to a good use and if you charge them from solar, you would have saved a lot of energy. Charging and discharging them twice is not easy though but could work for certain applications and setups.
generally LiFe batteries are rated by manufacturers to be usable down to 0degC, however recommended between 15 to 35degC, colder temperatures will decrease usable capacity, and risk lithium plating of the anode with higher discharge rates at lower end temperatures (permanant damage), in short, the 6-8% drop in capacity at10degC over the rating (likely speced at 25degC) should be expected. try re-test at 25degC?
I wonder If it is right to call it degredation considering that the 280 Ah you use as beginning is right or not cause such battery cell that did not met the EVE Automotive Grade might have been sold due to too low capacity at 279 Ah. I have only checked the equation for that 266,x Ah cell which equaled 95,1% capacity compared to 280 Ah and 4,9% loss in just 2,33 years of use. Wouldn't it be better to compare the 266,x with your initial capacity result from 2020? That ist real degredation during your usage and you do not know how badly these cells were used in those 2 years before. Or did you test that 266,x Ah battery back then accidantly with 280 Ah? Sorry, i'm only using my phone and can Not really read or access your spreadsheet to cross check that formula. I also suggest to keep an eye of the ambient temperature cause from 25°C to 0°C a lfp cell will loose roughly 20% . 6° less than first Test in Sunny australian summer and you might get 5% less . Same as range of ev drops by ambient temp. in Winter and can double in summer. Too few yt measure room temperature curve during discharging even though everybody should now that above 25° C the capacity stays the same It is time to emphasize it again to avoid false conclusions. I had seen such drops die to temperature. Check the specs sheet curves EVE had released back then. Might help to get it right, measuring at Dame season and similiar temperature.
question is how many cycles have they run in total? ive extensively used lifepo4 cells, especially 18650 cells, their promissed life span of 10 years seems over estimated, ive seen around 5-6 years of life from them. i didnt count cycles on them, as that would be hard but they were charged with around 0.25 C maximally. i think 1000 cycles down to 60% capacity seems to be the standard from my experience.
@@OffGridGarageAustralia discharge down to 3V, and charge up to 3.6V its a solar product so it uses the sun, taking minimally 4 hours to fully charge, but usually more, so 0.25C or less as the charge current. whe've made millions of these, and i can tell you the claim of 10 years or 2000 cycles i think cannot be had, but its directly proportional to C-rates, the faster you charge or discharge, the lower the cycle life of the cell. the numbers given by manufacturers are theroretical calculations based on accellerated aging tests, where obviously they try to make things look as rosy as they can.
Hola: mi mas sincera enhorabuena por estas páginas tan interesantes y de las cuales he aprendido mucho; GRACIAS y Enhorabuena. Ahora si me permite un comentario relativo a este problema de los contactos. Permítame que le sugiera si la pasta anti oxido de aluminio es conductora o realmente si Usted mete la puntas de su polímetro en el tarro de la pasta anti óxido, este le indica falta de continuidad o por el contrario le indica como buen conductor. Si el polímetro le marca que esta pasta es aislante, ya sabe, es mala, no la use. Quizás lijando y después usar pasta de aluminio conductora y antitérmica, la misma que se usa para los procesadores del ordenador, quizás funcione. Perdone intromisión. Un saludo desde España.
This is the reason why i measured all of my 48 cells ahead, to put the closest ones together. And 5 of them reached the claimed 304 Ah. So i would not say there has been much improvement...
The problem you have is that different testers were used before. Even if you used different wires in the test in the past that would affect your Ah readings. You could average the cells and do a 4s4p system as a backup for priority loads.
With some A Grade CALB cells now over 10 years old I can confirm that capacity loss does stabilise and that to minimise capacity loss store at around 30% SOC where natural discharge is very very low.
Wow, I wonder what happened to those low cells? Initial manufacturing and not properly sorted to get you a matched set? Some individual abuse while in your care?
I have only ever used these cells as a whole battery in a 16S configuration. I did some initial testing with cells 1-4 though but these are the better ones in the pack now 😊
I'm sure everyone is saying it, but cold vs warm test is definitely required to see true test between cells at different temps! Thanks for the videos! I can't tell you how much I've learned from you and this channel! Thanks Andy!
Warm battery test currently on the way... 😉
nominal capacity is on 20C, on lower temps can be different, and o low temp need to lower currents. I have 176Ah lifepo from Aliexpress gradeA, 3 years run on solar system, 700 100% cycles calculate by charged/discharged energy and by victron smartshunt i charge it to full, sync SOC to 100% and discharge to 2.5v per cell and discharge 170Ah.. its really good result. My 300Ah cell is too young for any wearing test.
What about taking cell 6 and the tester into the house, let them warm up to room temperature and repeat the test, that should show if temperature is a contributing factor.
I could be incorrect but charging/discharging at 40a does 'warm up' the cell. True in freezing temperatures operating the battery may be a problem. Maybe Andy could retest with the cell in a heated 'box for a test. I personally found the battery performs well at 80f.
@@krg038 red deutsch
@@krg038 That is correct. The temperature I measured and showed in the video was of one of the cells on the workbench, not one I have tested. They are actually getting a bit warm during this test with 40A.
I've got three cells inside the house now and will test them again with the original tester (20amps) so we can compare better.
@@OffGridGarageAustralia IIRC lead acid batterys have 2 or 3 quotes on AMP HOURS. 10 hour, 20 hour and 100 hour.
As LiPos the same? Do they provide more amphours if drained slower?
@@TechyBen The discharge rate has minimal affect on the number of amp hours available.
Instead of just randomly speculating, let's do some math. For one, the EVE datasheet states to expect a cycle life of >=2500 without fixture ('compression', yes, I know...) and >=3500 with. So we already increase our normal degradation by 28% by not having the cells in a fixture. Secondly, find some temperature discharge curves for LiFePO4 for example from Nordkyn et al. You should expect at least a drop of 2% at your current temperatures. Finally, a couple percent calendar aging. This also depends on temperature: the higher the temperature your batteries sit at, the faster the degradation - since you're in sunny hot Australia.... The literature has several models on this, but there are numerous variables I can't account for, but a couple percent is not out of the ordinary over the 4 year life since manufacturing. Based on all of this, 5%, or even 8%, doesn't sound bad at all. It would be good to do a capacity test again at 25C to at least remove that variable...
Wait!
Firstly, this cycle increase they promise with fixture is only valid for 1C charge and discharge cycle (or 0.5C with other cells like the 280Ks) as per their test conditions. So unless you do that in your daily usage, you cannot compare it to what is on the data sheet. We know, lower current is causing less degradation.
Also, all these specs form the data sheet are only valid for certified cells, not to rejected cells, I believe. (except the voltage, current and temperature values of course, they still apply).
Secondly, even we're in 'sunny hot Australia' it does not mean these batteries are actually getting that hot as many would expect. Most of the time, they are at around 20-25° while they may get 'hot' as 38°C in summer for a few hours on a few days per year in total. So this increased temperature cannot be a factor, not a large on at least. The specs allow up to 55°.
I have two cells inside the house next to the wood fire to warm them thoroughly to 25° and will test them again with the original tester EBC-A20 afterwards.
@@OffGridGarageAustralia Dammit, YT removed my reply... I'll see if I can find the energy to rewrite it.
@@OffGridGarageAustralia do you consider these cells, or even EVE cells from Doucan "reject" cells?
@@hummmingbear All cells which have not passed the testing are 'rejected', 'B-Grade' or 'Storage Grade' cells, whatever you want to call them. Some sellers have them as 'A-Grade " cells on offer. Are they still A-Grade? I think so. We have certified cells and A-Grade.
What a nonsense, ey?! 😂
@@OffGridGarageAustralia I guess my question is are the EVE cells these companies are selling rejected unless you buy them straight from EVE?
It is hard to say if the are bad.
This is seen from the standpoint of View, I purchased 44 Lifepo4 cells Thunder Sky in 2011 160 Ah.
When they were new they had about 180 Ah.
Today it has 155 Ah.
These cells has been mistreated in many ways.
Thanks for your open and honest videos. 👍
Hi, oh! it's really very interesting!!
your cells are now 11 years old! and she don't have
almost no loss of capacity, compared to the standard 160A!
Indeed they had 180 Ah when they were new, the difference is more important, but after 11 years of use, 155 Ah for batteries, validated by the manufacturer at 160Ah, it's impressive!
Did you buy these cells directly from the manufacturer?
Thanks.
I bought really old thundersky, & am pleasantly surprised at the SOH, and good balance
Warm test required I think, even if it’s just one cell to see what difference temperature plays.
On the way 😉
@@OffGridGarageAustralia I think warm test will increase around ~2.5%. I can see this in my car even the battery is not the same. I doubt that this one will behave different.
Very insightful video Andy. Congrats on topping 35,000 subscribers!
My thoughts... For the extra amount you would pay for top tier A+ batteries, you can buy a 2nd (and probably 1/2 of a 3rd) set of storage grade batteries. You're doing it the right way. The capacity, for the money, will always be 2x that of A+ grade batteries.
Thank you, I almost forgot about the 35.000 as a milestone, wow 🤦♂️
Yeah, you can really buy a lot more storage for the same money using these storage grade batteries. I think, they are perfectly fine and I don't mind a bit of extra maintenance and testing. I would have done all the testing anyway just for myself.
Thank you so much for taking this test and showing the results after years of use.
Thanks for testing and commenting why it happens. Good luck with the other tests and videos, always happy to watch them.
I appreciate your transparent and objective approach. It would be interesting to see if this changes during the summer. Although that rate of degradation isn't necessarily alarming given how much time has passed, in my opinion. Still far better than other battery systems I have used.
Edit: imagine getting these results if you had paid that 50-70% premium for the "real" A-grade batteries! Ooof!
I have three of the cells inside the house now and will repeat the capacity test with the same tester I have used inititially with these cells. Results will be in soon...
The voltage slump test correlates well to AH capacity degradation and condition of cell. Just be very careful of external connections resistance causing extra voltage drop. Ideally voltage is measured directly on base of cell terminals.
1 kHz battery impedance meter primarily measures only conductive impedance and does not include the more significant ion transfer impedance. 1 kHz impedance meter is good for checking for delamination. When electrode material delaminates from the aluminum and copper foil the 1kHz impedance meter readings rise.
Ion transfer impedance is the primary degradation as cell ages. It is caused by the growth of the protective solid electrolyte layer increasing resistance to ion migration resulting in greater voltage slump with moderate cell current. The growth of SEI protective layer also consumes some of free lithium reducing the available lithium for cell useable capacity.
Every time a cell is cycled there is some small amount of fracturing of SEI protective layer that is repaired by regrowth on subsequent charge cycles. The regrowth consumes some of available lithium gradually reducing cell capacity and the increase in SEI thickness increases cell total impedance over time.
Capacity loss over time is not the only aging factor. As cell impedance gets greater it limits the practical maximum load current the cell can support.
Very interesting.
It worked ! I discharged to 20 percent today for the first time. I put in two parallel units this morning. The voltage averages and the capacity sum. Now my battery is good for at least 80 % of the battery's amps. The only reason it did not go lower was the inverter determined the battery was 47 v. The lowest cell was still 2.708 volts. I will be building a second 280 a battery and this should give me 680 aH, enough storage for full off grid solar power. It is not to big , still small enough for the panels to charge in a day.
Great testing. Fortunately I started as you with a spread sheet. With top equipment now,, As I get batteries completed I'm going to start a cell swapout/testing. Keeps me busy and batteries in top condition. Older cells will be matched and put together in a battery. No hurry using the ebc-a20. One cell purchase as needed I consider maintenance costs.
I think your results are great considering the COLD temperature , I would expect at least 5 % loss from the cold , more actually . But you made a good point , we need to document the temperature of the cells when taking data points for the spread sheet . Thanks for reminding me.
Yes testing only with the same temp, because these cells perform different under different temps, 25 would be nice, otherwise the test would be useless.
Warm battery test is on the way. With the same tester I used originally.
@@OffGridGarageAustralia Hello Andy, what were your results with warm batteries?
@@nainabla that was in one of the next videos after that.
Excellent tests. Excellent thoughts. Excellent conclusions.
Please keep up the good work.
Thank you, more to come!
You could always sell these batteries as "Used grade B". Lesson here is have a good way to test the batteries you purchase and ALWAYS test capacity when you purchase. I just noticed your hard drive magnets holding your pliers on the bench wall - LOL. Love it. Perhaps, use a heater to warm one battery to "summer time" temps and re-test? I wonder if the capacity would increase. These may be summer-time-only batteries. Thanks for sharing
I probably would not sell them, no. I will continue using them and do more testing over time. They are now a good source of information and can help us better understand the history of these cells and how they will perform over time.
@@OffGridGarageAustralia They could make nice ups batteries no? A UPS only has to run a short time, so capacity is less a worry. :)
How many computers or emergency lights do you have? :P
I really beleive the deviation on your results respect standart conditions is noticeable but not abnormal. 11°C is starting to be quite cool for the batteries. So wirhout another CRAZY week of testing would accept those results as within the normal degradation values. Thank you for such a Crazy testing!! Again...;-)
Thanks Luis. I think the batteries were actually warmer than that. 40A applied for hours is creating quite some heat inside the batteries but I will repeat the test with warm batteries soon.
@@OffGridGarageAustralia Yes, totally. They warm up both 11°C as well as at any other temp you operate them. So there will always be a slight deviation respect ambient temp. We will seen then what comes out on the next test. Thank you again for such a fun!!
Excellent video. You are a goldmine of information!
Please heat up a couple of cells and simulate a “summer” test.
Also, if you can put them back into service, more valuable lessons will come from it.
Thanks for sharing your efforts!!
Yes, two are inside the house now for a few days and I'll test them again then.
I purchased my first 16 a few months after you and I tested every cell. and then purchased 40 more (wanted some spare ones ) and retested every single cell all the old and new cells. Surprisingly the old cells was only down 3 to 6 ah lower than the first test. And was conducted in similar test conditions same temp and same tester.
The newer cells most tested lower than what the old cells was still testing at.
Thanks for sharing. It's very hard to find common sense with these cells. One deliver can be totally different to another one from what people are writing here.
My CALB lifepo are 6 years old in my full time RV compressed. My bank is 8 cells 180 amp/hr ea. for a bank of 360 amp/hr at 13.2 volts. I tested mine 2 months ago. They are always within 10 millivolts at full charge. They have lost 3 percent in 6 years. I love CALB because of the robust case and the large terminal connections. My EVE battery has already stripped out 2 connections and runs almost 80 millivolts delta after only one year, they are compressed BTW.
I agree with your numbers, not bad at all. Given the temps, your use, as well testing at home and the expense of cells. I think your.... right on.
I suspect I live quite close to you (little mountain) and have been following your exploits for a while now. I have been inspired to some extent having filled my shed with 16 x 250watt panels which gives me quite some additional power. I have recently bought a Growatt spf 5000 es and a couple of 6kva 48 volt lifepo4 rack mount batteries from china (currently being shipped). I also have an existing 10kw grid tied system using 2 sma 5k inverters. I am building my off grid system to take some of my electrical load off grid. keep up the great work. my son just ordered a new Tesla which is going to be delivered sept-oct.
Thanks a lot for sharing. Sounds like a great setup you have over there in Little Mountain (3h drive from my place). What brand did you get of these 6kWh batteries?
Looking at the EVE product specifications for the 105Ah battery, shows most test done at 25c +-2.
They also show Discharge-ability at different temperatures.
It might be worth having a look at the battery manufacture specifications when running and comparing performance test.
Enjoy your educational videos Andi.
It's standard practice to use consistent temperatures when testing electrical devices. That temperature is usually 25 degrees C. I look forward to seeing another test with consistent temperatures. I have not experienced any problems with any batteries that I have tested, but I also run a business so I can imagine I get better treatment because of this. I find these videos very interesting, thank you Andy, keep up the good work!
Thank you, Yeah, I have two cells inside the house and will repeat the testing with the original tester.
Thank you Andy!😚 I hope we will can see new test this batteries soon
Thanks for the video. We don't have many people who are actually doing the science, so when we get lucky to have someone like you it's great. As for all the Temperature comments etc. Yes it would have been ideal, maybe you can test a single cell again and see how much it changes.
As for you final question of buying Tier1 battery packs versus buying these Grade B cells, I would have said 6 months ago get the Grade B and save yourself the cash. As of right now my thoughts on this are changing.
Lots of info is coming in saying that there is going to be a massive shortage of batteries in the future and also all these new Technologies like Solid State batteries seem to be in problems again. So right now I would say bite the bullet, spend double the money and get cells that will last 13+ Years with good performance, because that may be how long it takes for this whole thing to settle down and prices to drop down to dirt cheap levels again.
Thanks for another straight forward no deception video. Love your channel. As for the batteries...Reassemble 1.0 use it. The information I personally gained from watching your struggles with 1.0 was priceless. So use it until it no longer functions. The early days of 1.0 was just that the early days. So yes a bit of Tom Foolery from china as buyers were beta testing the battery's. Nothing can be done today about what has happened in the past. Take the knowledge gained and not allow the same things to happen. I would consider these as 265ah batteries and be happy they still work and know I should get another 15 ish years from them. Or you can simply make 12v battery from them and use around your property. But during the summer you will have way to many amps out side and 2.0 will be full. I personally would reassemble with copper bus bars 48v and just add the capacity to 2.0. but knowing I could put in wheelbarrow and move it around the property. Perhaps 1.1 48/12v on a dolly to run the wood chipper? Love your channel have a great day Andy
Gruetoo
Thanks Gruetoo. I will definitely keep using these batteries and 'transform' them into Battery 3.0 soon.
If I charge my other battery fully ins summer time, will have to see. I have also huge loads which currently still run on grid during winter. It will be interesting...
Thanks for the video.
I'm capacity testing lifepo4 batteries everyday and using different testers. These results helps me understand how critical the environment conditions and testers are.
I would take cell #6, warm it up to say 25C and retest it to see how big the temperature effect is. If fact I would likely do several different temperatures to see if I could generate a capacity vs temperature curve. That would likely require building an insulated, heated box for the testing, but the results would be very interesting.
The question that comes to mind; What new storage technology will be available in 2, 3, 5 ,10 years from now. In just a few years the storage capacity of Lifepo4 prismatic cells has gone up leaving the 280ah cells at a reasonable price point compared to 300ah or even 320ah batteries. By next year, or the next I expect 320ah cells will be falling behind whatever is the newest on the market. That would mean the 280ah batteries will even be less in price. So, you could look at what and when do you want to upgrade. Solar panel technology is getting better, BMS' are getting better, and batteries are improving. Build your system to make it easier to upgrade. The 280hr batteries that are in the system now, may be good for 15 years or more even if they are class B cells. But, your system is not a forever system. So, build your system to be ready for the next upgrade. Clear away the cobwebs in 5-6 years and buy 320ah or 400ah or even 500ah batteries.
Thanks. I won't upgrade my system just because there is a new technology coming. I think LiFePO4 is good enough for our solar storage projects, they are safe to use and great in price. I will just keep adding storage as I need it for now and definitely keep testing these cells form Battery1.0. We have now a good start data with them and will see how they perform over time.
In my offer from Basen I got 120ah cells at a better price per capacity than 240 ah cells. I believe smaller cells are actually better for a setup because you have smaller modules and hot swapping is easier and the heat losses per cell (and/or connection) are lower as the connectors are the same.
Redundancy is also better and so on.
Hi Andy...mmmm....classic problem....I have same with my cell N.7 a N.13 same... 200A cells
The cells no lost capacity...they Never had,since you bought them!...
This is a classic problem when order online!!
I appreciate what you doing with some online sellers,now,asking to test and macth cells before delivery.
Other big problem is :
when you buy the battery,if something no good,is not easy to ship back to China,because shipping cost are very hight ,
when you send back goods,but when you buy goods,shipping cost are very cheap!
This is what online seller knows very well!
Baba should change policy and make refund goods shipping costs cheap as buy ones....
Yep, it's all a bit of a risky game. We will see how these cells are performing in the future. I'll keep track of it in the spreadsheet...
Off topic but since this is your latest post, you may read this:-
I have followed your UA-cam channel with interest. I have always wondered about using lower charge voltages to reduce battery stress. But also wonder about using the Equalisation setting to bring the battery back up to 3.6V/cell every 40 or 50 days so as to top balance the battery every so often.
You can also parallel small cells directly with the lower capacity large cell(s). Just use the same chemistry (ensure the voltage is safe in the same range as the pack cells) and realize it may not support the same max current during charge or discharge as the big cell. For example, you might pick up a 10Ah cylindrical cell and parallel it with your 255Ah cell and now you have functionally a 265Ah cell.
This..
I would not recommend this at all. There is no current limiter in between these very different cells. Not a good idea.
@@OffGridGarageAustralia bit if same chemistry and assuming when assembled they are balanced they will simply act as one larger cell... Can't see a problem. Could put a fuse in with smaller cell to protect wiring. This will mean your whole pack is now as small as the next smallest cell.
@@jasondevine6014 Yeah, hmmm. OK, a fuse could work actually...
OK, you try it and let me know 😂
@@OffGridGarageAustralia same state of charge, there will only be a fraction of the normal pack current between them. Fuse them if you like.
It would be interesting to:
1) test the remaining batteries
2) have them join the "new" ones, and be put in production again
3) test these batteries once per year
This would give us all some solid scientific data.
If you buy a second of these 40A testers, you can halve your time on testing these cells. And if then one of them dies, and is not repairable, the other can still perform the same duty for a while longer. Ensuring consistency for a few years longer.
If you’re only charging with solar is capacity an issue?
Cloudy days it may not 100% charge anyway.
I say run them as hard as you can and it is what it is.
At the 10 year mark either they will be replaced with a different chemistry or priced down to replacement isn’t an issue.
Who knows what the future holds but it is interesting to watch.
You don’t monitor the performance of your car engine or the efficiency of an AC unit year to year so what’s the difference?
Buy it , Use it and be happy.
As far a grade B cells I think they are used cells that still have storage capacity.
They aren’t probably warranty replaced battery’s from ev.
Thank you for your videos sir.
Yeah, I will definitely keep using them and they will be going into our battery 3.0 soon. But I will also keep testing them from time to time to learn and share more about these cells.
I know you don't like the idea of compression, but too bad you don't have another similar group that's been under properly spring-loaded compression this entire time to compare these to!
Good point 👍
Agree
There are several items you might want to check.
You should record battery temp before starting test.
I can freely program the EBC-A40L and also include resting times.
The voltage sag while resting is an indication of age but we would need to start colleting this data and see over time what it tells us.
I have some spare cells lying around and may think about setting up a test environment at some stage. There is just not enough time.
10% capacity loss in 4 years is really good actually. Especially with that many cycles. Speaking for somebody with a bank of AGM batteries that spent their entire life as fully charged standby batteries that got used maybe a few days a year, and are around 50% capacity loss after 8 years with about 1 cycle per year.
Thx so much you‘re so great, everything i ‚ve learned about battery technix in that short time is because of you doing that 🐬
Thanks, Ian. It's my pleasure to share this here on the channel.
12:30 with all the B drama, I will not be buying any more EVE cells in the future.
17:00 a few days ago, I was discussing about temperature with some local users, how it affects LifePo4 cells in general and why we should keep them cool. One particular user was not concerned. He opined that his battery can go up to 70℃ while my EVE can only do 55℃. I honestly could not argue against his claim considering 70℃ is guaranteed by his factory-made-batteries. I could not even claim 45℃ from EVE. Whether 70℃ is guaranteed or not, said person was confident with the factory warranty to abuse his batteries.
Maybe I will stick to buying factory made batteries. more expensive, but carries warranty that is hard to beat.
Just placed another order for a second round of 48 304's yesterday. Coming on the heels of your notice of the new MD30 cells coming out. My supplier at Luan finding out from EVE that they are swamped by a buyer blocking anyone else getting the new cells for the time being. But after sharpening her pencil Amy hooked me up with the cells $500 bucks under the cost of the MD30's after shipping and yada yada yada. Quite happy with that. The cells she's sending me are babies at 2 months old.
Even managed to snag 3 more JKBMS's from JK for the price I paid for 2 last time I ordered. Sheesh, on a roll..... lol
Hey, if I can get 16 years out of them they will probably outlive me. That's a plus in my book!
I really like your videos, they are most useful.
I have put two other comments on here today about the awful batteries I have just received from an Al*Expr*ss seller, but they seem to disappear.
I bought 16 New Grade 'A' batteries, and what has turned up is 16 pieces of very old, discharged (2.8v), bulging cells with corroded terminals.
I would give my left arm for some batteries as good as these!!
Best wishes
It seems like a temp regulated battery box would be a good idea to eliminate that variable.
If you use Tesla's claim of 8% loss in 10 years, that is ~.8% per year. 5% to 8+% loss over 4 yrs seems quite high in comparison. It may be a good idea to test one of the QSO cells at this time to see how much of a loss they are showing vs time.
Thanks for the update & keep up the good work!
Well, I think these cells are just fine. With about 5% degradation in 4 years they fit their specs. I believe, that in a normal solar storage the aging of the cells will kill them before they will be killed because of the cycle counts. But a cell with 80% capacity is still good to use, it just has a lower capacity. During aging the capacity will decrease and the internal resistance will increase. So charging and discharging at a really high amperage will not work as good as with new cells. But when do you really need a very high charge or discharge with about 1C? And if you parallel batteries the need for high current will decrease, so old cells will be usable even longer.
And these cells have been tested now at colder conditions than before, so there will be a capacity loss because of lower temperature. It would be nice to know how much it is. Maybe you can test one of the cells with higher degradation in your house at about 20 °C cell temperature to see how much the different temperature causes.
Thanks Gunther. I have 2 cells in the house now warming up and I will repeat the test with the smaller tester when they have the 25° for a while.
The purpose of so called 'second life' battery is exactly for energy storage, so if batteries are being used in an EV for 15 years, they are still great for storage projects afterwards as you said. Just the overall capacity is lower.
@@OffGridGarageAustralia Make sure that you leave the cell in the warm house quite a bit longer when the outside surface temperature reaches 25°C (to also heat internals of the battery). 1 more day after suface temperature reaches 25°C i would say.
@@drister007 I have them in the 'SFK climate chamber' now. Perfect stable temperature conditions. And I will also test them in this chamber.
Hi,
Well, to be honest, I am surprised they didn't degrade further during this time, they were treated badly with deep discharges to the cut off voltage of 2.5V. I do use industrial grade cells in my setup from Winston Thundersky (1000Ah cells at 1C, quck chargeable at 3C, max. current 10C for 10s what means 10000A, it is a nice little 12V 15kWh battery) and the data sheet gives them 2500 cycles on full discharge (they get damaged when discharged below 2.5V or charged over 4.0V), 5000 cycles at 80%DOD (it is about 2.8V cell voltage), full at 3.65V, regular operating voltage 2.8V to 3.8V.
They deliver at 0.5C charge / discharge current about 1300Ah between 2.8V and 3.65V, they are expensive - like 1$US per Ah per cell, but totally worth it. My bank is in daily use as liveaboards, it has delivered in 4 years about 473000Ah or 6400 kWh, it is cycled daily about 50% - 60% and has still 1200Ah between 3.65V and 2.9V - this is my shut down setting.
LFP cells not only degrade when kept at high voltages, but also when deep discharged. So you are kind of lucky to have lost only 5% of the initial capacity in average.
Thanks for making videos and tests public, that debunk a lot of myths around this exciting technology.
'treaded badly"? 2.5V and also 3.65V is within the specifications when I did the few tests in these regions with the cells. And only the weak cells were going down that far, not all of them. This should have nothing to do with it.
don't throw money on "industrial batteries " buy candy for the baby.
let us not become snobs over a technology that delivers energy.
this should be cheap and exchangeable.
Interesting results Andy. You were new to all this and still trying different things (being a sort of guinea pig for all your viewers) when you first tested the cells. Some of the cells were sitting for two years before they even got sold/used. I wonder what the rate of degradation is for cells in storage vs cells in use...?
In the brief shot of your panels in the yard I noticed that some appear to be poly and some are mono. Have you ever checked the output to see which performs better in your area? You have mentioned that a slightly hazy sky (diffused) seems to give you the best output for the panels on the roof. I remember watching Will Prowse do a test on some 100W panels with partial shading and surprising results. I thought it might be interesting if you tested some of your panels (poly/mono) in the diffused lighting you seem to prefer.
Thanks a lot. Yeah, we have come a long way in the last 2 years and learned a lot about almost all aspects of batteries, solar and everything in between. I think it's great to have this platform here to share the knowledge and findings.
I cannot see a big difference between mono and poly. They have different voltages so I cannot connect them to on one SCC.
So, to be clear here:
Full sunshine in winter and the shading on my roof is the worst situation for the panels with least power output.
Cloudy winter weather is far better and I easily triples my output for that day
Full sunshine in summer is... hallelujah
Cloudy summer weather is better than cloudy winter weather but not as good as sunny summer weather.
But a panel test video is next on the list with some very special panels...
@@OffGridGarageAustralia Thanks for the reply and description of the worst to best solar situation for you with regard to time of year/cloud cover. Are the garage roof panels a mix of poly/mono? I wouldn't expect you to mess with those (they are all set up and working). I just thought the solar fence and others you have laying out in the yard might be fun to test. Will used an MPPT SCC hooked to a 12v LiFePO4 battery at a low SOC and just connected each panel individually. (video is called "Mono vs Poly - Real World Test - Worth the $$?" if you have not seen it) The surprising part to me was that the poly panels ended up outperforming the mono panels in every variation of shading he tested... up to +30% in some cases. From all I read about the mono panels the general opinion was that they were superior in full sun and shading, but in real world testing it didn't work out that way. Maybe under standard test conditions they perform better but in actual usage conditions they don't. Whatever panel testing you have planned I'm sure I will enjoy - looking forward to it.
@@gumpster6 Yeah, I've seen his video.
I have polys on the roof as they all are 60-cell modules. The monos I have are all 72-cell modules and therefore having a higher voltage, so cannot mix them on one SCC.
The pool fence is connected to its own SCC because of that.
@@OffGridGarageAustralia Makes sense - thanks Andy.
Those look like great results to me. Were these cells used in that time, cycled on a daily basis? If you still have 80% capacity after another decade that is absolutely AMAZING VALUE.
Yep agree.
13:35 In the four years it lived for about one year in his solar setup, where his smart shunt registered an equivalent to 75 whole cycles.
Pinch of salt 👍 you don't put a grain of salt on your meal or in a pot 😝
Interesting results though 🤔
Here in the UK, its been 25C+ 🥵
You'll have your summer back soon 🥳
Love your videos, always looks forward to a new vid and i enjoy watching your older vids to 😁
It's like 'without further to do' and 'bended', glad you picked this up 😂
Solar is already producing more power every day now, I can see it on the VRM. It's great.
108 degree's fahrenheit in Fort Worth, TX today. At the end of the day. I think I will buy the less expensive batteries again. Although at 62, I expect my new qso (purchased 11-2-2021) A? 16x304AH EVE may last longer than me. Or not, who knows I could live to 120.
I think I will do the same if I need mole battery capacity.
"The "Infamous" Cell #6..." Running some rough numbers:
- Given your test results Andy, of about 5% degradation in 75 cycles (about 0.07% per cycle) I figure 286 cycles until you hit 20% degradation, or roughly 3.8 times your 1.2 year test, or 4 to 5 year lifespan right?
- Assuming that a a 280ah, 16S pack costs about $2,500 U.S. and lasts for only 300 cycles, that's $8.3 per cycle cost right?
- Divide $8.3 per cycle by 14.3kwh, would be $0.58 cents per 1kwh to store and use free sunlight, is that right or did I miscalculate?
If, however such a pack lasts for 1,000 cycles that drops the storage cost to $0.17 per Kwh, and at 3,000 cycles to $0.05 per Kwh.
Looking at the numbers for a Tesla Power wall warranted for 10 years, at one cycle per day, that's 3600 cycles at 13.5kwh per cycle. at about $11,000 for a 13.5kwh Powerwall that's about $0.20 per kwh storage cost. If the EVE cells can manage 3000 cycles and 10years, then you are way ahead of Tesla for cost effectiveness, at 1,000 cycles maybe equal, and at 300 cycles three times the cost of Tesla.
As my average power cost here in cold, wet and dark Oregon is about $0.18 per kwh considering the investment cost, it's more cost effective for me to buy power, or use solar net metering and no storage.
If my figures are correct, then getting real life cycle life degradation data could be useful, Maybe put an automotive grade and reject grade cell in a test bench and cycle them three times a day for 100 days and look for a result?
Considering the cost of cell degradation, with current battery storage chemistry, perhaps compressed hydrogen generation and storage and fuel cells could make sense, and why the rush for solid state battery solutions?
We know that you know that we know that we want to test all the batteries now. :p
Argh... that would be boring. Let's test the whole battery instead.
Gute Arbeit 👍 9% Verlust ist schon heftig 🙈
My 14 kw Chevy volt battery is 8 years in solar off grid and bought on eBay used still has 11 kw usable power and the cells are still balanced
Thanks for these videos. I was wondering if the 40A tester in this video could also serve a a charger for initial cell top balancing, and then for 48v pack charging if needed? If not, do you have a recommendation for a 48v lifepo charger? Thanks!
I kept getting distracted while watching this video I might have missed but did you check the internal resistance more recently or in the spreadsheet are the internal resistance values from when it was first delivered?
Thank you for the video!
My pleasure!
Let’s take a step back here to lead acid days 🤔 5% average degradation in 4 years don’t sound too bad to me
You're right.
Another great video Andy. I have one cell in my diy battery pack that acts like your cell 6. I added a 8 ah headway cell in parallel with the low capacity cell. This adds 8 ah to that cell which stays closer to the capacity of the rest of the pack. I would like to see you try this with cell 6 and see if that makes a difference.
Be very very careful with that. You could have a very high current from the large capacity cell to your much smaller 8ah cell and nothing will limit it.
People have suggested this to me but I think it is unsafe.
@@OffGridGarageAustralia I though you did something similar with a low ah battery connected in parallel to a higher ah battery? So why wouldn't a low ah cell in parallel with a higher ah cell work? The voltage between the two parallel cells are equal.
@@douglasmarquis3446 Nah, this was just for testing to see what happens and I did this with a 4s config in parallel and a BMS for each battery. That was the 4s 304Ah in parallel with the 4s 5Ah PALO cells in parallel.
@@OffGridGarageAustralia But that would only be when you first connect them if there was a significant voltage delta between them, true? So as long as you make sure they're very close in voltage before connecting them, it shouldn't be a problem. Once they're connected and equalize to the same voltage, that problem is gone forever, I would think.
Hi Andy! and thanks again for this video...
And this one is even more interesting!!
You must have asked yourself the question? what were your battery used for, for 2 years before you bought them??!!
I think that not only manufacturers resell cells that have not passed the Quality tests, but I also think that they resell cells that have already been used, replaced under warranty by them, in uses for EV (car, bus etc ...) they have very important contracts, with car manufacturers, and replace battery packs under warranty, this is part of the terms and conditions of sale of their cells.
If we look, more positively, for our use in solar system, these cells remain I think acceptable.
One thing worries me a bit is that often the battery start to show signs of weakness (reduced capacity)
often gets bigger and faster...??
The solution is I think, just replace the weak cells, and continue to use the pack normally.
Andy, the more I watch your videos, especially the latest ones about cells, the more I learn about the longevity qualities of cells, I really think that if we want top cells, we have to buy them from the manufacturer. they are expensive but certainly
that for a long use, without worries, it is the solution.
I no longer have any confidence in these resellers, who only lie. (now we know what we are buying?!! and it's a lottery!)
These cells were new when I got them as far as I can tell. Otherwise the terminals would have some sort of marks, scratches or sign of a busbar being connected. But these ones did not have a single scratch or mark.
@@OffGridGarageAustralia Ok Andy, but I think they are smart enough, to hide anything.. Originally the terminals are not drilled or threaded, (because I think they are welded into the EV packs) it's easy for them to resurface the terminal, make the thread hole, and a new packaging, the blue insulation and the black top cover..
And there! apparently it's a new cell😜 (they buy laser welding machines to weld new terminals.. It's child's play for them to make a cell look new! 😁
I have bought 2 Narada 48NPFC50 back in Nov 2021 & another 2 Dec 2021. Both sets have different voltage profile and first set don't have manual circuit breaker.
So the first set is always discharge faster and went into protection mode then the second sets. Out of no choice, I installed a smart timer for the first set of batteries. They were cut out of the system in the middle of the night then back on early in the morning. The second set of batteries works thru the night.
This might be the solution for battery that are parallel linked.
Thanks for sharing, Michael. That is very interesting as some people here leave comments saying the server rack batteries are the solution to the DIY stuff we're doing. I was always very sceptic about that statement as you never know what batteries are in the metal enclosures either.
So are yours not in parallel but different systems?
@@OffGridGarageAustralia All 4 batteries are parallel together. It's clear the first 2 sets are the older version as they don't have manual cut off switch.
I have been running them down to 48v. Battery manual says it can be run till 42v. Only one of the older sets keeps going into protection but it always comes back after reset. The batteries seller said only run till 50v. But at 50v cut out settings on grid tie inverter, sometimes that batteries still went into protection. The other one same model it's just low voltage. They newer model sets was showing 2 green LEDs out of 4. I am suspecting grid tie measurements inaccurate + power draw and both set batteries have different voltage profile + capacity.
@@michaelseah9617 Do you have access to the BMS settings at all and can actually see single cell voltages?
@@OffGridGarageAustralia There is RS232 port on the batteries. In the manual it says need to make the wire. Plus needs to get the software from Narada.
I think they’ve done ok Andy. I see a big difference in capacity with temperature so in my opinion this is quite acceptable. Put them back in the tub with regular BMS + a Neeeeeee balancer or JK and call it good. Charge them to 80% and they are a good standby for when SHTF.
I think as well they're still good and we will re-use them soon in our Battery3.0 project.
@@OffGridGarageAustralia Hi Andy, you've already mentioned 'our Battery3.0 project' a few times in your comments and videos. It makes us very curious. When can you give us a sneak peek of your new plans? Kind regards.
Hello.
First of all I congratulate you and thank you for your videos which taught me a lot of things.
However a question remains in my head: is a communication mandatory between the BMS and the inverter/charger?
Please accept my greetings.
Bonjour ANDY, après les vacances et des occupations personnels je suis en libre pour continuer l'aventure avec OFF GRID GARAGE 😉, je reprends les vidéo par ordre de publication. Belle analyse pour la batterie 1.0 👍
I am about to install LTO cells in my car, for a starter battery, so I am super curious if they will last as well as they allegedly should, when used hard. 10c discharge (for 2 seconds max), some heat in an engine bay (living in QLD). I really hope LTO as a chemistry is the holy grail of "forever" batteries..
LTO is def a better chemistry for the hot and cold cycles of a vehicle. I use lifepo4 due to the voltage difference and they've held up fine for a couple yrs but I have to watch the temps
How do you control the current from your car's gen to the LTOs?
Hi Andy, I don't see 5% over four years I see 5% over two years. The period before you purchased them was storage mode typically 20-50% and therefore only a few cycles. The temp difference is a big factor in the results so not so bad. André in Sydney
But we don't know how they have been stored in these two years... And even leaving them at 50-60%SOC will degrade them over time.
Please;)
put them in production with the rest and continue to do these tests every year ... but in the summer :)
I will with battery 3.0. I have to cells inside the house now warming up so I can do another test with them in warmer conditions.
If you freeze in the workshop I have an idea. A solar panel gets hot, make a box behind the solar panel and circulate the air from the workshop into the box and behind the solar panel and out into the workshop again. Great work with the batteries. Best regards From Denmark.
If I would have hot solar panels, I would have power to have a heater on. As you may know, I'm in full shade in winter though 😊
Second.
Just completed the capacity test of the second cell of my "brand new grade-a" cells from Basen. Ordered end of April 2022, received this week. First cell 289Ah, second cell 278.8Ah. One out of two already below 280Ah. Tested at 20°C. And the ZKE Tester does only test at 0.14C and not 0.5C as per spec...
Also, one cell was delivered with only 2.7Ah capacity left (2,8V). At least the only optical anomalies are very small dents and small pucture foil damage. All cells are from 2022 except one from 28th Dec. 2021.
Very brand new grade-a.
Update: Third cell 280.5Ah. Just passed requirements.
Maybe they could be matched to groups of 4 for 12v set ups. Or possibly groups of 8 for 24v.
Just a thought.
I have a lot of 12V batteries already and these ones will go in the battery 3.0 setup soon. Together with some others...
Hello.
As an example, can you calculate the amortization period of the purchase cost of a current Lifepo4 prismatic cell with the current electricity unit (kW) price? After how many cycles can it hold as much energy as its purchase price?
Andy, have you used the app on the batteries in the shelf yet to see if you have been ripped off with them too?
No, I haven't checked them yet. Have to take off the glass, too much work, haha.
Yah, I'll have to do it at some stage.
Having the same experience, building 48v systems with 20 cells. The 4 extra cells are in parallel with cells 1,8,9,16. When a cell goes wonky, over charge cutoff6or under charge cut off, it is swapped out with a spare cell.
Oh, no, that would be really bad and far too much effort.
I haven’t seen the video where you must have found out the cells were already 2 years old. How did you find this out? Also if you are concerned that these are not grade A cells, have you removed the black covering on the top of a cell to see if there is another QR code on? I will be interested because I’ve just bought 16 x 230ah cells from Docan Technologies as grade A and they have said they are brand new unused. These also have an intact QR code on and the black cover. Great channel by the way, learning bits from all over about battery building.
Can u send a link to that charger
The tester is on my website. It's the EBC-A40L: off-grid-garage.com/measurement-tools-and-analisers/
For people like you with multiple strings surely you could "just" capacity test all of them and reshuffle them into "the big battery", "the medium battery" and "the little battery (that couldn't)". It would only take a couple of months and after that plus a lot of faffing around you'd have slightly more usable capacity from your three strings. Totally worth the hundsreds of hours work!
Love the sarcasm. LOL
You must have the same problems as I see with my batteries and talk from experience.
Can you show us how to use this ZKE Tech contraption to do an internal resistance test?
Hi, Endy! What is the condition of your battery 1.0 cells now? It would be great, if you make new video with new capacity test of that cells. Maybe, degradation is at around 10%?
Gut sehr gut 👍🤗 danke fürs Video
How often do you change jumping on and off cells. From looking over hundreds of videos cells 1 and 16 are taking every surge in/out for months on end?
Hallo Landsmann , klasse Kanal , Hut ab ‼
Hello Mr.
I have one question.
Rept or eve battery cells?
Thanks
The biggest issue you have is that the cells are not closely matched which results in more maintenance. I changed mine out for matched and batched. With a 16 cell system everything balanced to 10mv without all the maintenance.
Well, once they are top balanced, it should be fine and the BMS and balancer should take care of the rest. The lowest capacity cell still determines the overall capacity of the whole battery of course. But, hey, for that price... 🤷♂️
It not just the capacity. If the cells are not well matched in the first place they will drift even after top balance. At least that has been my experience.
So would I be right in saying it would have been better to cycle these more maybe 700 cycles rather than 75 over the 2 years?
I have been watching your videos over the last 2 months and getting quite excited to start my own system so would just like to say thankyou.
Thanks Helen. If you cycle them 700 times you will see even more degradation. On the other hand you putting them to a good use and if you charge them from solar, you would have saved a lot of energy. Charging and discharging them twice is not easy though but could work for certain applications and setups.
Those batteries are fine! Put them back in service and flog them!
Battery 3.0 💪
generally LiFe batteries are rated by manufacturers to be usable down to 0degC, however recommended between 15 to 35degC, colder temperatures will decrease usable capacity, and risk lithium plating of the anode with higher discharge rates at lower end temperatures (permanant damage), in short, the 6-8% drop in capacity at10degC over the rating (likely speced at 25degC) should be expected. try re-test at 25degC?
I've got two cells in the house now to warm them up and re-test them.
I wonder If it is right to call it degredation considering that the 280 Ah you use as beginning is right or not cause such battery cell that did not met the EVE Automotive Grade might have been sold due to too low capacity at 279 Ah.
I have only checked the equation for that 266,x Ah cell which equaled 95,1% capacity compared to 280 Ah and 4,9% loss in just 2,33 years of use.
Wouldn't it be better to compare the 266,x with your initial capacity result from 2020?
That ist real degredation during your usage and you do not know how badly these cells were used in those 2 years before.
Or did you test that 266,x Ah battery back then accidantly with 280 Ah?
Sorry, i'm only using my phone and can Not really read or access your spreadsheet to cross check that formula.
I also suggest to keep an eye of the ambient temperature cause from 25°C to 0°C a lfp cell will loose roughly 20% . 6° less than first Test in Sunny australian summer and you might get 5% less . Same as range of ev drops by ambient temp. in Winter and can double in summer.
Too few yt measure room temperature curve during discharging even though everybody should now that above 25° C the capacity stays the same
It is time to emphasize it again to avoid false conclusions. I had seen such drops die to temperature.
Check the specs sheet curves EVE had released back then. Might help to get it right, measuring at Dame season and similiar temperature.
Have you made a follow up study up to this calender aging study? I,m busy doing this myself - seems like about 3-4% per annum
did you use compression on them?
Can you retest one of yours cells at a higher temperature? That would shed some light on the effect of the temperature.
Yes, I have two cells inside the house now and will retest with the same A10 /A20tester as initially.
question is how many cycles have they run in total? ive extensively used lifepo4 cells, especially 18650 cells, their promissed life span of 10 years seems over estimated, ive seen around 5-6 years of life from them. i didnt count cycles on them, as that would be hard but they were charged with around 0.25 C maximally. i think 1000 cycles down to 60% capacity seems to be the standard from my experience.
Thanks for sharing. What voltages have you set for these cells for charging and discharging?
@@OffGridGarageAustralia discharge down to 3V, and charge up to 3.6V its a solar product so it uses the sun, taking minimally 4 hours to fully charge, but usually more, so 0.25C or less as the charge current. whe've made millions of these, and i can tell you the claim of 10 years or 2000 cycles i think cannot be had, but its directly proportional to C-rates, the faster you charge or discharge, the lower the cycle life of the cell. the numbers given by manufacturers are theroretical calculations based on accellerated aging tests, where obviously they try to make things look as rosy as they can.
Hola: mi mas sincera enhorabuena por estas páginas tan interesantes y de las cuales he aprendido mucho; GRACIAS y Enhorabuena. Ahora si me permite un comentario relativo a este problema de los contactos. Permítame que le sugiera si la pasta anti oxido de aluminio es conductora o realmente si Usted mete la puntas de su polímetro en el tarro de la pasta anti óxido, este le indica falta de continuidad o por el contrario le indica como buen conductor. Si el polímetro le marca que esta pasta es aislante, ya sabe, es mala, no la use. Quizás lijando y después usar pasta de aluminio conductora y antitérmica, la misma que se usa para los procesadores del ordenador, quizás funcione. Perdone intromisión. Un saludo desde España.
This is the reason why i measured all of my 48 cells ahead, to put the closest ones together. And 5 of them reached the claimed 304 Ah. So i would not say there has been much improvement...
great video. 👍
Thank you 👍
How have the cells been used over the years as well? Cycled daily as part of your power system? or just for playing with cycled every few months?
Is there a possibility to assemble a battery of higher capacity cells and a battery of lower capacities regardless of age?
Which cell is better EVE or NARADA
The problem you have is that different testers were used before. Even if you used different wires in the test in the past that would affect your Ah readings. You could average the cells and do a 4s4p system as a backup for priority loads.
I know, different tester, different temperature and even different amps to test, can already make a difference. How much is just speculation though.
Sir if I have a 16s3p 280ah eve battery what compatible active balancer? How many ampere active balancer?
What BMS do you use, is that not sufficient?
With some A Grade CALB cells now over 10 years old I can confirm that capacity loss does stabilise and that to minimise capacity loss store at around 30% SOC where natural discharge is very very low.
Thank you for sharing.
So we should buy lithium or leadacid which one is best?
Wow, I wonder what happened to those low cells? Initial manufacturing and not properly sorted to get you a matched set? Some individual abuse while in your care?
I have only ever used these cells as a whole battery in a 16S configuration. I did some initial testing with cells 1-4 though but these are the better ones in the pack now 😊