I am building my own off grid solar system and have been watching youtude videos now for about a year, which sort of makes me an expert viewer, you and two other individuals produce some of the best video, steady camera, good explanation, and no "Ahs" every second word, thanks for your hard work trying to help us new users to solar....it is much appreciated
@@saadomar1101 If they're charged to 4v per cell and discharged to 3.1v per cell then the maximum cycles will nearly double. Charging them to 4.2v and discharging them lower than 3v is the standard. The last 0.2v is about 200mah, or lower depending on the cell's max capacity. So not much trade off to gain a lot more cycles.
Hi, been watching your channel from the UK for ages and to start with had no idea about batteries/solar but after a while of watching I now have a basic grasp of the theory.. Many thanks and hope you continue to post vlogs to us newbies😊
Man this is awesome !! Discovered these 18650 by accident recently and for some strange reason i am following online and buying tons of gadgets, chargers, cables, multimeter, etc, etc, building a battery pack myself, i first got cells from my old Thinkpad, testing them was fun and i fell into the rabbit hole so to speak, i am autistic and this sort of thing is right up my street, always enjoyed having collections of batteries and chargers but never had a need for 18650 until now, its so addictive !! great video thanks.
Being able to make your own power supply for different voltage/current levels today is more important than ever!!When you have your own electrical power at any level whenever and whereever that can be applied as quickly, safely is "SUCH a powerful tool to have!!!!!!!!!!!!!!!!!!!!!!!!!!
It is totally freaking awesome, its the best tool I have ever owned. Its available from Keith as David says, but if you are based in europe just go to www.keenlab.de/index.php/product/kweld-complete-kit/
This is by no means my favorite build I've seen you do but it gave me the gumption to try an 18650 build. Battery hookup posted some used salvage valence batteries which as you probably know are full of 1300mah lifemgpo4 18650 cells. I got 3 batteries in the pack but there's bad cells in the bunch, so I'm hoping to get 200 good ones out of the 300 cells. Not the most energy dense chemistry ever but tolerant, reliable and long life. We'll see if that holds up after they got used and abused in their past life. Thanks for the inspiration.
Great video. A couple of things I noticed. You mentioned that you set up the jst connectors to hook up your little gizmo to see how your batteries are doing....in reality it will only show you how each 'group' of 12 batteries, set up in parallel, are doing. It will not tell you if an individual cell is having issues. This will initially be masked by having the others cover for it, forcing them to work harder and weakening them as well. Which can lead to issues down the road. Unless you check them individually, you can only check up on the group as a whole. The 2nd thing you mentioned is that you don't have to make all your batteries at the same time, that you can add to them as you go along. This might not be a good idea unless you can match their capacity. For the same reason as above, if the first battery you put together was in good shape, a few months later, after alot of use, it might have lost some of its capacity. If you then put a new battery together and add it to it, it will potentially be at a different (higher) capacity. This will lead to it working harder to cover for the older battery which will lead to it's losing capacity earlier. The stress could also cause the individual batteries to get out of balance and because you can't check them individually... You ideally want to match battery amperage and capacity before pairing them.
Probably the nicest Electric Bike DIY battery pack I've ever seen, very nice work! Making one immediately for my bike, probably use a plastic ammo can and put it in a backpack with a pigtail quick connect for security and stealth
Careful - 18650(s) are addictive... I started with 96 of them and 2 years later they grew to 1,000(s) :) You may have done this but you didn't mention it, so just in case, let me suggest that one should match the ah(s) in each parallel row so they all have aproximately the same ah. For example, 12 * 2300ah cells in 1 parallel row is 27,600ah so you you want all the other parallel rows to have aprox 27,600ah total (+ / - 5'ish%). The better they are matched, the easier they will stay in balance as the battery is charged/discharged.
I can see how important this is Kenneth, I guess it matters more the more cells you have in P? Anyway, I'm considering making my next build with those 26650 LiFePo4 for my workshop powerwall (3kwh) The problem is I can't find a charger/discharger for those that can do the Milli-ah calculation. I don't think my Xtar Dragon 4 thingy can do that chemistry, even though its a GREAT charger.
I used an ammo can to make a self contained tester for checking trailer lights and trailer brakes. It only had to be 12 volt to operate the lights or brakes. I use it to test to trouble shoot if there is a problem or after doing a repair on any of these circuits. To charge it, I added a 12 volt power socket on the outside that I can connect to the 12 volt socket on my vehicle while I am driving. The socket on the ammo can can also be used to operate anything that can be plugged into the 12 accessory socket. It has the digital display that shows the voltage and also shows the current amp usage of whatever it is operating. The amp readout is great for testing the trailer brakes. By looking at the amp readout, you can tell if one of the brake electromagnets is bad or not.
Sure! It’s easy to teach something if the audience already knows all your ackronyms! That’s like teaching into the mirror. Only needs one person, no empathy and no thinking. Bye.
Thanks for the video, been looking into building a DIY eBike and building my own battery pack for that so I have been watching just about everything I can using 18650 cells haha.
That's exactly what I use except with a IEC/UPS kettle connection,I can't guarantee that mine are water proof but it's an innie connection so water will have trouble getting in
Thanks David, please do another video of this kind,respect from Kenya! Edit,am addicted to 1860 battery build but nowhere to be found in this part of the world
@@DavidPozEnergy No, I think you should give it to me to make a video on 😉 Seriously though, leave that to the manufacturer. I was building one of my own, but that one looks so good I think I'll buy one. Who did you say made it?
You did not current test the battery. Thus you couldl have a unbalanced bank of batteries after a few use (think of one bad battery). This could lead to one of your banks becoming drained and reversed charged. That could lead to one large fire. does the bsm have a low voltage bank alarm or are the tabs also a fuse? What was this design based on?
Dave, loved the video. I live in Woonsocket and not far from 18650 Heat Shrink & Cell in Lincoln. Sounds like you are not too far away either. Would love to grab a coffee sometime. I have a slide in truck camper that I want to put 200-300 watt panels on and a couple of Lifepo4 batteries so I can boondock for a week or two off grid without starting the generator.
I've also some bad luck with the red Sanyo sells, they are really hot when i use them and i had some old ones in the past that had leaked, no other brand that i've personally seen had done that
That's a great little project! People will be able to follow along. Hey, on your miter saw, have you considered powering it with DC? It's probably got a "universal" motor that will run on either DC or AC. You'd need a 120 V pack, but you wouldn't need an inverter. Keep the projects coming!
Brilliantly designed pack! I've would add third wire to buss bars. Do not leave these voltage monitors / ballancers unattended in the pack. From what I remembered they drow their supply only from one cell in the pack. If the pack is left for long time without charging, this cell will be drained. Keep the good work
Great build. I have 2 packs almost identical to yours. I use them to power my tandem trike. I used Samsung CGR18650DA cells and can pull 40A without any problems. I wish my packs looked as good as yours. Thanks for a good video.
what is advantage of all this work to spot weld 168 cells together vs buying the big flat battery packs which are high amps/capacity and only having to solder in a dozen spots?
For padding, I would suggest either a 5mm craft foam or the anti-fatigue mat available from Home Depot. It will not likely break down, unlike bubble wrap, and can be better cut to shape.
Have you considered the Headway 38120 LiFePo4 batteries from batteryhookup for your Mitersaw? Maybe only in 24v for less weight. They are huge and their discharge rate is very high.
What happens if a battery goes bad and shorts? No individual battery fuses? Looks like maybe those little rings that are spot welded have a smaller tab connecting to the rest that could burn off perhaps?
Nice I was waiting for you to start with 18650 cells. And yes I want to see a high amp 18650 cell pack or 21700 cells. Keep up the good work David. Greetings from Spain :)
Hey Dave if you see this. You have to go to harbor freight and get a pair of icon flush cut s. There expensive at $40 but lifetime warranty. I use them to cut the nickel off the cells. I did over 500 cells with my set. And they still cut like new.
Hi Dave, just watched this video of yours and liked it a lot. I was a little concerned when I saw you wrap that tape and then the shrink wrap around the whole bundle. I know it looked nice and neat but I was concerned about ventilation and air cooling. At the end you mentioned removing the gasket, and I assume that was what that was for, but with all the tape and wrap, there is no way you can get any air cooling. Just my thoughts. Thanks for the videos. M.
Heat dissipation is a concern for heavy loads or fast charges. Author mentions limiting the max amps for that reason. 20A max / 12P ~ 1.6A per 14S group, should not generate too much heat from 2.2Ah rated cells. For protection a BMS with thermal shutoff function could be used with sensors distributed within the block.
Hi David, once again awesome video! A few things, you need to sort the cells into banks capacity wise , the reason being when drawing current from the pack if one P has a lower capacity it will drain faster than the others, thereby causing the pack to discharge faster than it otherwise would have. There is an online cell logger I think on battery hookups site? Not completely sure on that one so don't quote me there, Average Joe uses it when building his batteries to closely balance his P's capacity wise. The other thing I would have done before heat-shrinking the battery would have been to charge it up and do a full few cycles drawing enough current so that you could monitor the cells with a thermometer or if you have one an IR thermometer so that you could see if there were any problematic cells before sealing everything up. It would suck big time to have to tear it all down just because of three or four cells not wanting to play nicely together. There are a few downsides to using recycled cells, BUT, it sure beats the crap out of a LA battery, AND! You DIYed IT! Once again, Awesome build.
I agree. The website is repackr. You put in all the cell capacities and it organizes them for you. I wanted to do this, but couldn't. The tester I used was way out of whack. I couldn't trust any of the numbers it was giving me. If I had used some Opus testers, then I could have trusted the numbers and I would have used repackr. that was my original intent. The only good thing about the tester I used was that it charged and discharged the cells heavily so I was able to see if there were any "heaters". (none). I plan to do a follow up video with some testing. I'll let you in on it. I discharged the whole thing in under 2 hours, (high amps) and we did not exceed the cells data sheet for maximum temperature.
I would drill some holes in the ammo can if you're going to keep the lid on. If the cells experience thermal runaway the extreme pressure inside a sealed metal container could be dangerous.
Decent, except for the low amperage. Much of the fun of using that size battery is being able to draw hundreds of amps out of them when needed. I use only 6 of the 18650s in a portable "juicer" for my smartphone and it works well. I just used a "hodge podge" of batteries, some new, some used, I didn't care. It can charge my smartphone 3 times from 0 to 100% before it needs to be charged too.
This would be a nice way too power up your RV camper. Small, and can be daisy chained in series for more amp hours. Imagine 6bof these in a camper, with solar panels on the roof, and a nice inverter. I imagine one could get several days off a bank of 6 of these.
David there is a plastic sheet called Coroplast that is like plastic cardboard. It is commonly used to make signs and you can get it for free from some gas stations when they throw their signs away. I prefer to purchase 4X8 sheets and cut it up to make my dividers and covers. I use Kaptom tape where appropriate but only use packing tape on the Coroplast because the Coroplast in not high temp so why use high temp tape. Your plastic bottle is also not high temp but the Coroplast is much easier to use. Coroplast comes in different thicknesses the 4mil is the easiest to find and is what most gas station signs are made of. I much prefer the 2mil type but you will need to go to sign store to buy it!
Thanks for sharing David. I was wondering if you would mind giving me the best lay out and component values that I would need in order to build a 220 to 240 volt 5 kilowatt off grid solar system? Themis.
For the first time I get how fuse strip works out... If a battery shorts, the fuse melts and disconnects battery.... Why did I have such a hard time sorting that out...
With 12 batteries in series, with 1 amp fuses. Do you not have ~12-15A discharge before your fuses blow? ... Even before the midnight solar breaker trips?
I have 12 cells in parallel. The nickel fuse strip is good for 3 amps continuous. And the cells are rated for 3 amp continuous discharge. So the build can handle 3a times 12 cells = 36 amps. The circuit breaker is 20 amps so it will pop before the cell level fuses burn out.
@@DavidPozEnergy so, what you are saying, with the nickle strips, in this case, you do not need the glass fuses which hbpowerwall adds to all the packs?
Hello, do u have a project that would produce a pack that could be carried in a back pack to power corded tools like a lawn mover, a weed eater or a leaf blower
Yes. Here is the video on the battery I recommend for that: ua-cam.com/video/8nn7EWmLs1k/v-deo.html And here is the video on the back pack build: ua-cam.com/video/7kYrtXuIY-E/v-deo.html
Thanks for sharing. Would it be too much trouble for you to give me the best lay out system and values of the components I would need to build a 240 volt 5 kilowatt off grid solar system. Thanks
I don't know which is best, crimp only, or crimp and solder. But I do know that no matter which way I do it, there will be people telling me to do it the other way. LOL. When I made my video on LTO I crimped and soldered and received quite a bit of negative feedback for that.
DavidPoz Haha, I made a video with crimp and solder and received similar feedback. One of my electrical engineering profs justified the crimp and solder method stating that the solder wetting the copper prevents copper oxide from forming at the junction. Copper oxide is significantly less conducive than copper metal. Additionally the solder helps prevent the connection from wiggling loose as the crushed copper deforms over time from the pressure causing the connection to loosen up. Just my 0.02- I’ve never had trouble with crimp and solder and have seen crimp only fail many times before (mostly due to bad crimp jobs though).
have you looked at incorporating super caps into builds? could they be slowish charged with batteries for short bursts of high power, such as starting the miter saw?
I didn't hear you mention that the tape is kapton (and why), not just a cheap yellow packing tape. My first question was, what do you need a 48v battery pack for? (wait til the end) You did vaguely mention "add to your system" and "my tower of power".
It would be cool to make a can for conversion. Mainly a 48 to 12 DC to DC converter. I am thinking about making something similar for Ham Radio. How is the heat? I was thinking about liquid cooking it. For the surge of the saw, a large cap could help out.
If your radio is 12v, then you can modify the design to make a 12v battery. Then no converter is needed. But, there are lots of 12v lifepo4 batteries on the market, so you have choices if you want to buy one.
So at the end you gave us an application where this setup does NOT work (your mitre saw) .. but what would some applications be where this WOULD be useful?
The spot welder is called the "Kweld". It is sold by Keith, owner/operator of "18650ed" in Rhode Island. You can call/e-mail, or message him in facebook to place an order. I'm not affiliated with his company. I bought mine from him at full price and it works great. I wish Keith had a way to just buy it online, but for now at least, you have to e-mail him. 18650shrinkandcellholders.com/kweld/ I bought the cell holders from him too.
you could use them for a Golf Cart 48v times 4 of them would give you over 5 kwh . You would need to put at least a 400 watt controller I think. If you went easy you could probably go 3 rounds of golf before a re-charge.
If There was ever a major failure and the fuses had to blow. I'm not sure that plastic bottle would insulate against short circuits. I just watched the video that average Joe done with his thermal cam. Showing the fuses blowing. I would love to see that test. Love your vids mate
Do you have any suggestions of something thin, non-conductive, with a higher temperature rating? I think 2-liter bottles are PET plastic, which is like 500°F. I think that's higher than the plastic in heat shrink, but I'm no engineer. There is also 2 layers of tape in the sandwich. I saw Average Joes video. It was great.
Yes, but it would be much larger. I built a 12v version, but you would still need 3 of them to handle a 3000w load. ua-cam.com/video/6Ai5IRQbLcc/v-deo.html
It seems like you have a great workshop and lots of tools. Were you building a different kind of projects before you got into the power walls and solar?
Great build. Looks as good as factory made. Only concern I might have is with the ammo can is if there is any interior heat build up. How would you know before a cell goes thermal runaway? The can being fully enclosed would also not allow much ventilation of the packs. Maybe do a strong load test and show monitored temps at various cells IN the closed can and the outside metal of the can. Maybe the can is an adequate heat sink to air, but does not help if a cell becomes a heater. Great job!
It's always about compromise. You can have wide open cells in the room, but no fire protection. This takes the approach of enclosing the cells to protect the room. The downside is you have to limit the amps to limit the heat buildup. That's why I used a 20 amp circuit breaker. The cells could do twice that. I have been doing a series of tests on it at different amps and measuring the heat buildup. It will be in a future video.
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
I am building my own off grid solar system and have been watching youtude videos now for about a year, which sort of makes me an expert viewer, you and two other individuals produce some of the best video, steady camera, good explanation, and no "Ahs" every second word, thanks for your hard work trying to help us new users to solar....it is much appreciated
I am wondering if packs like these can be cycled everyday to some percentage (not full) or if they are for backup purposes only,
@@saadomar1101 If they're charged to 4v per cell and discharged to 3.1v per cell then the maximum cycles will nearly double. Charging them to 4.2v and discharging them lower than 3v is the standard. The last 0.2v is about 200mah, or lower depending on the cell's max capacity. So not much trade off to gain a lot more cycles.
Hi, been watching your channel from the UK for ages and to start with had no idea about batteries/solar but after a while of watching I now have a basic grasp of the theory..
Many thanks and hope you continue to post vlogs to us newbies😊
Glad to help. I'm new to these small cells (18650). This was my first build with them.
Man this is awesome !! Discovered these 18650 by accident recently and for some strange reason i am following online and buying tons of gadgets, chargers, cables, multimeter, etc, etc, building a battery pack myself, i first got cells from my old Thinkpad, testing them was fun and i fell into the rabbit hole so to speak, i am autistic and this sort of thing is right up my street, always enjoyed having collections of batteries and chargers but never had a need for 18650 until now, its so addictive !! great video thanks.
Being able to make your own power supply for different voltage/current levels today is more important than ever!!When you have your own electrical power at any level whenever and whereever that can be applied as quickly, safely is "SUCH a powerful tool to have!!!!!!!!!!!!!!!!!!!!!!!!!!
Thank for sharing and the parts list\costs David. You're getting a lot better at builds...;-) Well Done.
Thanks for watching.
I love that spot welder!
I have been using those modem packs for about 6 years now and have never been disappointed.
i made one of those a few years ago, same ammo can. I used lipos in mine though and glued a 300w inverter to the side :D. Loved the build!
I seem to remember you taking apart Ryobi packs for the Lipo cells. Is that a related build?
@@DavidPozEnergy I used RC lipos in mine.
That coil whine of the spot welder sounds so cool
Your spot welder is the most satisfying sound I've ever heard. It should be the default sound on all computers for "your input was successful".
Great video thanks for your time ser !!!!
That spot welder is amazing
It is totally freaking awesome, its the best tool I have ever owned. Its available from Keith as David says, but if you are based in europe just go to www.keenlab.de/index.php/product/kweld-complete-kit/
Betting this is super doable and easier with prismatic cells as well! Nice video Dave!
I'd love to build it with some prismatic cells.
@@DavidPozEnergy Pretty sure the prismatic cells would cost way more though. You got out pretty cheap on this one!
Very nice neat job. I love that welder you're using.
Nice package David! Great value option too.
Very nice video,good job
Yep I want to see you build it for your chop saw cause I want to do the same thing thanks for the vid
thanks for the great video! i really like the 48v, size, cost, spot weld tech and value of this build.
Thanks for watching.
This is by no means my favorite build I've seen you do but it gave me the gumption to try an 18650 build. Battery hookup posted some used salvage valence batteries which as you probably know are full of 1300mah lifemgpo4 18650 cells. I got 3 batteries in the pack but there's bad cells in the bunch, so I'm hoping to get 200 good ones out of the 300 cells. Not the most energy dense chemistry ever but tolerant, reliable and long life. We'll see if that holds up after they got used and abused in their past life. Thanks for the inspiration.
Great video. A couple of things I noticed. You mentioned that you set up the jst connectors to hook up your little gizmo to see how your batteries are doing....in reality it will only show you how each 'group' of 12 batteries, set up in parallel, are doing. It will not tell you if an individual cell is having issues. This will initially be masked by having the others cover for it, forcing them to work harder and weakening them as well. Which can lead to issues down the road. Unless you check them individually, you can only check up on the group as a whole.
The 2nd thing you mentioned is that you don't have to make all your batteries at the same time, that you can add to them as you go along. This might not be a good idea unless you can match their capacity. For the same reason as above, if the first battery you put together was in good shape, a few months later, after alot of use, it might have lost some of its capacity. If you then put a new battery together and add it to it, it will potentially be at a different (higher) capacity. This will lead to it working harder to cover for the older battery which will lead to it's losing capacity earlier. The stress could also cause the individual batteries to get out of balance and because you can't check them individually...
You ideally want to match battery amperage and capacity before pairing them.
Probably the nicest Electric Bike DIY battery pack I've ever seen, very nice work! Making one immediately for my bike, probably use a plastic ammo can and put it in a backpack with a pigtail quick connect for security and stealth
That will be great for an ebike.
Nice job David!!
cool little monitors!! thanks for the education
Pretty clean build. I guess I would hard mount that breaker to the lid of side of the box but that is just me.
Careful - 18650(s) are addictive... I started with 96 of them and 2 years later they grew to 1,000(s) :) You may have done this but you didn't mention it, so just in case, let me suggest that one should match the ah(s) in each parallel row so they all have aproximately the same ah. For example, 12 * 2300ah cells in 1 parallel row is 27,600ah so you you want all the other parallel rows to have aprox 27,600ah total (+ / - 5'ish%). The better they are matched, the easier they will stay in balance as the battery is charged/discharged.
LOL. I can see how addicting they are. Very satisfying.
yes same story here. now I have over 4200 cells 14s300p
I can see how important this is Kenneth, I guess it matters more the more cells you have in P?
Anyway, I'm considering making my next build with those 26650 LiFePo4 for my workshop powerwall (3kwh) The problem is I can't find a charger/discharger for those that can do the Milli-ah calculation. I don't think my Xtar Dragon 4 thingy can do that chemistry, even though its a GREAT charger.
Something I wish I was good at! I love building car systems and E bikes so I can see having a use for these!
I used an ammo can to make a self contained tester for checking trailer lights and trailer brakes. It only had to be 12 volt to operate the lights or brakes. I use it to test to trouble shoot if there is a problem or after doing a repair on any of these circuits. To charge it, I added a 12 volt power socket on the outside that I can connect to the 12 volt socket on my vehicle while I am driving. The socket on the ammo can can also be used to operate anything that can be plugged into the 12 accessory socket. It has the digital display that shows the voltage and also shows the current amp usage of whatever it is operating. The amp readout is great for testing the trailer brakes. By looking at the amp readout, you can tell if one of the brake electromagnets is bad or not.
That sounds like a perfect application. Thanks for sharing.
David wearing safety glasses. Norm Abram approves.
awesome!
Thanks Jehu. I really appreciate that coming from you.
Sure! It’s easy to teach something if the audience already knows all your ackronyms! That’s like teaching into the mirror. Only needs one person, no empathy and no thinking. Bye.
@@jayclark8271 this comment is a POS
Thanks for the video, been looking into building a DIY eBike and building my own battery pack for that so I have been watching just about everything I can using 18650 cells haha.
That's exactly what I use except with a IEC/UPS kettle connection,I can't guarantee that mine are water proof but it's an innie connection so water will have trouble getting in
Thanks David, please do another video of this kind,respect from Kenya!
Edit,am addicted to 1860 battery build but nowhere to be found in this part of the world
That spot welder is the business, isn't it?!
As always, great work David.
It's pretty good. Let me know if you think I should make a video on it.
@@DavidPozEnergy No, I think you should give it to me to make a video on 😉
Seriously though, leave that to the manufacturer. I was building one of my own, but that one looks so good I think I'll buy one. Who did you say made it?
LOL. I don't know who makes it. But Keith sells it through his company 18650ed. 18650shrinkandcellholders.com/kweld/
@@DavidPozEnergy Yes, make a video on how to best built it from the parts. intersting gizmo indeed.
In my experience the red ones are always the ones that give me problems so I agree with your strategy of not using them if possible.
There's cheaper options for brand new all one brand cells instead of salvaging just gotta know where to look
You did not current test the battery. Thus you couldl have a unbalanced bank of batteries after a few use (think of one bad battery). This could lead to one of your banks becoming drained and reversed charged. That could lead to one large fire. does the bsm have a low voltage bank alarm or are the tabs also a fuse? What was this design based on?
I have a previous video testing cells.
I've been thinking about doing this with my ammo cans!! Thank you!!!
such a nice build
Dave, loved the video. I live in Woonsocket and not far from 18650 Heat Shrink & Cell in Lincoln. Sounds like you are not too far away either. Would love to grab a coffee sometime. I have a slide in truck camper that I want to put 200-300 watt panels on and a couple of Lifepo4 batteries so I can boondock for a week or two off grid without starting the generator.
Sounds like a great project. Can you contact me through Facebook? facebook.com/DavidPozEnergy/
I've also some bad luck with the red Sanyo sells, they are really hot when i use them and i had some old ones in the past that had leaked, no other brand that i've personally seen had done that
Does it not matter that they are different max amp rated batteries?
i love finding those LG's in laptop batteries. they are so dependable.
Very good video. And interesting of course useful.
I would like to see how you charge this battery
Retired Snowbird solar ✌️
love the spot welding
The technical jargon is WAY beyond my brain capacity, but still a very cool build vid!
Great job, very knowledgeable
That's a great little project! People will be able to follow along.
Hey, on your miter saw, have you considered powering it with DC? It's probably got a "universal" motor that will run on either DC or AC. You'd need a 120 V pack, but you wouldn't need an inverter.
Keep the projects coming!
Do you know of any blogs or videos where someone has done it. I don't want to experiment with such an expensive tool.
You’d need a beefy external power switch. D.C. arcing can destroy an AC power switch in short order. (See what I did there?)
Brilliantly designed pack! I've would add third wire to buss bars. Do not leave these voltage monitors / ballancers unattended in the pack. From what I remembered they drow their supply only from one cell in the pack. If the pack is left for long time without charging, this cell will be drained. Keep the good work
Thank you. Yes, that's correct about the cell checkers.
Great video, great build. Thank you for sharing and disclosing the sources.
Great video
Great build. I have 2 packs almost identical to yours. I use them to power my tandem trike. I used Samsung CGR18650DA cells and can pull 40A without any problems. I wish my packs looked as good as yours. Thanks for a good video.
Is there like a safety fuse for overload or short - is there like a safety fuse for the batteries ?
Yes. I used a circuit breaker inside the box.
what is advantage of all this work to spot weld 168 cells together vs buying the big flat battery packs which are high amps/capacity and only having to solder in a dozen spots?
For padding, I would suggest either a 5mm craft foam or the anti-fatigue mat available from Home Depot. It will not likely break down, unlike bubble wrap, and can be better cut to shape.
Thanks. I'll check it out.
Have you considered the Headway 38120 LiFePo4 batteries from batteryhookup for your Mitersaw? Maybe only in 24v for less weight. They are huge and their discharge rate is very high.
Sure. Nothing wrong with those, the specs are great.
What happens if a battery goes bad and shorts? No individual battery fuses? Looks like maybe those little rings that are spot welded have a smaller tab connecting to the rest that could burn off perhaps?
The nickel Strips He uses from battery hook up has individual fuses for each cell
Nice I was waiting for you to start with 18650 cells. And yes I want to see a high amp 18650 cell pack or 21700 cells. Keep up the good work David. Greetings from Spain :)
did you ever test it
Hey Dave if you see this. You have to go to harbor freight and get a pair of icon flush cut s. There expensive at $40 but lifetime warranty. I use them to cut the nickel off the cells. I did over 500 cells with my set. And they still cut like new.
Thanks for the tip
Great job bud !
Very professional.
Hi Dave, just watched this video of yours and liked it a lot. I was a little concerned when I saw you wrap that tape and then the shrink wrap around the whole bundle. I know it looked nice and neat but I was concerned about ventilation and air cooling. At the end you mentioned removing the gasket, and I assume that was what that was for, but with all the tape and wrap, there is no way you can get any air cooling. Just my thoughts. Thanks for the videos. M.
Heat dissipation is a concern for heavy loads or fast charges.
Author mentions limiting the max amps for that reason.
20A max / 12P ~ 1.6A per 14S group, should not generate too much heat from 2.2Ah rated cells.
For protection a BMS with thermal shutoff function could be used with sensors distributed within the block.
Wow You are a good teacher
I tried the link for the spot welder you gave but I didn't get a connection. Any chance you could give another link for that welder. Thank you
Please do a video with those high discharge Ryobi cells! I have a bunch and wondering how capable they are
skucome they used to say in the old days good job dude
Hi David, once again awesome video! A few things, you need to sort the cells into banks capacity wise , the reason being when drawing current from the pack if one P has a lower capacity it will drain faster than the others, thereby causing the pack to discharge faster than it otherwise would have. There is an online cell logger I think on battery hookups site? Not completely sure on that one so don't quote me there, Average Joe uses it when building his batteries to closely balance his P's capacity wise. The other thing I would have done before heat-shrinking the battery would have been to charge it up and do a full few cycles drawing enough current so that you could monitor the cells with a thermometer or if you have one an IR thermometer so that you could see if there were any problematic cells before sealing everything up. It would suck big time to have to tear it all down just because of three or four cells not wanting to play nicely together. There are a few downsides to using recycled cells, BUT, it sure beats the crap out of a LA battery, AND! You DIYed IT! Once again, Awesome build.
I agree. The website is repackr. You put in all the cell capacities and it organizes them for you. I wanted to do this, but couldn't. The tester I used was way out of whack. I couldn't trust any of the numbers it was giving me. If I had used some Opus testers, then I could have trusted the numbers and I would have used repackr. that was my original intent. The only good thing about the tester I used was that it charged and discharged the cells heavily so I was able to see if there were any "heaters". (none). I plan to do a follow up video with some testing. I'll let you in on it. I discharged the whole thing in under 2 hours, (high amps) and we did not exceed the cells data sheet for maximum temperature.
I would drill some holes in the ammo can if you're going to keep the lid on. If the cells experience thermal runaway the extreme pressure inside a sealed metal container could be dangerous.
The gasket is removed on purpose to allow venting and no pressure build-up.
Decent, except for the low amperage. Much of the fun of using that size battery is being able to draw hundreds of amps out of them when needed. I use only 6 of the 18650s in a portable "juicer" for my smartphone and it works well. I just used a "hodge podge" of batteries, some new, some used, I didn't care. It can charge my smartphone 3 times from 0 to 100% before it needs to be charged too.
This would be a nice way too power up your RV camper. Small, and can be daisy chained in series for more amp hours. Imagine 6bof these in a camper, with solar panels on the roof, and a nice inverter. I imagine one could get several days off a bank of 6 of these.
David there is a plastic sheet called Coroplast that is like plastic cardboard. It is commonly used to make signs and you can get it for free from some gas stations when they throw their signs away. I prefer to purchase 4X8 sheets and cut it up to make my dividers and covers. I use Kaptom tape where appropriate but only use packing tape on the Coroplast because the Coroplast in not high temp so why use high temp tape. Your plastic bottle is also not high temp but the Coroplast is much easier to use. Coroplast comes in different thicknesses the 4mil is the easiest to find and is what most gas station signs are made of. I much prefer the 2mil type but you will need to go to sign store to buy it!
If you are a good engineer I wish I was born in America and would have come to you and taken a lot of knowledge.
Thanks for sharing David. I was wondering if you would mind giving me the best lay out and component values that I would need in order to build a 220 to 240 volt 5 kilowatt off grid solar system? Themis.
For the first time I get how fuse strip works out... If a battery shorts, the fuse melts and disconnects battery.... Why did I have such a hard time sorting that out...
that would make a savage battery for my 48v 750w ebike and id love to do a build like that,but id be nervous as hell that id mess it up
that leftover nickle scrap would be great for electroplating
With 12 batteries in series, with 1 amp fuses. Do you not have ~12-15A discharge before your fuses blow? ... Even before the midnight solar breaker trips?
I have 12 cells in parallel. The nickel fuse strip is good for 3 amps continuous. And the cells are rated for 3 amp continuous discharge. So the build can handle 3a times 12 cells = 36 amps. The circuit breaker is 20 amps so it will pop before the cell level fuses burn out.
@@DavidPozEnergy so, what you are saying, with the nickle strips, in this case, you do not need the glass fuses which hbpowerwall adds to all the packs?
Hello, do u have a project that would produce a pack that could be carried in a back pack to power corded tools like a lawn mover, a weed eater or a leaf blower
Yes. Here is the video on the battery I recommend for that: ua-cam.com/video/8nn7EWmLs1k/v-deo.html And here is the video on the back pack build: ua-cam.com/video/7kYrtXuIY-E/v-deo.html
Very Nice
do you have a video on that spot welder?
Not yet, but I am working on one. It's a K-weld bought from here: 18650shrinkandcellholders.com/
Thanks for sharing. Would it be too much trouble for you to give me the best lay out system and values of the components I would need to build a 240 volt 5 kilowatt off grid solar system. Thanks
Great video. How would you make a car battery replacement?
I can’t find that spot welder via the links you posted, can you please help me out locating one?
Cool project.....what do you think your total cost was minus labor...... how many charge recycles do you think you'll get? Thanks
I was just under $200 in parts (cells, nickel, BMS, etc.)
Nice build! Best practice would be to crimp and solder the connection from your bussbar to the BMS.
I don't know which is best, crimp only, or crimp and solder. But I do know that no matter which way I do it, there will be people telling me to do it the other way. LOL. When I made my video on LTO I crimped and soldered and received quite a bit of negative feedback for that.
DavidPoz Haha, I made a video with crimp and solder and received similar feedback. One of my electrical engineering profs justified the crimp and solder method stating that the solder wetting the copper prevents copper oxide from forming at the junction. Copper oxide is significantly less conducive than copper metal. Additionally the solder helps prevent the connection from wiggling loose as the crushed copper deforms over time from the pressure causing the connection to loosen up. Just my 0.02- I’ve never had trouble with crimp and solder and have seen crimp only fail many times before (mostly due to bad crimp jobs though).
Thanks for your 0.02. I like your explanation, make a lot of sense.
I got a hundred of those packs last month. Still working on the damn things.
Me too. I bought more during that big sale and am working on them.
have you looked at incorporating super caps into builds? could they be slowish charged with batteries for short bursts of high power, such as starting the miter saw?
I don't know enough about sizing capacitors to pick the right ones for a build.
@@DavidPozEnergy neither do i, i just watched an interesting video: search: fully charged supercapacitor
I didn't hear you mention that the tape is kapton (and why), not just a cheap yellow packing tape. My first question was, what do you need a 48v battery pack for? (wait til the end) You did vaguely mention "add to your system" and "my tower of power".
Yes, that was Kapton tape. My stuff is all 48v.
How much would you charge to make one for someone.
It would be cool to make a can for conversion. Mainly a 48 to 12 DC to DC converter. I am thinking about making something similar for Ham Radio. How is the heat? I was thinking about liquid cooking it. For the surge of the saw, a large cap could help out.
If your radio is 12v, then you can modify the design to make a 12v battery. Then no converter is needed. But, there are lots of 12v lifepo4 batteries on the market, so you have choices if you want to buy one.
harbor frt sell plastic auto body tools which I use when I am dismantling lip packs. I believe it is a safer way to get salvaged batteries.
Very very nice. Thanks.
So at the end you gave us an application where this setup does NOT work (your mitre saw) .. but what would some applications be where this WOULD be useful?
I could hook this up with my small inverter and power my home refrigerator/freezer for about 30 hours.
Thanks David.Where is the link for the spot welder?
The spot welder is called the "Kweld". It is sold by Keith, owner/operator of "18650ed" in Rhode Island. You can call/e-mail, or message him in facebook to place an order. I'm not affiliated with his company. I bought mine from him at full price and it works great. I wish Keith had a way to just buy it online, but for now at least, you have to e-mail him. 18650shrinkandcellholders.com/kweld/ I bought the cell holders from him too.
@@DavidPozEnergy Thanks again David for your rapid reply
you could use them for a Golf Cart 48v times 4 of them would give you over 5 kwh . You would need to put at least a 400 watt controller I think. If you went easy you could probably go 3 rounds of golf before a re-charge.
Would 2 be enough to just drive around the neighborhood? I'm restoring an old EZGO Limo and want to drop weight and charging from the lead batteries
Specializing in manufacturing 48v36v golf car lithium iron phosphate battery pack
If There was ever a major failure and the fuses had to blow. I'm not sure that plastic bottle would insulate against short circuits. I just watched the video that average Joe done with his thermal cam. Showing the fuses blowing. I would love to see that test. Love your vids mate
Do you have any suggestions of something thin, non-conductive, with a higher temperature rating? I think 2-liter bottles are PET plastic, which is like 500°F. I think that's higher than the plastic in heat shrink, but I'm no engineer. There is also 2 layers of tape in the sandwich. I saw Average Joes video. It was great.
Is there a possibility for such a box with 12V output that can handle 3000W 12V - 230V without problems even for a loooong time??
Yes, but it would be much larger. I built a 12v version, but you would still need 3 of them to handle a 3000w load. ua-cam.com/video/6Ai5IRQbLcc/v-deo.html
It seems like you have a great workshop and lots of tools. Were you building a different kind of projects before you got into the power walls and solar?
I was a contractor, and energy auditor.
Great build. Looks as good as factory made. Only concern I might have is with the ammo can is if there is any interior heat build up. How would you know before a cell goes thermal runaway? The can being fully enclosed would also not allow much ventilation of the packs. Maybe do a strong load test and show monitored temps at various cells IN the closed can and the outside metal of the can. Maybe the can is an adequate heat sink to air, but does not help if a cell becomes a heater. Great job!
It's always about compromise. You can have wide open cells in the room, but no fire protection. This takes the approach of enclosing the cells to protect the room. The downside is you have to limit the amps to limit the heat buildup. That's why I used a 20 amp circuit breaker. The cells could do twice that. I have been doing a series of tests on it at different amps and measuring the heat buildup. It will be in a future video.
Hello, can I load this selfmade battery with an manual 20 Watt handgenerator?
you'll be there a while