Most exellent of you for not editing out the mistake in wiring the second set of sensors. It is so helpful for us to see how you approached and managed this uncomfortable situation in a thoughtful and precise manner. I applaud your humility.
This might be the best video I have seen on DIY LiPO4 battery construction. Certainly the best explanation of the reason for balancing, differences between top and bottom balancing, etc. Very well done video!
I agree. So many DIY videos that lack complete explanations. Also, seeing his mistakes is a good indicator of where things could go wrong, and, what to watch out for. Excellent Video. Thank you.
16:40 All the cells WILL indicate the same voltage as they are connected in Parallel. Only way to measure individual voltages is to disconnect either positive or negative terminals. The end result stays the same as you were trying to get the cell voltages closer to each other which you achieved by charging in parallel. The rest is very informative for the newcomer to LiFePo4 batteries. Good video sir.
An excellent step by step breakdown for mere mortals who are interested in building their own packs, you have done exceptionally well with your presentation, taking the time to explain what is important along the way and WHY it is important as well. Thank you very much you have another subscriber.
You probably didn't plan it, but making a mistake with one of the BMS wires at first was a nice demonstration of what and why you're testing the connections :)
This also shows that any one even an electronics guru can overlook a detail that could cost and shut down a project. Great demo of double checking your work. The signs of a good teacher that is unafraid of admitting he is human. Thank You. I now feel obligated to subscribe.
Just came across your video showing how you build a LFP battery. EXCELLENT! Wish I'd had it before I built mine, although they are working wonderfully. thanks again.
I'm in the process of converting my scooter to electric using the existing CVT (modified to reduce power losses). The mechanical part is a piece of cake for me but building the battery turned out to be a major headache. Thank you for explaining it in an easy to understand manner.
I might be missing something. @16:22 you are measuring the individual cell voltages but they are all parallel connected. Isn’t that the reason all the voltages are pretty much the same? Wouldn’t that be better if you remove the wire and measure them individually? Thanks!
Got to give the credit were it is due... and sure its due to you, best teach skills I've seen by MILES (and I've watched not hours but weeks on tuts) best aproach...viewers know nutn 🙂and you did nicely xplained point after point no MORE or LESS info and a clear and good view on the task at hand, I know when reading these three lines it dnt look like a big deal but its a fact that the most cant cant get that tutorial vid just right... soooo, not the teacher but THE MASTER 🙂 🙂
This was a great video, before I was confused about building a battery and now I'm ready to try it myself and I'll probably watch this a few more times.
Good video. helps with troubleshooting too. Importance of balancing was well discussed, as was BMS and care in installation. Good to make an error and demonstrate recovery. I would add 1) mention how you were careful with box cutter, 2) verify that the brass/silver = -/+ was true polarity in ALL cells, 3) I work in an area where a fire could be easily controlled, or at least reacted to. 4) drop your deep socket and watch out! short city 5) wiring for charger on the inside of terminals? asking for trouble.loose wire ,ditto. 6) "I don't see smoke. Good" Strong work
At 16:36 you are testing cells connected in parallel so you are not checking the voltage of an individual cell, rather you are checking the voltage across all the cells. The reading will be the exact same along the wires (baring a large current moving through a small wire causing a voltage drop). Also you initially set the power supply to 3.6V in the hopes of charging them to 3.65V which can't happen. I see later on that you increased the power supply voltage to 3.7V.
also the testing of the 4 feet wire on the end. he does not know what copper resistance is, or at l;east does not know the voltmeter is of high resistance, so in test it does not matter. with ballancer you will have current and so will have copper resistance that is relatively more important.
@@LoekiNL These were my two criticisms as well. Though in the case of the BMS sensor wires I'm guessing that the BMS current draw is not high enough to produce any significant voltage drop.
Thank you for this video. It is (by far) one of the most helpful and informative videos on batteries I have seen! I'll be coming back to this a lot as I build my own.
When you top balance, use #10 or larger leads from the power supply, put terminals on both ends and don’t use it the banana plugs or alligator clips. Connect the leads to the two common rail taps but at opposite ends so no path is shorter or longer than another. Not at the center as shown during balancing.
I realize tha this video is 3 years old, but I just discovered the "magical" difference that Lithium Iron Polyomer has compared to Lith-Ion I have been using. I know that there is a chemistry that requires the pack have a constant positive pressure. Is that LiPo that I am thinking of? And if this video is 3 years old, what are you up to these days? My subscription is earned. #trustory
Your remark about shortening the BMS wires is true if they are only used for measurement but not neccesarily true if they are used for cell balancing. When you measured with your meter you are only loading the battery with a 10M Ohm load so drawing 50 microamps. If the BMS is active balancing it can only read the voltage at its end of the wires and you will get some voltage drop across these wires which will be different if they are different lengths.
VERY GOOD VIDEO - everything is carefully planned for easy explaining! A near perfect explainer video. I suspect your channel is very underrated - as an electrical engineer myself, I have a feeling that it won't take long for your channel to grow exponentially! Subbed & Liked!
thanks for this video. thanks for this. the mistake is a humble process that you did not remove. It will also help me to be careful. thanks much and God bless you.
Very professionally explained! Thanks you. One question: what resistor do you use to avoid the spark at the convertor and where do you connect it to discharge the spark?
for 12v use 12+Ohms 24v - 24+Ohms 48v - 48+Ohms this type of resistance will allow only 1 amp to flow. You just need to do it once when connecting wires to inverter terminals.
Красиво получилось. Одно замечание. Между банками классно бы поставить листы диэлектрика. Сами банки у вас подключены между собой шинами. В случае если перетрется, оплавиться, расплавиться, да что угодно случиться с изоляцией самой банки у вас будет К.З. И в отличие от ленты из никеля контакт хороший. Можно еще подумать о плавких предохранителях. Но, это уже на любителя. П.С. Спасибо за видео.
Brother excellent detailed video you have answered all the questions in my head on how to start off lifepo4.. Many Many Thanks for your videos! Happy New Year. Gokhan from London
Hi from Australia Very Very much enjoyed you video , Great information and easy to listen to. And professionally presented ............. Extremely helpful A big thank you ( Liked and Subscribed )
merhaba . 60 & 72 v bir sistem kurasaydınız izlenme oranlarınız çok daha fazla olurdu.Bu videoda çok başarılı olmuş. çok fazla emek harcadınız.teşekkürler.
At 16.24 you check the individual cell voltage of 16 cells connected in parallel (joined by 4 strand copper wire ). How do you measure individual cell voltage if cells are still connected in parallel? It also appeared that the power supply was still connected. If the cells are still in parallel and you measured a different voltage on one cell then you have a big problem.
This is a wonderful explanation. It is most interesting the mistake you made in connecting the balancing cables. This has been my worry though I wire correctly but I imagine what would happen if such error occurs. Thanks greatly for sharing the video.
Do you have an idea how battery's manufacturers top balance the battery cells since it takes a long time and they produce a large number of cells, is there a special machine for that or another fast method to do that ? Thank you.
Спасибо за тест. Не согласен только с последним доводом - провода от BMS до ячейки обрезать по длине не рекомендуется. При использовании ячеек необходимо снять все наклейки с предохранительных клапанов что между клемами. Час назад сделал заказ на 16 штук (по вашей ссылке). Собственно от туда я сюда и пришел)) Еще раз спасибо за видео и всего наилучшего!
here is a quick tip, connect all batteries in parallel initialy for a couple of hours before connecting them in series, they will all equalise to the same voltage
I was gonna say... isn't he missing a step here, which is just leaving the whole pack set up in parallel, with the copper wires, for a while to let all the cells balance out on their own? I'm still learning this stuff myself but seems this is what other DIYers do.
I would like to say thank you very much I thought your video was very good I found that you explained everything very well from start to finish Cheers Anthony
Fantastic Video! Very informative and educating! Only small suggestion I have: It helps the batteries to last longer if you compress, but I think you know that already.
enjoying the video, one comment, checking the individual cells when they are still connected in parallel will give the same voltage for every cell. It doesn't matter which one you check, you are really just checking all, every time ....
Am assuming if you connect 4 cells in parallel to give aprox 12v, you'd only need a bms for 4 cells as the voltage would be the same as they are connected together
Very informative. I would say however care needs to be taken with these Aluminium case batteries. With some of them the case is connected to the -VE terminal of the cell. When the cells are stacked together if somehow the plastic wrap on the cells rubbs through it can cause a short and possibly a fire.
@@fraserlynn9488 Some of the cells I have seen have plastic caps that sit on top and bottom and this makes a gap (about 5mm) between the cells. This could be re-created using some type of insulator between cells.
If I want to charge this battery then does that happen through that x60 connector that goes directly to BMS? And If I want to power up some device then should I use the big end terminals on battery pack?
I think that the the zip ties do not provide enough tension for compressing LiFePO4 cells (specs for much larger cells recommend >300 kgf). Anyway, some compression is better than no compression. Front & back plates would distribute the compression force far more evenly.
This video is so informative, more so at the mistake where one wire was wrongly attachwed, however i have a question, i have a 60V 19S BATTERY but the 13s cell group reads 0.0v , so the total voltage of the battery is less by around 3.n Volts which is failing the battery from charging but when i use a wire to skip/jump the 13s cell group and link the 12s to 14s groups the battery charges though the wire heats up. does that mean the 13s cells are dead? their connections are intact. can i disconnect the 13s and link the remaining 14s to 19s to the other series with the same BMS?
Thank you for The good explaining and moore, it's easy to think that you maybe are a University teacher or something... Greatings from SWEDEN for a very PRO Channel! 😀
About those BMS leads, and no need to be same lenght. Is it because of the low current, because only measuring voltage with low balancing current? What is maximum balancing current at your BMS, or do you use separate balancer? Can you make same test/simulation with different leght of wires and current like 2-5A for balancing?
I have ×3 100ah batteries with built in bms on each. I tied them in parallel to make 12v 300ah. What is the battery series so i can input that correctly on my smart mppt controller
I tried charging a 12v 280Ah Lifepo battery (internal BMS not bluetooth) at 14.2 v & 4.5A and smoked my cheap Alibaba (30v/5a) PSU in 30 seconds... what went wrong?
that cutoff would I guess be because of the cutoff settings i think your BMS came preconfigured for LiPo instead of LiFe and there is a huge cell voltage difference. LiFe is 2.5v - 3.7 where LiPo is 3v - 4.2v
@SolarEngineering thanks for the awesome video. Question: I am thinking of building one for myself. But I am going to slowly increase the amount of batteries. I will start with 8 batteries and then add another 8 batteries. So if I buy a 16s BMS ,can I leave 8 connector cables from BMS unattached? - as first time I will have only 8 batteries.
Some BMS supports 8s-16s config (meaning that you could use it with 8 to 16 cells), other BMSs fixed with an exact number of cells. Check BMS specs or ask the seller.
@SolarEngineering if I make 12v out of your batteries then it will be 4p4s and 25x4=100Ah. Do I connect the BMS same was as this video? Also how to charge them after I configure them in 4p4s for 12v 100Ah? A video on this configuration would be great.
Hi, yes 16 batteries for 12v batteries will be 4p4s configuration. You'll need to use 4s bms and connect sensing leads same way as in video. You'll have only 5 leads (1 negative and then each group of paralleled cells positive). you could see example of 2p4s here: ua-cam.com/video/Cw-5KcKCKzM/v-deo.html
FANTASTIC!!! Being a newbie this has really helped fill in a lot of gaps. I guess you used a 250watt light bulb for the 5 amp drain? For recharging the pack, you used your DC power supply though the BMS at 5 amps.. is this correct? Thanks again for taking the time to do this. Also the graph gave a perfect explanation for the need to balance! Well done!
The parts with shipping for my 24V 200ah Battery is about 800.- plus bms and small parts all in all less then 1000.- € against some commercial resellers who wants to get 4500.- for the same setup. I also bought 2x 290 Wp Solar cell for 90.- plus a mppt 200/20 with price tracker from amazon for 130.- So all in all i can now build up a great solar system with 580Wp and 200ah Batterie for less then 1400.- against commercial seller who made me offer with minimum prize 6500 .- up to 8000.- and many weeks waiting time. Sometimes its really worth watching videos and diy it yourself. And if anything fails while i am on the road i can fix it myself and have a deeper understanding whats going on.
BMS that I'm using in this video pretty good, here 8S version for 24V www.aliexpress.com/item/4000828229543.html?spm=a2g0o.store_pc_home.productList_8327557.subject_10
Very good thank you. Just one comment on the last part of wire lengths you may be right but the way you tried to demonstrate it is not accurate IMO due to the high voltmeter impedance it will not draw any voltage drop however that may not be the case of the BMS.
Regarding the length of the balancing wires, of course when you compare the voltage at the battery terminals and when using wires (AWG24 in your example) between the battery and the Voltmeter, you won't see a difference because the Voltmeter draws almost no load. But if the BMS adjusts the voltages between battery cells with e.g. 5 Ampere, then different lengths of the balancing cables might make a difference. Because due to Ohm's law, the voltage / power loss in the cable is I*R / I*I*R, that is, the power loss increases quadratically with the current. So that the BMS senses the cell voltages under the same conditions, I would recommend not to use different cable lengths.
I know only one active balancer that could do 5 Amps, this balancer going with really thick wires. Most of the BMSs have passive balancers and only draw mA to balance cells. But you are right it's worth mentioning that equal length balancing wires could be required for some applications. Thanks.
You are correct most BMS only draw 65 MA but that will cause a voltage drop of a few MV but the BMS is measuring MV and can cause the BMS to not balance correctly if the leads are not the same length.
6 місяців тому
Grear video! Thank you for your work! How much power can this batery pack deliver continously? How many Amps?
What kind of load are you putting on a battery bank such as the one in the video? I’m looking at starting to build 1 battery bank at a time to help power my shop. Do these style batteries have a good life span on them as far as daily use and overall life? Thank you
I'm just using 48V inverter (here is example: amzn.to/3seiyiV) I haven't tested this exact batteries for long time, but in general LiFePo4 can 2000+ cycles before it's going to drop to 80% of original capacity.
Hello, thank you very much for the super instructions that I am recreating. The parts are all ordered. My question: Can two such, completely identical systems of 16 x 3.2 V 25Ah LiFePO4 batteries each with a BMS 16S Lifepo4 50A be connected in parallel, so that 1 large battery with 48 volts and 2,560 Wh (= 2 x 1,280 Wh) arises? Vielen Dank und viele „greetings from Germany”!
After getting them to 12 volt would you than still be able to connect the second battery bank in parallel to the first battery bank? If they both match in Voltage and amps?
I have some Honda Insight cells in there original 18 cell cases, I would like to make 4S4P 16 cell 14.8V packs to use in my RV. I'm pretty new to battery building and was wondering if you might have an opinion on what BMS to purchase for this application? I will be building 4 packs and wiring the in parallel. Thx for any advice. Love your videos, they make the most sense of any on the internet to me.
I like this BMS: ua-cam.com/video/k8Wkg-tVnx8/v-deo.html Also recently got Daly BMS (last video on the channel), but haven't tested it yet. It looks promising, going to perform tests soon.
Most exellent of you for not editing out the mistake in wiring the second set of sensors. It is so helpful for us to see how you approached and managed this uncomfortable situation in a thoughtful and precise manner. I applaud your humility.
thank you for the feedback, appreciate it.
This might be the best video I have seen on DIY LiPO4 battery construction. Certainly the best explanation of the reason for balancing, differences between top and bottom balancing, etc. Very well done video!
I agree. So many DIY videos that lack complete explanations. Also, seeing his mistakes is a good indicator of where things could go wrong, and, what to watch out for. Excellent Video. Thank you.
16:40 All the cells WILL indicate the same voltage as they are connected in Parallel. Only way to measure individual voltages is to disconnect either positive or negative terminals. The end result stays the same as you were trying to get the cell voltages closer to each other which you achieved by charging in parallel. The rest is very informative for the newcomer to LiFePo4 batteries. Good video sir.
yeah I missed that step, thanks for letting me know. And thank you for kind feedback.
))) that is what attention to detail is ! Although the mistake was obvious once you know .... but I did not see it until I read your comment !
Yep lol
Best DIY LifeP04 so far, in a similar video to this, i have to go through about 5 videos just to see to the end.
The best splaning ever made. Congratulation! Very Good Work man!
An excellent step by step breakdown for mere mortals who are interested in building their own packs, you have done exceptionally well with your presentation, taking the time to explain what is important along the way and WHY it is important as well. Thank you very much you have another subscriber.
Much appreciated!
Your description is very good. You explain step by step what must be checked before entering the next stage.
Glad it was helpful!
This was the best explanation of how to build. You explained each step vs just rushing through.
thanks!
You probably didn't plan it, but making a mistake with one of the BMS wires at first was a nice demonstration of what and why you're testing the connections :)
totally unplanned, glad that I didn't burn BMS
@@SolarEngineering You showed why it's important. Bravo!
This also shows that any one even an electronics guru can overlook a detail that could cost and shut down a project. Great demo of double checking your work. The signs of a good teacher that is unafraid of admitting he is human. Thank You. I now feel obligated to subscribe.
Just came across your video showing how you build a LFP battery. EXCELLENT! Wish I'd had it before I built mine, although they are working wonderfully. thanks again.
glad it was helpful!
I'm in the process of converting my scooter to electric using the existing CVT (modified to reduce power losses). The mechanical part is a piece of cake for me but building the battery turned out to be a major headache. Thank you for explaining it in an easy to understand manner.
nice, glad that video helped!
I'm on exact that same path with the same findings
"OK. I don't see smoke." LOL
This was an *excellent* video. I learned a lot. Thanks so much.
Glad to read that! Thanks.
I might be missing something. @16:22 you are measuring the individual cell voltages but they are all parallel connected. Isn’t that the reason all the voltages are pretty much the same? Wouldn’t that be better if you remove the wire and measure them individually? Thanks!
that's correct, missed this step, busbars should be disconnected.
Got to give the credit were it is due... and sure its due to you, best teach skills I've seen by MILES (and I've watched not hours but weeks on tuts) best aproach...viewers know nutn 🙂and you did nicely xplained point after point no MORE or LESS info and a clear and good view on the task at hand, I know when reading these three lines it dnt look like a big deal but its a fact that the most cant cant get that tutorial vid just right... soooo, not the teacher but THE MASTER 🙂 🙂
This was a great video, before I was confused about building a battery and now I'm ready to try it myself and I'll probably watch this a few more times.
glad it was helpful.
Good video. helps with troubleshooting too.
Importance of balancing was well discussed, as was BMS and care in installation. Good to make an error and demonstrate recovery.
I would add 1) mention how you were careful with box cutter, 2) verify that the brass/silver = -/+ was true polarity in ALL cells, 3) I work in an area where a fire could be easily controlled, or at least reacted to. 4) drop your deep socket and watch out! short city 5) wiring for charger on the inside of terminals? asking for trouble.loose wire ,ditto. 6) "I don't see smoke. Good" Strong work
really good points, thanks
At 16:36 you are testing cells connected in parallel so you are not checking the voltage of an individual cell, rather you are checking the voltage across all the cells. The reading will be the exact same along the wires (baring a large current moving through a small wire causing a voltage drop). Also you initially set the power supply to 3.6V in the hopes of charging them to 3.65V which can't happen. I see later on that you increased the power supply voltage to 3.7V.
This is what I noticed also immediately. Just checked the comment to see if i was the only one. Does this guy know what he is doing?
also the testing of the 4 feet wire on the end. he does not know what copper resistance is, or at l;east does not know the voltmeter is of high resistance, so in test it does not matter. with ballancer you will have current and so will have copper resistance that is relatively more important.
@@LoekiNL These were my two criticisms as well. Though in the case of the BMS sensor wires I'm guessing that the BMS current draw is not high enough to produce any significant voltage drop.
What resistor to precharge is used? Top explained, to the point! Thank you!!
For 48V 30-60 ohm will work
thank you for kind feedback
Thank you for this video. It is (by far) one of the most helpful and informative videos on batteries I have seen! I'll be coming back to this a lot as I build my own.
appreciate your feedback
Wow I'm learning more from this!
May you live longer SIr!
thank you for the feedback!
Always learn more when I watch your videos! Thanks, J
thanks!
When you top balance, use #10 or larger leads from the power supply, put terminals on both ends and don’t use it the banana plugs or alligator clips. Connect the leads to the two common rail taps but at opposite ends so no path is shorter or longer than another. Not at the center as shown during balancing.
good to know, thanks for the advice.
I realize tha this video is 3 years old, but I just discovered the "magical" difference that Lithium Iron Polyomer has compared to Lith-Ion I have been using. I know that there is a chemistry that requires the pack have a constant positive pressure. Is that LiPo that I am thinking of? And if this video is 3 years old, what are you up to these days? My subscription is earned. #trustory
Your remark about shortening the BMS wires is true if they are only used for measurement but not neccesarily true if they are used for cell balancing. When you measured with your meter you are only loading the battery with a 10M Ohm load so drawing 50 microamps. If the BMS is active balancing it can only read the voltage at its end of the wires and you will get some voltage drop across these wires which will be different if they are different lengths.
I am about to tackle a similar project with 48(!) prismatic cells. This video is perfect timing 🙂
48 in series??
@@SolarEngineering Not quite. Ultimately a 16S3P, but they have to be top balanced.
@@PawlSpring ah I see, I have same bank 3p16S. ua-cam.com/video/RB_O_5Ppv7g/v-deo.html
VERY GOOD VIDEO - everything is carefully planned for easy explaining! A near perfect explainer video.
I suspect your channel is very underrated - as an electrical engineer myself, I have a feeling that it won't take long for your channel to grow exponentially!
Subbed & Liked!
haha, I wish your words become a reality :)
Thanks for the feedback.
thanks for this video. thanks for this. the mistake is a humble process that you did not remove. It will also help me to be careful. thanks much and God bless you.
glad it was helpful!
Hey bro how long take them to ship to you?.
Thanks for taking time to share your knowledge.
Looking forward to working this out. Randy. helperdude2016@gmail.com
Thank you for your video. Great information that is easily understood. Well done! Looking forward to your other videos.
Very impressive & informative I liked the info in the drop down too. Links/time codes etc.
Got my mind working overtime now.⚡️
thank you for the feedback!
Very professionally explained! Thanks you. One question: what resistor do you use to avoid the spark at the convertor and where do you connect it to discharge the spark?
for 12v use 12+Ohms
24v - 24+Ohms
48v - 48+Ohms
this type of resistance will allow only 1 amp to flow. You just need to do it once when connecting wires to inverter terminals.
How can I get this product
Красиво получилось. Одно замечание. Между банками классно бы поставить листы диэлектрика. Сами банки у вас подключены между собой шинами. В случае если перетрется, оплавиться, расплавиться, да что угодно случиться с изоляцией самой банки у вас будет К.З. И в отличие от ленты из никеля контакт хороший. Можно еще подумать о плавких предохранителях. Но, это уже на любителя. П.С. Спасибо за видео.
спасибо за совет и за отзыв.
Top shelf instructions. Thank you for your clear, and concise directions..
your feedback is much appreciated.
The best explanation in youtube on DIY battery pack ! 👍
appreciate your feedback
30:00: "I don't see smoke ...". Sounds so familiar to me :)
Thank you! Appreciate you really explaining each and every step so thouroughly.
Brother excellent detailed video you have answered all the questions in my head on how to start off lifepo4.. Many Many Thanks for your videos! Happy New Year. Gokhan from London
appreciate your feedback
brilliant step by step video tutorial. well done
Hi from Australia Very Very much enjoyed you video , Great information and easy to listen to. And professionally presented ............. Extremely helpful A big thank you
( Liked and Subscribed )
Thank you very much for your videos. I happen to have to do mine with 8 batteries and this video will be very helpful. Thanks again.
glad it was helpful!
Very nice build. Very organized. I like it. Big thanks for the information
thanks for the feedback!
merhaba . 60 & 72 v bir sistem kurasaydınız izlenme oranlarınız çok daha fazla olurdu.Bu videoda çok başarılı olmuş. çok fazla emek harcadınız.teşekkürler.
At 16.24 you check the individual cell voltage of 16 cells connected in parallel (joined by 4 strand copper wire ). How do you measure individual cell voltage if cells are still connected in parallel? It also appeared that the power supply was still connected. If the cells are still in parallel and you measured a different voltage on one cell then you have a big problem.
Yes a big problem. The only reason you would measure a difference is when the wire used to connect them in parallel has a big resistance ;-)
This is a wonderful explanation. It is most interesting the mistake you made in connecting the balancing cables. This has been my worry though I wire correctly but I imagine what would happen if such error occurs. Thanks greatly for sharing the video.
thank you for the feedback!
I am just getting started and this was a great video for me.
Hey nice video. Could you show how to wire the bms to 64 pieces of the batterys please?
Excellent. Thank you. You are a scholar and a gentleman.
thanks :) appreciate ffedback
Do you have an idea how battery's manufacturers top balance the battery cells since it takes a long time and they produce a large number of cells, is there a special machine for that or another fast method to do that ?
Thank you.
Спасибо за тест. Не согласен только с последним доводом - провода от BMS до ячейки обрезать по длине не рекомендуется. При использовании ячеек необходимо снять все наклейки с предохранительных клапанов что между клемами.
Час назад сделал заказ на 16 штук (по вашей ссылке). Собственно от туда я сюда и пришел)) Еще раз спасибо за видео и всего наилучшего!
Shorting the wires has no negative effect. Your just measuring voltages, hence very small currents..
here is a quick tip, connect all batteries in parallel initialy for a couple of hours before connecting them in series, they will all equalise to the same voltage
I was gonna say... isn't he missing a step here, which is just leaving the whole pack set up in parallel, with the copper wires, for a while to let all the cells balance out on their own? I'm still learning this stuff myself but seems this is what other DIYers do.
Best video I’ve seen so far
Thank you.
I would like to say thank you very much I thought your video was very good I found that you explained everything very well from start to finish
Cheers Anthony
Thanks Anthony.
Thanks for the video, it's very educational for a person like me without any experience.
thanks for the feedback.
@@SolarEngineering good work
Very thorough. Thank you!
Fantastic Video! Very informative and educating! Only small suggestion I have: It helps the batteries to last longer if you compress, but I think you know that already.
compress? He might know but we might not... Compress what? The cells to each other? My butt cheeks?? ?
@@ludlow7369 Your testicles
No fuse? What will BMS do if shorted?
Nice heat-insulating pad for BMS against battery!
You didn’t check the IR, why? Thanks for the video my friend
Excellent - I have bookmarked this and deleted all the other 'popular' explanations.
Glad it was helpful!
enjoying the video, one comment, checking the individual cells when they are still connected in parallel will give the same voltage for every cell. It doesn't matter which one you check, you are really just checking all, every time ....
yeah, missed this part. thanks for letting me know.
Very nice video. I like your soothing voice and good explanations.
Subscribed !
thanks
Nicely done. However, wondering why temp sensors from bms were not taped to battery wall for over/under temperature control?
Temp sensors should be attached to the battery.
Am assuming if you connect 4 cells in parallel to give aprox 12v, you'd only need a bms for 4 cells as the voltage would be the same as they are connected together
Very informative. I would say however care needs to be taken with these Aluminium case batteries. With some of them the case is connected to the -VE terminal of the cell. When the cells are stacked together if somehow the plastic wrap on the cells rubbs through it can cause a short and possibly a fire.
What is the solution?
@@fraserlynn9488 Some of the cells I have seen have plastic caps that sit on top and bottom and this makes a gap (about 5mm) between the cells. This could be re-created using some type of insulator between cells.
If I want to charge this battery then does that happen through that x60 connector that goes directly to BMS? And If I want to power up some device then should I use the big end terminals on battery pack?
I think that the the zip ties do not provide enough tension for compressing LiFePO4 cells (specs for much larger cells recommend >300 kgf). Anyway, some compression is better than no compression. Front & back plates would distribute the compression force far more evenly.
Any suggestions to build a 36 volt battery for a EZGO Electric Golf Cart ? Thanks
Why capacity tester did you use? Can you please share the link?
Excellent demonstration.
thank you
What is most economical battery in your opinion buying like you did or just buying 200 ah battery? How much $ was everything also?
This video is so informative, more so at the mistake where one wire was wrongly attachwed, however i have a question,
i have a 60V 19S BATTERY but the 13s cell group reads 0.0v , so the total voltage of the battery is less by around 3.n Volts which is failing the battery from charging but when i use a wire to skip/jump the 13s cell group and link the 12s to 14s groups the battery charges though the wire heats up. does that mean the 13s cells are dead? their connections are intact. can i disconnect the 13s and link the remaining 14s to 19s to the other series with the same BMS?
I don't think you can skip one cell in BMS. I'd start measuring and testing all cells first, also check if BMS still alive.
Can you please share the length, width, and height of the cells arranged together in the 2 rows of 8 for the 16s1p arrangement?
Thank you for The good explaining and moore, it's easy to think that you maybe are a University teacher or something...
Greatings from SWEDEN for a very PRO Channel! 😀
thank you for the feedback!
About those BMS leads, and no need to be same lenght. Is it because of the low current, because only measuring voltage with low balancing current? What is maximum balancing current at your BMS, or do you use separate balancer? Can you make same test/simulation with different leght of wires and current like 2-5A for balancing?
this BMS can balance only with ~20mA.
I have ×3 100ah batteries with built in bms on each. I tied them in parallel to make 12v 300ah. What is the battery series so i can input that correctly on my smart mppt controller
I tried charging a 12v 280Ah Lifepo battery (internal BMS not bluetooth) at 14.2 v & 4.5A and smoked my cheap Alibaba (30v/5a) PSU in 30 seconds... what went wrong?
How do you top balance and attach a 3.65v charger to each cell individually in a closed 48v battery pack?
active balancer, something like this: ua-cam.com/video/rQgOet7AH0I/v-deo.html
Thank and very nice demonstration about BMS!! Thanks
that cutoff would I guess be because of the cutoff settings i think your BMS came preconfigured for LiPo instead of LiFe and there is a huge cell voltage difference. LiFe is 2.5v - 3.7 where LiPo is 3v - 4.2v
Fantastic build, thank you for posting!
Does 3.65 volts mean 100% charge and 3.4 volts will charge the cell to 80%?
Or are 3.65, 3.5, or 3.4 volts the charging speed of the cell?
@SolarEngineering thanks for the awesome video.
Question: I am thinking of building one for myself. But I am going to slowly increase the amount of batteries. I will start with 8 batteries and then add another 8 batteries. So if I buy a 16s BMS ,can I leave 8 connector cables from BMS unattached? - as first time I will have only 8 batteries.
Some BMS supports 8s-16s config (meaning that you could use it with 8 to 16 cells), other BMSs fixed with an exact number of cells. Check BMS specs or ask the seller.
Is it important or necessary to place the cells in a tight case to prevent them from excessive swelling?
if you are planning to charge/discharge with high amps (1C +) then I'd fix cells to prevent expansion
Nice build! Very informative!
thanks
Very good explanation of balancing! Thanks.
thank you
@SolarEngineering if I make 12v out of your batteries then it will be 4p4s and 25x4=100Ah.
Do I connect the BMS same was as this video?
Also how to charge them after I configure them in 4p4s for 12v 100Ah?
A video on this configuration would be great.
Hi, yes 16 batteries for 12v batteries will be 4p4s configuration.
You'll need to use 4s bms and connect sensing leads same way as in video. You'll have only 5 leads (1 negative and then each group of paralleled cells positive).
you could see example of 2p4s here: ua-cam.com/video/Cw-5KcKCKzM/v-deo.html
FANTASTIC!!! Being a newbie this has really helped fill in a lot of gaps. I guess you used a 250watt light bulb for the 5 amp drain? For recharging the pack, you used your DC power supply though the BMS at 5 amps.. is this correct? Thanks again for taking the time to do this. Also the graph gave a perfect explanation for the need to balance! Well done!
yes, you are correct, I used multiple light bulbs to get 5A drain. Charging back with bench power supply. Thanks for the feedback.
@@SolarEngineering Thanks, a good teacher answers students questions!! Will be following you!
And that is how it is done to save have the price of a solar generator. Very good.
yep, planning to release another video soon about solar generators.
The parts with shipping for my 24V 200ah Battery is about 800.- plus bms and small parts all in all less then 1000.- € against some commercial resellers who wants to get 4500.- for the same setup.
I also bought 2x 290 Wp Solar cell for 90.- plus a mppt 200/20 with price tracker from amazon for 130.-
So all in all i can now build up a great solar system with 580Wp and 200ah Batterie for less then 1400.- against commercial seller who made me offer with minimum prize 6500 .- up to 8000.- and many weeks waiting time.
Sometimes its really worth watching videos and diy it yourself.
And if anything fails while i am on the road i can fix it myself and have a deeper understanding whats going on.
@@usurpinesusanti3149 absolutely, I agree. I build myself a powerwall that I would have not been able to afford for less than 5k.
Thank you for this valuable information. Is there any provision to bypass the under voltage cut off, as an emergency case? Please suggest.
to get power in an emergency case, you could get negative directly from battery (avoiding BMS).
Very interesting & Informative, I bought 16- 200amh lifep04 but don't know what bms is needed for 24v inverter, beginner I need help please. 🙏
BMS that I'm using in this video pretty good, here 8S version for 24V www.aliexpress.com/item/4000828229543.html?spm=a2g0o.store_pc_home.productList_8327557.subject_10
Very good thank you. Just one comment on the last part of wire lengths you may be right but the way you tried to demonstrate it is not accurate IMO due to the high voltmeter impedance it will not draw any voltage drop however that may not be the case of the BMS.
Regarding the length of the balancing wires, of course when you compare the voltage at the battery terminals and when using wires (AWG24 in your example) between the battery and the Voltmeter, you won't see a difference because the Voltmeter draws almost no load. But if the BMS adjusts the voltages between battery cells with e.g. 5 Ampere, then different lengths of the balancing cables might make a difference. Because due to Ohm's law, the voltage / power loss in the cable is I*R / I*I*R, that is, the power loss increases quadratically with the current. So that the BMS senses the cell voltages under the same conditions, I would recommend not to use different cable lengths.
I know only one active balancer that could do 5 Amps, this balancer going with really thick wires.
Most of the BMSs have passive balancers and only draw mA to balance cells.
But you are right it's worth mentioning that equal length balancing wires could be required for some applications.
Thanks.
You are correct most BMS only draw 65 MA but that will cause a voltage drop of a few MV but the BMS is measuring MV and can cause the BMS to not balance correctly if the leads are not the same length.
Grear video! Thank you for your work!
How much power can this batery pack deliver continously? How many Amps?
For your large battery bank in the toolbox, did you use this brand BMS?
I did use Chargery BMS, but burned it doing some tests. Right now I don't have BMS on my bigger bank, just an active balancer.
What kind of load are you putting on a battery bank such as the one in the video? I’m looking at starting to build 1 battery bank at a time to help power my shop. Do these style batteries have a good life span on them as far as daily use and overall life?
Thank you
I'm just using 48V inverter (here is example: amzn.to/3seiyiV)
I haven't tested this exact batteries for long time, but in general LiFePo4 can 2000+ cycles before it's going to drop to 80% of original capacity.
what is the nom charge voltage? in a 12v system? max is 14.4 so should it be charged at 13.8 or 14.1???
what size is the busbar? if 50 amperes does the busbar need to be thicker?
Hello, thank you very much for the super instructions that I am recreating. The parts are all ordered. My question: Can two such, completely identical systems of 16 x 3.2 V 25Ah LiFePO4 batteries each with a BMS 16S Lifepo4 50A be connected in parallel, so that 1 large battery with 48 volts and 2,560 Wh (= 2 x 1,280 Wh) arises?
Vielen Dank und viele „greetings from Germany”!
After getting them to 12 volt would you than still be able to connect the second battery bank in parallel to the first battery bank? If they both match in Voltage and amps?
I have some Honda Insight cells in there original 18 cell cases, I would like to make 4S4P 16 cell 14.8V packs to use in my RV. I'm pretty new to battery building and was wondering if you might have an opinion on what BMS to purchase for this application? I will be building 4 packs and wiring the in parallel. Thx for any advice. Love your videos, they make the most sense of any on the internet to me.
I like this BMS: ua-cam.com/video/k8Wkg-tVnx8/v-deo.html
Also recently got Daly BMS (last video on the channel), but haven't tested it yet. It looks promising, going to perform tests soon.
@@SolarEngineering Thanks for the response!
What a Lesson professor! Cheers from Brazil!
)) thanks