Lithium batteries for beginners. Step by step: balancing, assembling, capacity test. LiFePo4 DIY.

[@robinhughes-jones4034]

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.

[@SolarEngineering]

thank you for the feedback, appreciate it.

[@fvanzlr]

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.

[@SolarEngineering]

yeah I missed that step, thanks for letting me know. And thank you for kind feedback.

[@lilwwwlil]

))) 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 !

[@jdickson242]

Yep lol

[@daveincanada4794]

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!

[@axoidmax]

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.

[@trezzadeng5839]

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.

[@leandrofranceschi322]

The best splaning ever made. Congratulation! Very Good Work man!

[@Absfor30]

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.

[@SolarEngineering]

Much appreciated!

[@RandoRaf]

This was the best explanation of how to build. You explained each step vs just rushing through.

[@SolarEngineering]

thanks!

[@pewpewwithtodd8077]

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.

[@SolarEngineering]

glad it was helpful.

[@hafeexius]

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.

[@SolarEngineering]

nice, glad that video helped!

[@johanwagho5257]

I'm on exact that same path with the same findings

[@hadisiswantoro2777]

Your description is very good. You explain step by step what must be checked before entering the next stage.

[@SolarEngineering]

Glad it was helpful!

[@lmorchard]

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 :)

[@SolarEngineering]

totally unplanned, glad that I didn't burn BMS

[@whazzat8015]

@@SolarEngineering You showed why it's important. Bravo!

[@TheBluebird65]

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.

[@WikkidDJ]

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

[@calvinflager4457]

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.

[@SolarEngineering]

glad it was helpful!

[@ivanhoe6366]

Thanks for taking time to share your knowledge.

[@randeb1974]

Looking forward to working this out. Randy. [e-mail]

[@DStein-jn9ls]

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.

[@SolarEngineering]

appreciate your feedback

[@BriTube007]

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.

[@pieterh2058]

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?

[@LoekiNL]

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.

[@ianworthington2324]

@@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.

[@belspace]

The best explanation in youtube on DIY battery pack ! 👍

[@SolarEngineering]

appreciate your feedback

[@whazzat8015]

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

[@SolarEngineering]

really good points, thanks

[@paullazo19]

Very thorough. Thank you!

[@Base612]

"OK. I don't see smoke." LOL This was an *excellent* video. I learned a lot. Thanks so much.

[@SolarEngineering]

Glad to read that! Thanks.

[@SkypowerwithKarl]

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.

[@SolarEngineering]

good to know, thanks for the advice.

[@luckydogfarms]

Always learn more when I watch your videos! Thanks, J

[@SolarEngineering]

thanks!

[@sxmplx5356]

Wow I'm learning more from this! May you live longer SIr!

[@SolarEngineering]

thank you for the feedback!

[@johanwagho5257]

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 🙂 🙂

[@PeterHelenefors]

Thank you! Appreciate you really explaining each and every step so thouroughly.

[@erdenertorer]

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!

[@SolarEngineering]

that's correct, missed this step, busbars should be disconnected.

[@TK-123]

Top shelf instructions. Thank you for your clear, and concise directions..

[@SolarEngineering]

your feedback is much appreciated.

[@om617yota8]

Fantastic build, thank you for posting!

[@TeoCorrales]

Thanks for the video, it's very educational for a person like me without any experience.

[@SolarEngineering]

thanks for the feedback.

[@engrevergreenifeanyiohaegb4188]

@@SolarEngineering good work

[@gaetangagnon5913]

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.

[@SolarEngineering]

glad it was helpful!

[@davekendall4698]

Very impressive & informative I liked the info in the drop down too. Links/time codes etc. Got my mind working overtime now.⚡️

[@SolarEngineering]

thank you for the feedback!

[@MrMastercc]

brilliant step by step video tutorial. well done

[@fatauntie]

Thank you for your video. Great information that is easily understood. Well done! Looking forward to your other videos.

[@omaha42000]

Excellent. Thank you. You are a scholar and a gentleman.

[@SolarEngineering]

thanks :) appreciate ffedback

[@MrRalph301]

Thank!, you very well explained,it claered many questions I had.

[@MadStylesGooffy]

Nice build! Very informative!

[@SolarEngineering]

thanks

[@elwynneri1891]

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.

[@SolarEngineering]

glad it was helpful!

[@ajgonzalez9926]

Hey bro how long take them to ship to you?.

[@safewilliamp.assist.tec.8203]

Thank you very much!!! The best explanation that Ive ever seen!

[@SolarEngineering]

appreciate your feedback.

[@mohsinrazaengr]

Excellent demonstration.

[@SolarEngineering]

thank you

[@murzello]

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!

[@TK-123]

Shorting the wires has no negative effect. Your just measuring voltages, hence very small currents..

[@neliosamch3195]

And that is how it is done to save have the price of a solar generator. Very good.

[@SolarEngineering]

yep, planning to release another video soon about solar generators.

[@usurpinesusanti3149]

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.

[@neliosamch3195]

@@usurpinesusanti3149 absolutely, I agree. I build myself a powerwall that I would have not been able to afford for less than 5k.

[@dharmasagarpatil8485]

Thank and very nice demonstration about BMS!! Thanks

[@viko2812]

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.

[@SolarEngineering]

спасибо за совет и за отзыв.

[@jonathanneethling]

Best video I’ve seen so far

[@SolarEngineering]

Thank you.

[@ionutcatalin525]

Nice explaning, whery good video!

[@AandABlackmoore]

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

[@SolarEngineering]

Thanks Anthony.

[@charleswhitehead7441]

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.

[@juergwyser6520]

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?

[@SolarEngineering]

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.

[@princeeze9414]

How can I get this product

[@mfrutos]

What a Lesson professor! Cheers from Brazil!

[@SolarEngineering]

)) thanks

[@lucianpopescu1786]

Very nice build. Very organized. I like it. Big thanks for the information

[@SolarEngineering]

thanks for the feedback!

[@meganote]

Very good explanation of balancing! Thanks.

[@SolarEngineering]

thank you

[@toolate6971]

I am just getting started and this was a great video for me.

[@chukslis3486]

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.

[@SolarEngineering]

thank you for the feedback!

[@izemanevobike]

30:00: "I don't see smoke ...". Sounds so familiar to me :)

[@PawlSpring]

I am about to tackle a similar project with 48(!) prismatic cells. This video is perfect timing 🙂

[@SolarEngineering]

48 in series??

[@PawlSpring]

@@SolarEngineering Not quite. Ultimately a 16S3P, but they have to be top balanced.

[@SolarEngineering]

@@PawlSpring ah I see, I have same bank 3p16S. kzbin.info/www/bejne/iHPCgJJrhdWpbck

[@andreasv5517]

What resistor to precharge is used? Top explained, to the point! Thank you!!

[@SolarEngineering]

For 48V 30-60 ohm will work thank you for kind feedback

[@701theboop5]

Excelland job showing how it all works !!

[@joatmofa0405]

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!

[@SolarEngineering]

haha, I wish your words become a reality :) Thanks for the feedback.

[@RapidCRM]

Excellent - I have bookmarked this and deleted all the other 'popular' explanations.

[@SolarEngineering]

Glad it was helpful!

[@mbu745]

Good video. I learned a lot. Thank you very much.

[@SolarEngineering]

Glad it was helpful!

[@tarekabighanem3125]

Excellent work and explaining

[@SolarEngineering]

Glad you liked it

[@dantronics1682]

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

[@wanderingzythophile9083]

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.

[@MarkEatmon]

Thank you doing this video. Even your mistakes are good for this video

[@SolarEngineering]

yeah, I thought it's a good thing to leave in video, to see how easy is to make mistake

[@tylerb9808]

I'm glad you included that overlook. It shines a light on how important it is to double check things. Even if you fried your bms, the lesson would be long learned. And I really appreciated the texts on the screen as you moved along. I made notes! Helped me understand C ratings a lot better. Thanks!

[@peshawarzulmi6451]

Very professionally explained! Thanks you.

[@SolarEngineering]

thanks for the feedback.

[@leandersmith6184]

Very good and clearly explained. Thanks you got yourself a new subscriber.

[@hampusjalkling2462]

Great video, got the info I was looking for. Thanks a lot!

[@SolarEngineering]

Glad it was helpful!

[@mar1video]

Very nice video. I like your soothing voice and good explanations. Subscribed !

[@SolarEngineering]

thanks

[@harrydavis6461]

Looks great. Thanks for the video.

[@SolarEngineering]

thanks!

[@abelramos8652]

You didn’t check the IR, why? Thanks for the video my friend

[@kevinandersson4882]

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! 😀

[@SolarEngineering]

thank you for the feedback!

[@GeekGarageDK]

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

[@AsailingDIYlifechannel]

Lovely - thank you so much for this very in-dept description

[@SolarEngineering]

thanks!

[@spammebabe]

Solid info my friend thank you very much for that!

[@runneryg]

I LOVED THE VIDEO AND I LIKE THE CELLS A LOT I WILL BUY THIS BATTERY AS I THINK THEY ARE THE BEST ALSO TRY AND BUY THE THINGS I NEED AND GIVE IT AGO FOR £500 OR JUST UNDER 24 VOLT 2OO AH IS WHAT I AM LOOKING FOR PLUS I BE SAVING FROM BUYING IT ALL SETUP. I AM SURE I WILL COME TO THIS FOR MORE INFO IN THE FUTURE TO SHOW ME HOW TO SET IT UP CORRECTLY LOVELY EXPLANATION ON HOW TO SET IT UP.

[@mark_osborne]

Fantastic job !

[@MrGarda42]

OMG I LOVE that accent!!! 🍻 Great video mate ✌️✌️

[@SolarEngineering]

appreciate your feedback!

[@michaeldodson879]

Excellent battery build video.

[@SolarEngineering]

Thanks 👍

[@briansaul7352]

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.

[@pieterh2058]

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 ;-)

[@The.2.Minute-Man]

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 )

[@waynewilliamson4212]

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 ....

[@SolarEngineering]

yeah, missed this part. thanks for letting me know.

Grear video! Thank you for your work! How much power can this batery pack deliver continously? How many Amps?

[@geeuk]

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

[@SolarEngineering]

appreciate your feedback

[@Jimdandy1958]

Very well explained and done! I made sure and gave it a LIKE!...

[@SolarEngineering]

thank you

[@princeeze9414]

Nice work ❤

[@scotthenderson4376]

Very nice wish I knew were to buy all you need to do this. I need to build a 48v 200ah battery to replace my 48v 400 ah lead acid pack

[@SolarEngineering]

here is bigger bank build: kzbin.info/www/bejne/iHPCgJJrhdWpbck links in the video, feel free to ask question about tools/parts purchase

[@muharremcan2662]

merhaba . 60 & 72 v bir sistem kurasaydınız izlenme oranlarınız çok daha fazla olurdu.Bu videoda çok başarılı olmuş. çok fazla emek harcadınız.teşekkürler.

[@reyonwilson9334]

Hey nice video. Could you show how to wire the bms to 64 pieces of the batterys please?

[@peter572]

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.

[@aguswijayagurumu]

Priviet. Very good explanation. Thank you

[@SolarEngineering]

You are welcome!

[@londel1767]

great video, very helpful

[@usurpinesusanti3149]

Thank You for this very good video, its exactly what i am planning to do, already have ordered cells from China an BMS which looks almost exactly the one in your video. Very good explanation and very helpful indeed. I feel now much better prepared to do it right and i am not a professional at all. You did a very good job with this video.

[@SolarEngineering]

appreciate your feedback.

[@marioescalona1640]

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.

[@sygad1]

very detailed, thank you

[@SolarEngineering]

Glad it was helpful!

[@leoclarkin5944]

Thank you very helpful and educational!

[@SolarEngineering]

you are welcome!

[@ppi57]

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?

[@hansdybka1331]

I have learned so much from your presentation, thank you. Excellent presentation of data with the discharge rate chart...helped me understand the issue exactly, also pointing out the different battery configurations possible...you covered alot and helped me immensly.

[@cvdheyden]

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.

[@ludlow7369]

compress? He might know but we might not... Compress what? The cells to each other? My butt cheeks?? ?

[@cvdheyden]

@@ludlow7369 Your testicles

[@roliki1890]

отличная работа

[@sunnyhongkong]

Other people's just play but you are real guy

[@antonkireev4098]

Отличное видео. Спасибо.

[@SolarEngineering]

спасибо за отзыв.