What is a Battery Management System / BMS?

[@jedics1]

You explained BMS better than anyone else Ive come across, thanks.

[@sreekumarUSA]

Hello Martin, I have been watching many many instructional videos regarding charging Li-Ion Batteries and BMS around it. But, none of the instructions were able to explain as elaborately and as the simplest way, you have explained. Your teachings just went into my brain and I could understand the basics of charging the above cells. You are a great Teacher. Thank you.

[@gideonlapidus8996]

Your explanation is great Martin. Really enjoyed watching this.

[@billerwin7770]

Thank you very much for providing what I believe to be the best intro to BMS video on KZbin. Clear explanations, no hype. I definitely benefited from your video!

[@JulianIlett]

Thanks Martin. Nice introduction to battery management systems and cell balancing. Looking forward to your review of Dacin's SBMS.

[@proyectosledar]

totally agree with my friend.

[@mjlorton]

Julian Ilett Thanks Julian.

[@devendrayadav7409]

@@proyectosledar eying cc to get your own home and I will have the same as

[@digitalwasting]

Your video is so helpful in getting me brain actually understanding BMS now :) Thank you so much !!!!

[@mjlorton]

Miguel Bodega Thanks for the feedback.

[@randall1fc616]

Yes, I agree with S.Kumar. Lesson taught in a clear and concise manner, very easy to understand even for someone like myself, who has zero knowledge. Thank you, Martin. Keep such good videos coming. Cheers!

[@quintinkruger9103]

I am a software engineer that studied electronic engineering. Figured I wanna get my hands dirty with some electronics. Going to build my first electronics project which is a solar powered battery bank. This lekker video will definitely help me ! You are a great teacher !!

[@udai4k]

simplifying things and explainign is an art, and only peolpe who nderstoodthe concept can do that, you are one such expert! thank you

[@vigneshwarrajc6629]

Hi Martin , understood the working of BMS in one shot from your video even for a person who is new to batteries and related electronics like me.

[@jimmyday3984]

I've been watching a lot of battery videos with reasonable comprehension, but everything you said was so clearly explained and well presented I understand it all perfectly now! Thank you, you're a champ :)

[@valhumble1609]

Thank you for sharing your knowledge. And your edited presentation is very well done.

[@MrGoogle87]

Great video, very easy to understand! Better then a video just showing the wiring =)! The drawing was perfect

[@nrgraff]

It's been several years since I studied physics, so I'm pretty rusty and never got too advanced. But I was able to follow and I learned a lot, so thanks! I just got an electric bike with a big lithium battery, so I was curious for that reason. Good to know a BMS is a safety feature in addition to a way of extending the battery's lifetime!

[@alexfladung]

Love the way that you explain things in a way that even I can understand. Thanks!

[@johnbrevard5966]

Amazing!... I learned more here in the first 2 minutes than anywhere else on KZbin!!! in a week !!!

[@MLFranklin]

This is a very helpful description. Thank you for sharing it.

[@smge1lc]

Awesome presentation; well spoken with great illustrations.

[@dalendru]

Excellent video. Thanks for the clear description!

[@MaxGoddur]

Thank you a great job on the information and delivery of the subject matter video.

[@Hopeless2013]

Martin you are an outstanding teacher very good presentation of the BMS and how they work keep up the good work and I hope to see a presentation of the Lead Acid Batteries because that's what I use in the e- bike that I have. I got me one of those e-bike kits conversion kits and it's being working good but the batteries are big and heavy. I going to buy the some Tender Lithium Iron Phosphate Batteries and I would like to know if they do have a BMS within the battery.

[@cptglen]

Wow, Thanks. I've been converting my JarCat Catamaran to electric, and have really feared treading into the Lithium ion battery packs. I've got 2400 watts of AGM's, at 210 lbs. 660 watts of solar, and an MPPT charge controller, but, I'm really looking forward to the conversion (and understand it a bit more) and the weight/power savings. Thanks again. Really good Job.

[@Avionics1958]

Excellent video. Although i have many chargers and balancers to charge up my batteries i have one charger that only charges through the balancer wires and that i can see now that charges each battery individually which is why i always liked it as the batteries always charge up well balanced.

[@poovertech9368]

Good Tutorial ，some suggests below : 1 - 18650 batteries whether in series or in parallel into the battery pack is a certain requirement for the battery, especially when used in series, the battery voltage, internal resistance, capacity as much as possible requirements, the voltage difference of 20mV, internal resistance difference of 10 milliohm, capacity The difference between 20mA is reasonable, 2 - especially the batteries with too much internal resistance connected in series will cause fever, and serious will cause smoke to catch fire. Be careful! 3 - There are also battery packs to pay attention to the problem of short circuit. Note that only high-temperature adhesives, barley paper, nickel and other accessories are used to avoid scratching the battery skin and scratching the skin. Dont suggest to diy the lithium ion battery pack if you are not known all these knowledge of battery balance management detais .

[@New_World_Disorder]

Excellent video! Thank you for the clear explanation!

[@electrodacus]

Great video Martin. I can not wait to see the review on my SBMS. It will probably be one of the most detailed feedback that I will get about the SBMS. I'm already thinking about the new version and all the feedback from SBMS users is extremely important.

[@The22v10]

Awesome, BMS. a technology all its own... Looking forward to the next one with the Solar controller..NICE work Peace

[@daniele_go]

Hi Martin, this video is by far the best I have ever seen on BMS ! Thanks a lot!

[@tomasstrom1343]

Thank you! Trying to decide if i dare to buy a complete imiev electric car battery pack ( the car was in a crash so i can buy the cells quite cheap ) but i have so many questions about lithium bateries. Thank you for helping me understand the general idea behind bms! Tomas/ sweden

[@infopluschannel]

very clear and good explanation. thx u

[@adam1273123]

Great video. Finally got my head around battery balancing.

[@mjlorton]

Adam Al My pleasure, thanks for the post Adam.

[@stevenkmckendallsr1169]

Great video. Can you pleas provide a link to the the next / specific video (i.e., specifically referenced, at the end of this video). Thank you.

[@focusonevideos]

excellent explanation. so my new LiFePo4 died after 2 months living outside. coldest temp 14°F. Presume the BMS failed as 12V battery was .2v when i tested it. charged back to 2.0v overnight. Will a new BMS work to bring it back to life ?

[@7328971]

thank you.I test electrodacu's sbms4080. for some days as solar charger and on my ebike too.it's exactly what I need for my precious lithium cells. looking forward for the review!

[@williamrosar2370]

Thank you now I understand the importance of balancing the cells

[@rashidkhan-pd8cf]

great explanation.many thanks

[@ElectronFunCom]

Great video Martin! I finally know what BMS is all about. Thanks for sharing!

[@mjlorton]

ElectronFun.com Thanks. You have a great channel. I hope you find time to do more videos. I have added it to the list of channels on my home page. Cheers, Martin.

[@ElectronFunCom]

mjlorton My regular job is quite demanding, but I'm doing what I can to start making more videos. You are one of my favorite KZbin creators and I would never have expected you might add my tiny channel to your list - thank you so much!

[@sankalpshukla2192]

Thanks Sir,,,🙏Can I charge 4 Li ion mobile batteries (also 18650) by Laptop BMS Circuit it also have 5 wire as you shown...🙄🙄🙄

[@scepticalbudha2553]

Hi. Very educational video. Thanks. Im trying to put together a battery pack for my motorcycle with each cell 2.1 amps. 5 rows in parallel and three cells in series to give 12.6 V fully charged at 10.5A. As Im a newbie, I do not know which BMS I should use and how to connect. your assistance if possible will be highly appreciated.

[@TheSn1per]

I know this post is quite old. But perhaps you can help. I have a 5S setup. and the same Balancer your using @15:00 mins. But I cannot find any schematic of how to wire. I lookat at your video many times trying to see how you have the batteries wired up. can you poss show a wiring schematic of the pins on the side of the unit? or or? Thanks - Sam

[@seshachary5580]

GREAT EDUCATION tHANK YOU REGARDS

[@neddypong]

great tutorial as ever,thank you. Q. I have noticed that on power tools the balancing wires are fed into the power tools trigger via the battery pack , Why would this be when the balancing leads are for charging? Thanks

[@marcotulio-analogchannel306]

Hello Martin, where can I find the bms you used in the video? Thanks for share!! Túlio

[@nieuwegeljo5645]

Great video with excellent explanations! Thanks.

[@junesarol1782]

Good day. Is the ah of the bms matter? Like for instance i will use a bms board with 35ah but in actual ah of a battery is 38 or 45 or 60 ah.?

[@jackmenino9654]

Hello, really great video. I just bought a scooter and this scooter has a 52V and 22.4Ah. How will I know if all the individual cells are charging equally. I think the battery comes with BMS . Is there a device I can use externally to check if cells are charging same level. Thank so much.

[@Mananassy]

Very good video, thx . I have a LiMn battery that I bought as new but I ve never used, which was stored during one year. It does noy want to take charge from its charger now. Can you help me to restore it?

[@Mazel_Tov_888]

great job! I'm a lot smart now which may not be saying much based on where I started from!

[@nesarag9546]

thank you so much... it is very much interesting and easy to understand.

[@jimmatrix7244]

Is it possible to replace a laptop's battery protection circuit which is locked by a code or simply use a new circuit?

[@canlelola]

I've been looking at building a small battery bank myself and have ordered a few BMS's off eBay for Cell's between one and six to play around. I have been thinking if using the single BMS's will work in a large battery pack, but I am worried about a the battery's trying to charge one another anyway with that kind of set up.

[@andonrangelov8844]

Very nice video Martin, thanks for it. I have a question, I want to make an 18650 battery pack of 4 batteries in series and I wonder what is better: to have Battery Management System for the hole pack or to have 4 Battery Management System for each battery in the series?

[@mauritsschoonderwaldt676]

for 4 cells it really doesnt matter, so it really doesn make sense to have multiple bms units. just use one.

[@MaxGoddur]

Off I go to see if you have any more videos on BMS and its make up. It would be great if someone showed a schematic of BMS for DYI.

[@kdknitro]

I work on boats that have inverters in them, that wind up doing exactly what you describe. You get situations where the chargers arent "smart" enough and wind up destroying big battery banks that are tied in series. You get one batter get low on water or get a bad cell and the charger on the inverter only sees nominal voltage and just keeps dumping current into the bank until it over charges the good batteries. Ive always wondered why they dont put this type of technology into these inverters.

[@virgilionavarro1009]

I have 5kw solar panels without power bank, I have 10 uxh125-6fr. Can I use these as a power bank.Do you have any idea how to set up the system ?

[@waloooody]

Hello martin ... my question is . Can i use 18650 laptop cells with deferent capacities with BMS ? Such, 19650 mah with 2200 mah With 2000 mah .. its 3s pack by the way

[@emreiris114]

thank you so much. I have a question Suppose that we have 3S3P battery pack and we balance first 3 series cells of first parallel line. Do we have to do it for other 2 parallel line?or is there another way?

[@alloycrow917]

Amazingly explained. Thank you.

[@dickebikefan3050]

Thanks Martin for your explanation about BMS. Your Video is very helpful for me to make an E bike battery. Ik have some knowledge about electricity and now I´m busy to make a battery for my E bike. Can you advice me about a good BMS with the next specifications 36V-11,4Ah (40 cells). I really don´t know which one I have to buy!Greetings from Dick (from Holland)

[@Do_the_Dishes]

I have a question I hope someone can answer. I just bought some LifePo4 batteries for my off grid system. 4 - “KiloVault” 3600 Wh each. They have a built in BMS and I want to maximize longevity. I plan on only ever going down to about 25% DOD. So my question is about the top end of charging. Is it ok to only charge them to say 99% state of charge each time? Or do I have to worry about some type of finishing charge like lead acid? Thank you in advance.

[@linuxxxunil]

I'm not an electronics person by any stretch of the imagination but am intrigued by the subject and have u and Julian subbed. I rarely sit thru a video out of frustration to my lack of retention (what I deem learning) but this was spot on. I wonder if there was bms systems in the old blackberry Phones or chargers? my 9320 curve lasts all day long and yes i realize there aren't many apps running.

[@mauritsschoonderwaldt676]

there are. if there werent, it would explode.

[@ForensicCats]

Very nice video, thanks for your time.

[@bullguy112]

very good explanation,thanks

[@jeevankg1]

Thank you Martin, very useful.

[@mjlorton]

K GANESH RAMA RAO My pleasure, thanks for the feedback.

[@andrewzanas9387]

Thank you, sir. Great information!

[@Lea-ww9hf]

Oh just the video I was looking for! Thank you very much Sr!

[@guiterman6263]

Hello dude I'm building a 24 volt 7p 7S battery for my ebike could u tell me a good Bms I could get for it thanks and keep up the good work dude

[@szentmihalyiautodiagnosztika]

A very helpfull tutorial, now I get it ,thanks Martin

[@yashwanthl1768]

Thanks for sharing your knowledge I have questions with respect to cell balancing please help me 1.when this cell balancing will occur is it when charging the battery or when any cell goes more then rated voltage. 2.As in the video in order to enable the cell balancing you took cell to its highest voltage level in real life it may leads to exposion correct me if am wrong 3.can you please explain below scenario if am following passive cell balancing where a resistor is used to discharge the excess voltage of cell I have 3 cell of maximum voltage that it can store is 5v nominal voltage is 3.3v 1st cell is at 1v 2nd cell is at 3.3v 3rd cell is at 2v Here when cell one reach 3.3 v the second cell voltage will 5.6v which may leads to exposion In all the above I have connect the cell in series

[@paguliukas]

very good explanation thank you

[@roshanjohnson9482]

I have a doubt. what if one or more sub packs are dead? SInce the bms balances each sub pack by bleeding it to the level of the lowest sub pack will it also kill the rest of the sub packs? Or does it have a mechanism to cut off that particular sub pack from the rest of the battery while charging and balancing?

[@olliohls1846]

Superb explanation! Thank you :)

[@mountainman4410]

Amazing explanation. Such a simple to understand breakdown. Thank you for sharing your knowledge with us. I have a question about the equalization charge of lead acid batteries. When lead acid batteries are hook in parallel and series in a large solar system bank, is an equalizing charger able to effectively balance the cells? Or would it be better to isolate each battery and equalize them individually?

[@ttgeek]

Do you have a name or link to the balancer you are using in this video?

[@Praveenrareboyz]

crystal clear explanation

[@enkhtuvshine]

Amazing video thanks.

[@lishapatel5361]

sir can u explain block diagram of the battery management system ... and how i madethis BMS...

[@Red8ify]

Very good video. Thank you!

[@Gallardo6669]

Wow,outstanding video...!!! Thank you so much 😃

[@anandagaming2171]

what is the required bms for 14.4v 30ah lipo battery pack ?

[@robertcalkjr.8325]

Good job - thanks Martin.

[@charlescho]

Great video. 👍

[@user-uz2bk1hs4c]

Do your device support 10s ? If I already have A bms on thr battery and I want an extern display to monitor like this how to do ?

[@natezei8230]

Great and so useful ,

[@navneetccna]

can you please explain JST connection and how we can use it ?

[@ivanreynoso3849]

Can a BMS work as an ideal diode for batteries batteries in parallel ?

[@donaldhenke2750]

good job explaining., thank you.......

[@ash0787]

good video sir

[@readyhouse]

how can the BMS tell the difference between the voltage of the charger and the voltage of the battery pack? as in the diagram they are connected together?

[@crazyexperiments4815]

I have a 6s bms on a 6s (22,2v) lipo battery but i don't know what the maximum voltage that i can put into the bms. Please help!

[@BP-sf7br]

amazing explanation...

[@robviolin1]

Very, very helpful, thanks.

[@dylanc9275]

So say i want to build a power wall. Does it make sense to run all my packs in 48v or should i run smaller packs say in 12v and then run those moduals in series.

[@baronvonlimbourgh1716]

The easiest/cheapest way to do it is to use the device he is using for balancing. Wire every set up with the wires and then balance the set to your minimum voltage you will be using. Lets say 3.2 volts. Do this with every set in your battery pack. Now all single cells in your entire battery are discharged and all at 3.2 volts. Now charge the battery to your max voltage, say 4.1 volts. Once done charging check every set once again by plugging every set in one after another and they all should be balanced at 4.1 volt. Now all induvidual cells should stay within range and balanced over time. Just plug every set into the device every 6 months or so, or 100 cycles for example, to check if they haven't drifted apart to much. They should now stay ballanced to eachother to within very small margins naturally. Especially when using houndreds of cells it can become a nightmare as well as very expensive to realtime manage every individual cell in a battery. Doing it this way you keep it simple and if you just check every once in a while you will be able to catch any issues before it becomes a problem. And all you need to do is just wire up every set that is in series with the cables so you can just plug it in when you want check up on them.

[@gregkingston2087]

I wasted $3500 on 12v 300AH Lifpo4 Lithium batteries for my campervan I didn't install a BMS and after two years the batteries all swelled up except three of them. The three that were not swollen don't show any volts at all but the other swollen 9 still hold 3.2V each. Being swollen are they stuffed? I have replaced with a AGM. But I have another camper with Lithium lifepo4 24V 200AH and there are 32 cells at 3.2v each. I have had them in for a year now and still seem to be ok but NO BMS. It sounds like a very expensive job to BMS this set up.Or is it already too late to set a BMS up as they have been in for a year without BMS? Any recommendations? thanks

[@bengrobben2582]

its not that expensive to get a bms. just buy a smart bms with Bluetooth. so you can see on the app if there is any cell not the correct voltage. but balancing wil not do alot. because of the insane high AH you have. a bms draws about 30mah per cell. so ballancing a cell will take super long. but when you instal the bms you can see it on the app. so when a cell is a lot lower or higer than the rest. you can manually charge or discharge that cell.

[@arunps1584]

Very helpful, thank you

[@normnilsson7208]

excellent

[@oogie-boogie]

so in parallel is better? you wont have any probs?

[@keokio7]

excellent information

[@uavscientific]

I am sorry to disrupt the common point of view about balance charging Lithium Polymer batteries, but it matters very little to balance charge a LiPo battery. What matters to the longevity of the battery is how you discharge it. During a normal application one will discharge the battery at 20-30C. If a battery is unbalanced, it does not matter how nice you are for balance charging the battery. When you discharge it at high rates with impedance differences between the cells in the battery pack, you will only damage it more. Simply put, if your LiPo batteries have impedance (resistance) differences between the cells, which will give you the signs of an unbalanced pack, then it is too late and there is nothing you can do. Nothing will make it better, including balance charging. From that point on, every time you cycle the battery, regardless if you balance charge or not, the cells with the most resistance to charge will effectively overcharge and kill the good cells in the battery, and when you discharge the battery, at high rates the resistive cells will also over discharge the good cells causing more damage. The only thing that will save your battery once the cells become unbalanced is to use a balance discharge circuit, and those circuits have not come to market in an affordable way yet. This comment is for Lithium batteries only. Lead Acid can recover a bit better from an unbalanced state than Lithium.

[@MT-nx8ln]

Dear, i have a E bike batterij 36V 13 Ah (don't Know the capacity of the individual cells). Fully charged i am measuring 40.7V. After driving+/- 30 km the bike is cutting off at 37V (action radius should be +/-90 km). This is going on with Bafang motor bike but also with Tongsheng motor bike (so problem at battery level?)! On the battery capacity level indicator i have 3 green LEDs remaining (so battery about 70% capacity) After measuring different packs of batteries i measuring between 37 and 37,2 V. What can be the problem? Thanks for your reaction. Greetings

[@noobz5056]

That is definitely the problem in the battery pack. Did you build the battery pack yourself? How many parallel connections are in that e-bike battery pack?