Do you NEED a BMS for DIY Li-ion Batteries?

[@fransahm1956]

I just ordered my first ebike and I am getting ready to build my old bike with a front wheel kit. Now I am considering building my own battery for that project. Thanks to your channel.

[@jeremydewayneellis]

Great video micah "to bms or not to bms"😂😂 my favorite part!

[@bp5082]

100% of failures I have had have been due to the bms. E boards, e bikes, builds or that I've bought. When you buy a battery pack eventually it fails let's say 3 months. You will think you got it wet and you buy another thinking you were at fault then the new one fails. Eventually you will get really mad, then you take off the shrink wrap check all the cells, everything seems good then you inspect the bms and you see aluminum oxide and sometimes burns. At this point you get really angry due to the money you have spent. I don't think anyone has designed a pack that cells can be released and put back quickly and charged completely. Anyone who reads I hope it helps. It's not your motor, it's not your speed controller, it is the bms. If you are loyal to bms units you will be walking home a ton. I highly recommend you not use a bms and charge each cell individual with an 18650 charger-i have 3 exakt chargers and I can charge every cell to its fullest capacity quicker than with a single charger and pack. E bike school has great Vids if your just starting and I hope this comment helps someone, I would have save a painful large amount of money if I had read a comment like this one. Cheers

[@gabriellaalvarez2527]

Great video! Thanks for teaching about the intricacies of BMS’s

[@JUANRAMONROBLES]

Tu usas ebike?

[@OH8STN]

👍👍👍 this was an excellent video. The truth is Always Somewhere in the center. I almost always use BMS, and I never rely on cheap Chinese variants. I think a BMS makes charging away from home much easier. For example if I'm charging with a solar panel and charge controller, maybe a BMS will take care of all of the issues my home charger would solve for me. I think if I were discharging on the road and charging at home, perhaps there wouldn't be any need for a BMS. I do like the over and under voltage protection though, that's critical functionality.

[@tubularap]

Yes, that is a good answer for when a BMS is neccessary : On the Road. Like on an ebike with solar panel trailer (which I'm building) you cannot balance charge during a trip. Sometimes I will plug in a wall outlet, solar charging goes on all the time, and I will use regenerative braking too. The BMS inside my packs will take care of the hassles that do not seem a big deal when you're at home.

[@TheGbow0704]

Thanks for all your vids on Lithium batteries, I bought your book on Lithium batteries and it has been very helpful

[@Phoenix540]

OK, now what about BMSs on series/parallel battery packs, is it a special type of BMS or can you use a standard BMS?

[@Gracinda80]

You would be amazed at how many EV owners I know who think they understand what a battery is and how to manage it properly when they talk to auto electricians (many of whom are also quite inept) but totaly miss to understand it! This is the perfect video for all of them, EV owners and EV technicians alike. I would just add some graphics and schematics and voila!

[@praxabora1]

Hello, Thank you for this helpful video! Can you tell us a few good commercial BMS options for 12V batteries, please?

[@tomodeable]

Great work Ebike school, all/any of your book will be of great help to me. Pls continue the good work you are doing.

[@kyfish-on3203]

The only video I have seen with the most important information on it! DIY batteries is not for the faint.... I need your help with the ebike 48v lead acid setup, popping and arching upon connecting, what is the best way to eliminate the risk of failure?

[@martinpetrov8801]

Good video mate, verry nice!Thank you!

[@luongmaihunggia]

If battery = series Answer: yes If battery = not series Answer: no

[@VerticalWit]

You are doing god's work

[@loganf9701]

@@VerticalWit amen

[@EmperorThePro]

hahahahahahah thanks

[@09kenxgamer31]

Sir sure about that?

[@melvinjansen2338]

What if you need both?

[@westbourne1956]

This is a great Video, You explained it so well, I often wondered the two differences ,I was on the same page as you but for me explaining this to a friend it was difficult . So I just sent him your video. Great job

[@R.B.forMER_S.]

📹 Do a video on how to wire up Two BMS's👀

[@RogueLegend999]

Yes, please i would like to see that too

[@turbotim9009]

New to ebikes, I have question for you. Why would you need or use two BMS’s?

[@JBattler]

Do one yourself or send money...You might want to add 'please'. These guys do the work and we get to learn. Sure they may make money from it somehow, but social norms are still at play.

[@bhuvanmishra13]

Such a wonderful Video. Thanks a lot! :)

[@رياضحمادنة-ش4م]

Thanks for everything 👍👍👍

[@alfredfeuerstein9517]

The safest way: use a bms AND use a voltage checker for each bank to ensure your bms is working!

[@Kris57277]

That is exactly what i am planing to do

[@tubularap]

@@Kris57277 -- Me too. For the peace of mind a BMS offers, and combine that with testing (and learning) what happens inside, after making the pack.

[@JeffMoche]

I just deleted my comment, because I just noticed yours, and that's exactly what I'm planning to do as well. I'm closer to a novice though, so I'm glad my thinking was correct.

[@connectionlost1063]

You don’t need to be quite that stringent with li-ion cells as decent quality cells paired with a good quality bms that is spec’d correctly for your current draw requirements then the bms will way outlast the cells you plan on running it on. If you plan on building the slightly more juicy lithium polymer based batteries then this is a good safety net idea

[@Adultscapegoatchild]

Dude your just Awesome . Probably saved a couple hundred eye balls and probably lives too. Amen

[@D60Ebby]

Great video. How about one on how you set up your work bench & work area.

[@noahriding5780]

People say Lithium batteries don't do well in cold temperatures. I wanted to ask if this also will make it harder for them to charge up in cold weather since they already don't do as well in it? Thanks.

[@stvcolwill]

Really good video. I appreciate your not going BMS only route!!! I personally went to the dark side (not extreme though). I have connectors that I've installed on my mega battery (ebike DIY battery 14s10p) that enable me to split my battery in two for charging... and I use an iCharger Duo.... so that I CAN keep an EYE on all segments while charging. I do appreciate your advice on installing segment alarms, they're pretty cheap and I honestly hadn't thought of that.... though I tend to hang out in the top 2/3rds of my battery's range (can't deal with the lack of power in the lower range). The biggest problem that I have with almost all BMSs is that I can't tell whether they're working ...most of them are just boards without any interfaces. I'm the kind of guy that would really like to see the progress or error codes or status..... and yes, I've now paid through the nose with the iCharger Duo. I do like my set up. the iCharger is small enough to pop into a small backpack with my iPad pro or MacBook. I keep a 750W power supply at home and one at work as well so I don't have to lug those around as well. I should send you a pic of my finished battery - been using it for a good while now. Thanks for all your help previously and keep the awesome videos coming!!

[@sebastiandeleon126]

That was a very clear and tidy explanation, thanks!

[@michaelepps6700]

You answered my question. That's what I was looking for. Thank you...

[@nettoyageadriance]

It's amazing how big the world of batteries and bms is. Thank for opening that up to us!!

[@JH-pf6cd]

Great vids

[@asbjrniden3621]

I have resorted to doing both, as I was paranoid I connected both bms and balance wires on same battery and have compared the charging voltages of both. Happy to say that the bms has done a great job, only straying one hundredth of a volt at times after charging, but I like the convenience of having the balance wires as well for easy checking what is going on.

[@bryancunningham1095]

I think the added balance wires in addition to the BMS is a great idea, wouldn't be much added cost but would give us a look into the sealed battery to periodically check.

[@SoftBreadSoft]

Essentially yes. There are primitive solutions like voltage sense/alarm gates with bypass switches for each battery, the dead batteries will stop outputting and switch the circuit to charged batteries. Though this is not great in a series circuit where you need a constant voltage.

[@SoftBreadSoft]

(And the inverse for your charging circuit, would be a balance charge circuit.)

[@ericn3501]

I use a BMS on all my battery packs. Thanks for the informative video. Electric stuff is fun. Now I want to make an electric car.

[@tubularap]

True, electricity is fun, and tinkering with it leads (almost inevitably) to the final goal; build your own car.

[@H20RIDER]

I’m about to rebuild a couple of Segway Lithium Batteries. They take 18650 3.2v 6000mAh cells. (Segways batteries have BMSs). I see some 18650 3.2v BUT 10000mAh.cells on the market! Would these be safe? Would the BMS “understand” them? I suspect that if they are appropriate, the travel range would greatly increase. Suggestions?

[@Taiwan_Prospers_with_China]

Another important feature of any good BMS is current overdraw protection which is equally important in maintaining the health of your battery pack.

[@renantecainta3043]

Great video! I will always choose to use a BMS for my 18650 battery pack. It helps protect the battery in overcharge and over-discharge. It helps to prevent damage and fire. :-)

[@stackcruiser7]

I got a full laugh out of the BMS joke. I appreciate the humor.

[@christopherowens2635]

I’m rookie at BMS. Quick question...Are bms only to safely charge and balance the batteries during charging time? As far as using or discharging the batteries, does the bms play a role? Ultimately, can I use my batteries on a ebike without bms and charge the batteries later on a nitecore portable charger?

[@kendrickapps674]

after using off the shelf cheap BMS's I decided to design my own with an arduino at its heart and where possible off the shelf components and premade arduino modules. this minimises smd soldering. It is not an all singing all dancing device it does just what I think it needs to do, there are other devices that can handle the missing functions IMO. would you like to have one to look at when it is completed. kendrick

[@Joseph.Carrion]

Can I get a reply on this question please? I purchased an ebike, and the battery pack is 20s 15p 72v 150a. The BMS that the manufacture is providing, doesnt have bluetooth connectivity. I would like to find a BMS that supports my battery pack and also support smart connectivity. There's no real way to identify whether the BMS has failed or not. Can you help?

[@adityashukla775]

Share some knowledge about MPPT charger in solar panel.

[@Xtrafix2015]

Great tips I wonder if you think soft batteries are better then 18650’S

[@controlyourfuture5477]

Just use LifePO4 , might be 15% heavier but they don't catch on fire and stay within balance on their own. You get more cycles out of them as well.

[@electronica7385]

thanks from Spain

[@dznuttzonyachin7499]

Are we to the point where integrated gps modules are included on BMS system ?

[@NexiTech]

I use smart BMS in my both E-bikes. It cost just little bit over the regular price BMS but they comes with USB and Bluetooth connectivity. I connect it over Bluetooth to my smartphone. Over the app you can set and monitor in real time so many things including speed that you travel, temp of battery and BMS, Voltage or see all individual cell pack, you can disable/Lock BMS like E-lock. You can see remaining range... It has so much useful info and you can set parametars over app and program it however you like. You can set discharge,charge limit, phase amps, capacity of battery, Discharging low limit, charging high limit and you can set bettery balance to charging only or all the time and so much more. Smart BMS are the best thing ever.

[@celeb18]

Where did you buy from?

[@NexiTech]

Dariusz Czarkowski Aliexpress. Just search for smart BMS.

[@bobravenscraft5376]

A bms that can balance by Bluetooth has my attention cool

[@theman-jo4rr]

for a 12s4p battery, could you have a single 12s bms wire for each P or is it more important to have a bms for each P?

[@RND_ADV_X]

Can I use a 3s balancer to control 2 batteries in series? The only BMS that had stats I was looking for has 3s, but I have a 2s system. If I leave one of the balance wires unplugged, will that interfere with the BMS?

[@officialhonorupdates]

Do I need bms for single cell lipo 3.7v 2600 mah

[@lesliegetz1848]

Great content, thanks Mica.

[@briandhoward6137]

Great information as always. I can't seem to find information on how to do duel batteries, I'd like to be able to run on one battery at a time. The idea is to flip a switch to change batteries on the fly with out stopping. Can you make a video on how to do this ??

[@franciscosanchez9406]

You got three lipo battery and they got a protection board and trying to put them in parallel is it better leave them only or take those protection boards out and put one board for all three battery?

[@jwb3034]

Great Video. I have one BMS which cut off my battery power supply after 5v being used and still have 95% of power on each of 20 battery cells. What can I do with the BMS board? Replace or repair it?

[@adolphusmartin3216]

Hi MicahI am from the UK. I would like you to make a video on how to make a 72v battery, triangle and a rectangle.I have purchased three of your books to support the channel. Your video's are Great.Thanks.Adolphus Martin.

[@janmessek1826]

What you need to mention is that the bms tends to drain the battery all the time and if not charged every two to four weeks it can discharge the battery so low that it may not charge and even damage the cells.

[@vtorsi610]

Parasitic Drain varies tremendously by brand ...

[@rkpine2485]

I watched a number of videos about building a lithium battery. I understand the wiring of the battery and the need for a BMS, and watched the wiring of the BMS but I have not heard anyone discuss how to choose the appropriate BMS. 4s 36v current draw ? what criteria in numbers do I use? Please help!

[@vtorsi610]

BMS for a Battery is selected by #1) Number of Cells in SERIES, #2) Cell Chemistry, #3) Max Amps. If the batteries are then connected in SERIES, then the Total Voltage must be supported, too.

[@HeroCP7]

Is there a BMS for parallel cell pack? I don't need a higher voltage from a series pack, rather I want to prioritize the mAh. So far All BMS I've seen has more than 2 battery cell.

[@vtorsi610]

Are you looking for a Over-Volt / Under-Volt BMS on EACH Cell in a parallel pack? They certainly do make a 1-Cell 1S BMS board! Example = www.ebay.com/itm/383383797004 Select the # of MOSFET''s for your amperage

[@arizguimba8995]

I like to have a copy of the ultimate diy ebike guide and diy lithium batteries.. thanks in advance..

[@tr4nsporter]

Hi sir. If i want to build pattery pack with bms. Do i need to buy cells that is "protected" or not protected? Thanks

[@valdislivdans9740]

nice man!

[@BrunoBostick]

I have lear a lot with your videos, keep doing the good job! (y)

[@murdelabop]

In my opinion, whether to use a BMS or not is something called a "plumber's question". There is no right or wrong answer, just decisions and the consequences of those decisions.

[@dmpme951]

yes, one mistake could lead to flood in the house .. other will lead to burning fire btwn your legs.

[@earlbrown525]

Great explanation! While I was on the wall for a long time, I finally decided balanced charging and voltage monitoring was for me. I like knowing what I have. A BMS does have it's place however.

[@vincentrobinette1507]

that's an absolute necessity for lithium Ion cells, both for longevity, and safety! I'm sure you remember the "Hoverboard horror". That was due to many cells in a series, with no voltage balancing.

[@cheekonv]

@@vincentrobinette1507 Im Ditching my BMS after years of Lipo boats iv never had cell fail and i have BMS not running 20s through

[@vincentrobinette1507]

@@cheekonv Check your cell voltage at full charge after 20 cycles, before you finalize that decision. If you're charging to 90% or less, and making sure not to discharge below 30%, you can get away with that for quite a while. The only thing voltage balancing does, is compensate for differences in self discharge rate from cell to cell. During discharge and bulk charging, I prefer NOT to use voltage balancing. I want to keep the loading coulombic. Make sure each cell gets exactly the same number of Amp Hours, weather coming or going. The only time I like balancing, is during the top absorption charge. Using voltage balancing while the battery is loaded, can do more harm than good, if there's any difference in internal resistance, and differences in capacity from cell to cell. No two cells are exactly alike. I have found that a perfectly top balanced battery will show differences in voltage, when the current is high. The balancer has a tendency to favor cells with higher DC resistance, meaning those cells don't pay out as many amp hours as other cells. That actually UN balances the battery! as soon as the load is removed, they recover to a more equal voltage, once the load is removed. If you discharge a perfectly balanced battery, you will find differences in open terminal voltage among the cells, due to slight differences in capacity. Once charged, they will, again, come back to nearly equal voltages. After a period of time, the cells will fall out of equalization, due to self discharge rates. It's more of a time, than a cycle thing. Once that happens, the only "cure" is top voltage balance, then, you're OK again for a while. As the cells age, this will have to be done more often. Top voltage balancing is "good medicine" for batteries, but like any medicine, you need to watch the dosage.

[@felixjamesonevans6428]

what is the big battery you have in frame (not the turnigy)?

[@XfireKeenmike]

8:30 "get off of your bike and walk"? What do you mean

[@standeyoe7468]

does this mean that if i purchase a BMS from vruzend that it will be one of the best ?thanks for your good work .

[@1112223333111]

I have a 48v 26ah pack and it had imbalace section. I got it charging then the green light come on but with I unplug the charger it falls to 38V. I plug the charger back in it shoots to 54 and stays green. I tore the battery pack open and unplugged the bms and jumper the charger straight to the battery bypassing the bms and still same result. does the 18650 have a fuse in it? it floats 54v but no current. thanks!

[@thelonee-rider2301]

Hi Micah finally found the Comment section. I want to build a 70v60a Ebattery. I'm having trouble estimating how many batteries I'll need. HELP!!! Also from your videos I've learned about the 12v increments. Any idea/tips on the shape will help a lot Thanks Signed A senior/veteran eager Beaver

[@illusionistsam]

You will have to make 20s 30p that makes 600cells

[@illusionistsam]

If you are aiming for 72v nominal

[@bryantimms1469]

Question. If i were wanting to run 2 72v batteries in parallel when each battery has their own bms built in, is that possible? I know that you need to be carful of the voltage on both battery meaning they ideally need to be identical voltage. Im talking about 2 identical 72v batteries. Charging them separate. Just if i were to run them parallel would there be issues because there is 2 bms’s in the system? Thanks. This is a project for a electric full sized motocross bike!

[@creativecityis]

Any easy way to test capacity of 10 or 13 cell batteries. (Capacity of each individual cell Bank)

[@ideafromkurdistan5257]

if use simple charger for li ion i think not bad ?

[@voiceofinsight5811]

I found the battery in the link below on ebay, they are Li-ion batteries, is it a good idea to build a bigger battery from them following your method above? If it's not a good idea, why not, @t

[@haulngrassracing]

I’ve used BMS’s (and even bought a few off of your website) but I’ve found that no matter how much I spend they usually fail sooner than later. Now I have a battery voltage gauge and a cheap volt buzzer that is set to the lowest I want it to go and shows me the voltage of each group and how far they differ from each other. Plus a balance charger. Great video Micah!

[@EBikeBuilder_]

agreed , the BMS always seems to fail

[@azertaieb442]

What do you thenk if i use a car alternator 12v 30A as a brushless motor with a 48v20ahm ? And did a bms brock ?

[@bradybrown510]

Good info. Thanks

[@shaunhicks85]

You mentioned the dual BMS you put on a kids you car. I'm curious how you wired that?

[@welcometomychannelswelcome7261]

See, some people don't understand about BMS and without it BMS can use on the used cells. If your batteries are new, you will be ok. And make sure you have Good connectors. Also right changer..

[@thanapatrachartburut513]

Why lead-asic don't need bms?

[@dbmiller5881]

I have never found a balance charger (hobby charger) that would do more than 6S. So when I want (as per your example) a 36 volt or 10S battery, I have to make two separate 5S packs, that I can balance charge individually. Is there something I'm missing? (like a source of bigger chargers?) Personally, I like doing my own balance charging, but it would sure be nice to plug in a single charger for my 72 volt pack!

[@vincentrobinette1507]

If you could interleaf voltage dividers, you can put as many cells in series as you want. Even electric vehicles, running well over 300 volts! A divider can be as simple as two identical resistors hooked up the positive input of an OP AMP, then connect the output to the inverse in of the op amp. you connect the resistors, and the op amp power pins to the outer terminals of two series cells, connecting the output to the interlink between the two cells. If you have three, take another divider, and connect one terminal to the middle of the first two cells, the other to the terminal of the third cell, and the center tap to the junction between the second and third cell. I wish I could attach a schematic, but I don't know how to do that on a reply. You will need exactly 1 fewer dividers than the number of cells in the battery. It could be good if you use relays, so you can connect them near the top of the charge, then disconnect them when the battery is in use.

[@alcusminix5527]

ICharger makes 8S and 10S balance chargers. They are not cheap as they can handle high amperage for large packs. Search for vendor Progressive RC. Been using these for years and vendor is very good.

[@cheekonv]

@@alcusminix5527 Yeah im Ditching my BMS and doing it like this. My controller shows me through bluetooth what voltage app is and it will cut it off it want to, i u much rather do this.

[@vtorsi610]

@@cheekonv Individual CELL Voltage ?

[@cheekonv]

@@vtorsi610 yes well cell in parallel at lest i can see which group.. ANT BMS with VBMS app

[@o1ecypher]

awesome i love this channel

[@duzzd]

Can you please explain us how to make battery with two BMS?

[@EbikeSchool]

You basically wire them in parallel but that'd be a great video, I'll try to do it.

[@duzzd]

@@EbikeSchool Thank you, looking forward for that video 😊

[@R.B.forMER_S.]

@@EbikeSchool yes please make that video on 2 BMS.

[@dmiksa75]

@@EbikeSchool yes would love to see two in parallel

[@ptmoy1]

@@EbikeSchool Good idea about another video. I would like to know as well.

[@bazonpixel]

Hy. Can I connect 15ah BMS for a 25ah battery? Will the battery burn the BMS? Thanks!

[@utubeape]

there is no such thing as a 15 ah BMS. 15 A is the maximum power output. 25 ah is the capacity of the battery.

[@Loyalg1]

Can you connect 2 36v 10ah together on a 36v bike staying at 36v to get better range?

[@TonytheCarEnthusiast]

Loyal Gaskin yes sir fairly easy

[@TonytheCarEnthusiast]

connect them in paralel and you should be find !

[@louisgabriels6333]

Thanks , this is a good video to understanding .💞

[@agmendoza2830]

I built my first battery by following the instructions from your videos and used all of your components . I really like the idea of having a BMS monitor the batteries for me. Keep up the good work.

[@anasmoustafa7286]

Was it easy to use the BMS ? kindly advise which manual or video did you use to handle it ..

[@agmendoza2830]

@anasmoustafa7286 same components he used in the video I used and I just watched another video to install it

[@trewmika1869]

I have made loads of lithium batteries, and I always include balance port, even if I have good balancing BMS. It makes it easy to check if anything goes wrong. Sometimes the balancing is not included in the BMS, so I have to balance charge it. Anyway, if balancing is not included, the BMS should still be able to cut the battery off once one cell starts to overcharge.

[@phantom2226]

Did anyone know where to buy the BMS for 19v Dewalt LI-ION? I used 5 of 19850 3.6v (18v). Thank you

[@davidrogers5343]

and a controller is an off and on switch

[@SolidGoldWatch]

I use the 3rd option , no bms , also no balance charging . I use "high ceiling" method , 48v charger can charge up to 55v , i use 17s Lifepo4(55V) instead of the norm 16s(52V) to make sure my battery never reach full charge , so that the fast charging cell never reach 3.65V which is the limit for Lifepo4 battery

[@E85_STI]

I have a bms on a 12v 3s2p pack and I have a balanced 3S wire hooked up because my imax b6 mini doesn’t allow me to charge without the balance plug. Here’s my issue I bought brand new Samsung 25r batteries so everything was charged properly but my B- B+ tabs read lower voltage that the actual pack reads. The pack reads 12.65v and the output plug reads 11.55v so I’m not sure why that is but I do have a few voltage alarms and one with a lcd screen but I’m not sure if the cells will discharge evenly so I left the bms on but I just don’t get why through the bms it reads lower voltage.

[@bawsedogg3675]

Love the you keep a fresh black tee 🤷‍♂️😅😅

[@mahmudhasan2120]

Can u suggest me good quality bms please

[@floritobentillo6941]

If use a TP4056-Protect charging module,do I still need a BMS? thanks

[@tubularap]

I am just learning myself, so take my advice with caution: The TP4056 is for charging the seperate cells, before they're being put in a pack. The BMS is inside the pack, meant to work after the pack is finished. So the answer is Yes, you need both, cause they have complimentairy functions, not overlapping.

[@KraXed112]

This is all good info, I’m tempted to make a battery for my Onewheel

[@ebikesolutions500]

Can you do a topic on amps and bms like I'm using 14 cells in series and 10 cells in parralel 140cells in total half 70 2200mah and 70 2000mah 18650 new laptop cells so 50 amps continuous 5 a per cell can I use a 52v 45 a bms on this pack ?

[@franzereyes2448]

I got 4 x 18v 25Ah battery pack with BMS each pack. Can i use a 72v charger and charge them in series?

[@franzereyes2448]

I have been reading alot of forum online some are saying it is safe, some are saying that it will overload the BMS and some are saying that just add diodes and it will work fine. My problem is, i cannot make a 1 x 72v battery pack because it will not fit on my scooter - the plan is to connect 4x18v pack (with BMS Each) and connect them in series to get 72V. and take advantage or charging the pack aswell using a 72v charger.

[@rachidbaaira9869]

Hi, plz I have a question : can I run a Xiaomi scooter (250 watt) with 36v hoverboard battery?? ( I make path just a 2km distance in day) , plz someone answer me. tnx

[@andrewvaudin8687]

have you ever considered LG M50 5000mAh/10A Rechargeable Flat Top 21700 Batteries?

[@martinsbardulis]

What battery type is safer? (Li-po or Li-ion)

[@okcrc]

They are the same. They are just packaged differently. Most would say a round cell in a metal case (aka li-ion) is safer than a pouch cell (aka li-po) only because it's more difficult to puncture. They are almost equally dangerous when charging but a pouch cell will show early visible signs (swelling) of failure before catching fire. Both are safe if handled properly and both are potential fire bombs if handled recklessly.

[@martinsbardulis]

okcrc tnx

[@bp5082]

I think the best practical solution to charging cells is to allow them to be removed easily and charged individually like with an xtar vc4. You will know status in real time. Any pack I have bought had bad cells that affected the charging of the other cells. Quality of affordable bms is really bad and balance chargers the same. You need to have the ability to charge each cell and see its status. The diy kits like verzund are very good. Anyone who reads this know that u will save a lot of money on your build and long run as well. These batteries are dangerous btw. I don't think them rubbing against each other in a shrink wrap is very safe! When an 18650 shorts it doesn't spark, it glows red like a coal in a stove and ignites the other cells and from experience I can tell you some will take of like flaming arrows. Always check voltage of cells when they arrive!

[@keithballard4621]

I put my cells in a pvc pipe, screw on the threaded end caps and extract them with a telescopic magnet out one end. They are always charged and monitored individually with multiple chargers. There are several ways to mount the straight pipes on any bike. Can even make them look fancy. I’ve done six so far.

[@anthonyvolkman2338]

Ballance charging is good (I've used both) but you have no over current protection when discharging your battery, this can be dangerous at times. So....... I cheat, if I balance charge I will build my own over current and UVLO (Under Voltage Lock Out) to cut the power in low voltage situations and over current situations, in this way I can have over current protection for instead of a few hundred about like most high power BMS boards I can actually have thousands of amps or whatever I wish.

[@Kris57277]

I bought the cheapest 16s bms i could find for $15 but its already in my ebike and i haven't tested it yet should i be woried? (Btw its a 2 wire bms were charging and discharging happen with the same plug rated for 45 amp cont. From aliexpress)

[@LawAbidingCitizen117]

Throw it away and DON'T get the cheapest one next time.

[@mnjba]

Place tell me which transistor BMS board to buy, rather than saying cheap one or high prised one

[@michaelaugust7233]

All of your videos are not only spot-on informative, but awesomly entertaining! Thanks, great help.

[@ruelgamez5924]

i have a question, i have a diy scooter trikke i am using three 48v 350 motor my batery is 48v 13s4p 10amps or close to 10amps with BMS discharge rate 35amps now if i accelerate quicke enough or most of the time while riding it shuts off, i will turn of the switch to off the back to ON and it will work again, do i need to replace the BMS on a higher discharge rate to eliminate the problem? please help thank you.

[@noobz5056]

Two options: 1). You can increase the number of series connection by 1 or 2 row. Modify the charger to allow full charging to make full use of the storage. 2). Remove the BMS so that it won't cut off on you due to voltage sag from the battery cells. Another problem is most batteries out there can't handle high current charging and they degrade fast so their lifespan is shortened. They are also nearly worthless in the cold freezing weather as the charge gets lost very quickly. Better off to build a battery pack with real good high-performance cells without the BMS for best performance and long range.