Is lithitum ion BMS necessary?

I think BMS is must, but this guy think it’s okay without one. what’s your thought?

Watch his follow up video where he says good BMS are good…lol

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not necessary. might be recomended,

<40$ to protect your 150$ battery i think its worth it

In some cases is not. Depends on the chemistry of the cells. BionX has done some battery packs for ebikes using LiNiMnCoO2 cells. They are very stable and have self balancing properties. Sony konions have the same properties specially the V3 aka spinel vtc5 and vtc6 are so stable that actually don’t need bms as long as you have a proper method for lvc and hvc. I did myself some bmsless packs using those cells with a rc charger balance wire. everytime i checked they were like a mozart symphony, not a single note out of tone.

My friend Jim did a build for a Vectrix without bms using tesla cells. He checks every now and then with cell logs. So far they are in perfect balance. Check the build here


why are we not all using these LiNiMnCoO2 cells self balancing properties sounds amazing

Because they are quite expensive… you need proper hvc and lvc anyway.

lithium-iron cells (lifepo4), are impossible to blow up and can recover really well from over discharge or overcharging. they also have like 10 times the cycle life, but theyre bigger and heavier and more expensive. If you have the room for them though worth thinking about. they also are made by Headway with really nice screw connectors and some of them are very high discharge so you could use fewer cells and none in parallel.

with a good low voltage cut off on the esc, and proper care including charging somewhere that things wont go to hell…i think a bms is not worth the hassle. I’ve seen chargers that have blown up cells and many bms that are faulty. maybe more things get blown up relying on this stuff than human oversight.


a bms (or at least balanced charging via a hobby charger) is definitely necessary for charging lithium ion batteries (not every charge cycle, though). for discharging its not required. your (v)esc will usually prevent (or at least warn you of) over discharging.

there are many people who don’t use a bms or charging via a hobby charger. practically impossible to find a 12s charger.anyway. Coincidentally I just ran into a member here in the flesh and he was carrying around his lipo battery that had dropped to 2.4 volts because his bms didn’t work. I guess it wasn’t working all along and finally showed itself when he somehow realized. and I was telling him I think bms suck

Bms and lipo in the same sentence give me the creeps. I would never ever do that. I have been myself the bms for all my lipo packs. But that’s just my opinion… I see that bms on lipo is very popular here.

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