My perfect BMS would simply waste the energy passively, instead of trying to move it around, and it would be capable of at least 1 amp discharge rate per channel. This way, I might actually be able to charge at 15 amps, and have a BMS that can balance the modules as quickly as it charges. Then all I would need is telemetry.
Batteries, imho, are getting too big for active management.
That’s actually what most BMSes (including FlexiBMS) do.
How did you come to that conclusion? You realize that the charge current is the same for all p-groups so even if you had 15S, each p-group would still charge at 15A, so even if you were able to leak 1A per channel that’s still nowhere near “as quickly as it charges”.
It all depends on how many cells you have in parallel. I’m not sure by what you mean that the charge current is the same for all cells- yes of course it is, but the more cells you have, the less current each one gets. The more cells you have, the longer it takes to charge a battery at any given amperage.
P groups are looked as one cell
Each p group connected in series gets the same current
So for example if you have a 12s4p and charge it at 5a all 12 cells/p group connected is getting 5A
Right. I actually meant “p-group” where I said “cell”. Let me edit my post.
Let me put it like this- wherein lies the limitation with regard to quickly balancing large packs of 100 cells or more.
Quick balancing isn’t really need though is it?
This is esk8. We have zero patience.
Imho, you need balancing that works faster than your charging. Otherwise, the BMS will stop charging, and balance instead. Right? Because if one module is higher than all the others, it has to bring it into equilibrium before the rest of the modules are fully charged. Otherwise it could explode.
So you need balancing resistors bigger than your charger 10A 15A 20A with a huge heat sink to try to keep them cool this is just not practical
Balance resisters are working up to the max voltage of a cell not the charger voltage you can’t just devide the amps by noumber of S.
If your balancing packs that need this then it’s a very unhealthy pack stop useing it
If you need 1 A balancing there is something seriously wrong with your pack
Once balanced it should stay that way, and if it drift, it should be significant only after a bunch of cycles
Recieved mine units, cant wait to install them to my board 
I say this all the time but I fly race quads and I esk8 both have dangerous batteries and need to be managed correctly otherwise you will end up with fires.
This ranges from 1s1p all the way to 12s5p - both LiIon and LiPo which charge in the same way. Charge -> balance. This is how all of your tech works and there is nothing wrong with it. Nobody needs or wants stupidly large bms modules with massive balanace resistors and heat sinks when well made and managed batteries suffer little to no drift to begin with. Not to mention, you really shouldn’t charge higher than 1c and if you charge slower it’s actually better for your cells. Oh and on top of that - If you have an unbalanced p group, the BMS will cut power to charging if it exceeds the maximum voltage of the cells anyway. This is per P group regardless of what the total voltage of the battery is.
One thing that I would actually love though is a small/compact pcb that could isolate and split my 12s batteries into 2 or 3x(in 18s) 6s batteries for charging with my 6s hobby chargers. Or even flip an 18s battery into one large 6s for simple charging. It does make me a little concerned doing this when you have a heap of p groups with varying voltages but I parallel charge all the time and it’s quick and easy. I think a large problem we have in this community is a lack of “well made and affordable” chargers.
I’ve been using both 10S and 12S yzpower 4A chargers for my packs and never had any problems. You can buy one under $30 shipped from AliExpress.
The difference is you can get a pretty great hobby charger for the same price with a lot more features.
Why do you need a charger? you need a cc cv power supply
Show me a 12s hobby charger that’s better and 4-6 amps
People on here want everything on the extreme side and 4-6A yzpower offers doesn’t cut it i guess
11.2A
Why do you want a Lipo balance charger with a bms?
