how would you test them ?
but for 2$ that’s a steal for sure(compared to the xiaoxiang at 75$ without a BLE)
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prolly with a 10S pack and see if it charges normally
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that’s what I thought 
if it works well that style of bms’s would be great for us since it’s low profile and can run it bypassed.
just tell me I don’t actually need one cause I know i’d get one rn
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I’ve got a ton of those from my salvaging days, and the other all pcb style too, theyre fine if you use a 2A max charger, also they burn out easy if having to balance a long time
I had some crazy ideas …
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ok so don’t hook it up to one of my specialty horribly unbalanced packs? lmao I see where the $2 price came from, can’t sell that to someone in a board haha.
Maybe charge and ride packs.
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Now thats a deal. I seriously might pick up a few.
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It says in the decription to test if the bms alows over charge.
Volt check on the p groups see if thay charge past 4.25v
Volt check on overall voltage see if it charges past 42v
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we don’t, it’s big sad 
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With these dumb BMS, could you just hook up a single group that’s above 4.25 and see if it drains it?
Or does it have to be connected to the charger to balance?
I’d say it probably needs to be on a charger. So the best testing method would be to have ten single cell holders, with nine <4v cells and one >4v cell, and swap them around in the holders to make sure each balancing channel works.
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Shameless plug
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Wow that’s a work of art
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I’m going through and testing a shipment of Tesla 3 21700s for new packs. Half are 3.69v and half are 3.68v. Should I just put each one in their own p-groups or should I charge the 3.68v ones to a common 3.69v?
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I personally think thats fine. I think a general rule of thumb being used around here is +/- .05v
But you can if you want, or you can build the pack and do some charge cycles to get them to balance
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This is what i would do.
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I personally wouldn’t even bother. The difference is so small as not to matter.
But the easiest way to deal with it if you are really concerned would be the evenly split the different voltages per p group.
So if you were building 4ps, you would have 2 x 3.68 and 2 x 3.69 per p group.
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i agree… whatever you used to extrapolate battery voltage is probably not accurate to .01 volt anyway.
mix the voltages as best you can and then check the p-group voltage once assembled. likely they will be butt-ass close
if not balance your p-groups manually before you put the battery into service
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