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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buy the one on the left it’s obviously more betterer
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oh yeah totally 
plus it’s not like they don’t ship to Canada 
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They have a bad habit of not taking the listings down once their stock runs out too. I think that one’s been out since June…
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yeah that’s a bad habit for sure
soo where should i buy batterys?
The first site that come in my mind was aliexpress official liitokala store with 18650 hg2 cells
All the other sites has shipping that is over 100USD to Hungary
Thanks for the answers.
You will receive legit fake cells 
I would have a look at nkon.nl their shipping isn’t too bad usually.
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