DANGEROUS SITUATION? A LITTLE FREAKED OUT!! 48v ebike battery charged to 84 volts!!!! WTF
Ok this is so bizarre. I sell /service ebikes and this was the last of 10 identical bikes i unboxed and assembled this last one - it had sat in box maybe 3 years... plugged in charger and it was charging normally, voltage increasing. (oem charger that came with bike)
Came back to it after a few days (was super busy) and found the battery reading 78 volts.
Unplugged the charger and battery VOLTAGE STARTED CLIMBING AND KEPT CLIMBING UP TO 84 VOLTS!!!!
Yes I was absolutely ready with door open at this point to throw it out, half expecting bad things to happen.
nothing happened. battery is cold. no heat, no noise.
Tested Charger w/no load - 78 volts output!!! wtf? the others do not do this - should be 56v.
Im just posting this right after this happened. IM going out with a large resistor to discharge the battery but i have questions - hoping someone has seen this before.
Guessing this is due to faulty charger, not battery... will test further.
Is there any chance the cells are NOT damaged at this point?
Shouldn't the BMS have stopped the incoming high voltage? is that not a normal protection even on cheap bms?
(this is a cheaper chinese ebike but they do have high quality LG cells and the batteries are well constructed - i have torn one down before to know this).
Thoughts & warnings???