I have 4x10 (36V nominal, 9Ah) lion battery.It has wierd 5 pin charge connector. Original charger does not send any voltage, when battery is not connected.
The discharge connector has 4 pins, of which 3 are connected. Voltage goes to both, but the 3rd discharge pin is not connected to charge connector.
I used Chinese charger hooked to voltage pins i found using multimeter.
BMS did not allow this, as the chargers standby
is 42.4V ( measured. 42V on sticker), when the original charger reads 41.8V on sticker. (not measeured)
I solved this, (and added partial charge functionality) by adding diode bridge made from 0.7V treshold diodes, creating 1.5V drop ... and the bridge turned hot.
The battery charged with 1.31A current, and reached until 40.9V at which point the charging stopped. ( Like I wanted to.)
If I press charge indicator button, the leds in the side of battery shows low charge, despite multimeter shows 40.9V.
How can this be ?
Are additional problems being expected, like BMS shutting down despite battery having "unoffical" charge(DID NOT), or balancer newer running?
The bike is Giant twist freedom 2 GTS, and dates back to around 2015. It has 250W yamaha mid engine.
