I have a 5S 18650 18v porter cable li-ion pack for my drill. I wanted to run this pack down to minimum voltage so I hooked up an incandescent 100 W bulb. The bulb lit dimly and I let it run overnight. I checked the voltage with my DMM and it showed 3.5 volts. I unsoldered all 5 cells and 4 were 0.2 volts with 1 at 3.2 volts.
- Should the BMS overdischarge function have not allowed each cell to not discharge below a certain voltage?
- Would this indicate a faulty BMS?