Dear all,
I am student of an Higher Technical Collage in Austria. I develop in during my diploma project a mobile power station for Notebooks and Smarphones. For this device i use the BMS BQ77910A.
I have designed a own PCB Board for the BQ77910A. The board works perfectly if I take the resistor simulator. It turns off when the programmed overcurrent occurs. When I connect 10 lithium ion cells, the FETs are not switched correctly. I have about 2 volts voltage drop across the FET. The Cells has not the same Voltage. They are loaded differently by approximately 0.2 volts.
Has anybody an idea?
Thanks for your help!
Best regards
Tobias