Hi, I have implemented the circuit provided in the SLUA447 application note for the BQ2954 and modified it to control the charging of 18 40Ah Li-ion cells. The parameters are: Vin=114V, Imax=7.8A, Freq=168kHz. R9, R10 are 1.02M and 33.2K respectivly. R13 is 0.033R. TS is set to half VCC-BAT-.
My problem is that when the charger is powered on with a battery pack attached it drops through S01 and S02 within 2 seconds and continues with S03a. At this stage the charge current will rise to Imax and stabalise for about 2 seconds with LED1 on. Then the charger will shut of and CHG will go low.
The only exit from this state is to power off the charger.
Has anyone any pointers to this problem?
