Part Number: BQ20Z95
We have got returned batteries from customer complaining over batteries reporting empty after few cycles. Reading battery status using "bq Evaluation Software" we can see and measure that the battery capacity and cell voltages are fine, however even with 100% charged, Abs state of charge report 0 and RemainCharge Alarm (which we use in our device to activate safe power-down) is set.
Unlocking the battery and looking into DF shows every setup correct and identical to Golden Device. However - the updated Ra-table shows strange negative values for two of the four cells (4s3p config). for two celles - all gridpoints shows -32767 . All cells Qmax seems reasonable (6800 to 7000mAh) with Qmax-pack identical to the lowest cell.
We have tried charging - relaxing (day) decharging - relaxing again - see no update of the Ra values for any of the four cells at all !
What is wrong - what shall we do ?
We have produced this battery for almost 10 years - newer seen problems like this before
BR Helge Larsen