Hello,
We have a battery pack design around the bq20z45. The same PCB is used with multiple cell types and configurations. Works perfectly on the bench with lab supplies and loads. Our customer designed the chargers, and are trying to make the battery pack worth with multiple revisions new and old of chargers.
There is a microprocessor integrated on the battery board that controls some battery functions. And the smart charger handles precharge by pulse-charging the battery until it recovers from undervoltage. What we observe, however, is that the discharge FET is turning on with the pulse charger even when the CUV fault persists. In addition, sometimes the offset calibration drifts. It is not stable, and affects the ability of the customer to force the packs into shutdown.
I would prefer to take detailed discussion offline by email. We can provide schematics and additional information on the chargers and any other information necessary to help us figure out what might be happening in the packs.
Thanks,
joe p.
