We are using the BQ3050 in a 3S2P configuration. The cells have a capacity of 4400mAh each. We are experiencing a problem with the remaining capacity which is not getting updated on several packs.
All packs are calibrated and get a default configuration file. (see attached)
Battery #22 is behaving correctly. We draw approx. 300mA from the pack and the remaining capacity drops by 1 about every 10s. Battery #15 is not reducing the remaining capacity under the same condition. We observed that the remaing capacity dropped to 6% after the battery was almost depleted. Then suddenly dropped to 0%. During charging the remaining capacity increased until reaching 100%. On the next discharge it still didn't count down. I used manufacturer access and send the command LTPF enable. The remaining capacity got updated immediately, as if the device was counting the charge value in the background, but did not update the remaining capacity field. Sending a reset command via manufacturer access did not change the behavior. The device kept counting the charge.
We then disconnected the BQ3050 from the batteries and reinserted it. The device showed the same remaining capacity value as before and again did not count the discharge. Sending the reset command had no impact on the behavior. Sending again the LTPF enable command solved the problem and the device updated the remaining capacity. We then updated the firmware of the BQ3050 using the default firmware file from the TI website. After reprogramming the data flash the device seems to be ok and we cannot get it back into the condition of not counting the charge.
We checked the bq3050 device markings of battery #15 and #22 and they are from the same lot.
It is interesting that the LTPF enable command is necessary. The lifetime data is not updated either, until the command is sent to the device. The LTPF bit is set in the CfgC. IMHO the command should not be necessary.
Best Regards,
Uli