BQ40Z50-R1: Balancing LiFePO4 with bq40z50-R1

Venugopal S

Part Number: BQ40Z50-R1
Other Parts Discussed in Thread: BQ24650

I am using bq24650 charger along with bq40z50-R1 for charging and management of 3 series cell LiFePO4 pack. Towards the end of charging, one cell voltage shoots up due to imbalances in SOC and then triggers Cell Over voltage protection. All the balancing arrangements I have seen and tried, takes hours to balance the cells, whereas this overshoot happens in seconds or minutes. Is there any way to tackle this issue ?

over 8 years ago

0 Onyx Ahiakwo over 8 years ago

TI__Guru* 76230 points

Venugopal,

This seems to be a problem with your cell. Have you tried a different pack and still experience this problem?

thanks
Onyx

0 Venugopal S over 8 years ago in reply to Onyx Ahiakwo

Intellectual 640 points

I tried with a 3Ah pack. same configuration - 3 cell series 1 parallel. Although this was much better than the previous 1.5Ah cells, still there was peaking of one cell voltage. What is even more interesting is, in each charge cycle, different cells are peaking - its not the same cell that is overshooting.

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BQ40Z50-R1: Balancing LiFePO4 with bq40z50-R1