Tool/software:
Hi team,
My customer is testing BQ76952 and there is a cell balance issue need your explanation. Thanks
In customer system, they use two BQ76952 and 1st is used to monitor 1-10 cells and 2nd is used to monitor 11-20 cells. They do the cell balance test and open the call balance manually. They found the balance time between cell1-2 and other cells is different, please refer to below waveforms and confirm the reason.
- 1-2 cells balance time: 48ms, and the period is 448mA, so the duty cycle of balance time is 48/448=10.7%. The voltage waveform between balance resistance is below.
- Other cells (3-20) balance time: the duty cycle is about 90%, the voltage waveform between balance resistance is below.
- The test point is balance resistance of every cells as below red square show:
- Software set as below, the target is to get more higher balance efficiency.
- Before: Manually close cell balance before system read every cell voltage. Now: cancel this set and they don't close cell balance before system read every cell voltage and let BQ76952 process by itself.
- Set below register as 3
Best Regards,
Ryker
