This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ76952: BQ76952

Part Number: BQ76952

Hello, 

We are trying to perform the host controlled cell balancing register configuration 

1. CB_SET_LVL = 2900 (cell voltage while testing is 3100).

2. All the protection is disable.

3. Thermistor is configured as the temperature input but not for the protection.

4. Below Parameter is configured for the cell balancing

MinCellTemp = 0
MaxCellTemp = 100
MaxInternalTemp = 70
CellBalanceMaxCells = 10
CellBalanceMinCellVCharge = 2000

CellBalanceMinDeltaCharge = 0
CellBalanceStopDeltaCharge = 0
CellBalanceMinCellVRelax, = 2000
CellBalanceMinDeltaRelax = 0
CellBalanceStopDeltaRelax = 0

Based on the ref manual understanding is created that the CB_ACTIVE_CELLS = 0x0000 -> cell  balancing is not enable | CB_ACTIVE_CELLS = 0x00n -> nth cell  balancing is  enable for set cell balance interval. (for this case it's 30sec as of now).  if   CB_ACTIVE_CELLS = 0x0001 it start the CB and the timer for the CB1 cell is start running same for the 0x0002. but, when we pass the value 0x0005 / 0x0006 cell balancing bit set active, total cell balancing active timer start increase as intended it's working but the timer for individual cell is not increasing instead of that some time it increase of CB1 or some time CB2 and on the board current is also flowing in same manner for CB1 nd CB2 respectivily but actually CB5 should start but it's not happening neither in the timer of CB5 nor on actual board.

Thanks & Regards

Nilkanth Vyas

  • Hi Nilkanth, 

    Please confirm if my understanding of your problem is correct. 

    Seems above the cell-balancing setting and delay is working as expected for cells < 5. So from CB0 till CB4 everything is good, but once you get to CB5 and above there's some mismatched on the timing, is this correct? 

    In addition, have you referred the to the Cell Balancing with BQ769x2 Battery Monitors (https://www.ti.com/lit/an/sluaa81a/sluaa81a.pdf) App Note. This shows specific examples of how to configure your hardware and firmware to perform cell balancing, and show the balancing curves. That might help debug the discrepancies you are seeing on your systems. 

    Regards, 

    Arelis G. Guerrero