We've been using the host controlled balancing on the BQ76952 and are testing turning on balancing on a single cell. We see the following observation: Over a period of 10-15 seconds, balancing is on or upto 5-6 seconds at a time and then turns off for 1-2 seconds randomly before turning ON again. We're unable to explain this random turning OFF.
Possibilities we've ruled out:
- According to Cell Balancing With BQ769x2 Battery Monitors (Rev. A) (ti.com), the device modifies the timing on the CUV check on an actively balanced cell and the COV checks on adjacent cells, disabling balancing briefly every 1-sec to allow these checks to occur. If a CUV or COV alert is detected at the 1-sec check, balancing is immediately disabled.
- We've monitored the COV and CUV safety status registers and can confirm none of these conditions is tuning OFF balancing. Also the cell voltages never cross either threshold.
- According to Cell Balancing With BQ769x2 Battery Monitors (Rev. A) (ti.com), The device includes an internal die temperature check, to disable balancing if the die temperature exceeds a programmable threshold.
- We've monitored the die temperature by polling it every 200 ms, and it is never seen crossing the default threshold (70 degrees Celsius).
Is there another factor that could cause this?
