15S4P Li-Ion (NCR18650BD 3150mAh each)
AFE = BQ76940
Cell Balance Threshold 4000 mV
Cell Balance Window 100 mV
Cell Balance Min 40 mV
Cell Balance Interval 20 s
Balancing current ~325-400mA from 4V to 4.2V
That's actually the first time one of our pack gets into balancing and I have the feeling there is something wrong.
Balancing had been going on for roughly 45 minutes while charging (near 100%). Soon after I removed the battery from the charger, the balancing stopped.
A few minutes after, I put back the battery to charge. Balancing did not start and valid charge termination occurred in less than 10 minutes.
It turns out that the small unbalance I had noticed on one cell was reduced well under the unbalance threshold. So, something worked, but it looks like I had to break the loop.
Could the balancing current be too high or the thresholds badly set?
What are your thoughts?
Regards,
Frederic
