rocwandrer
100 W
If one cell reaches 3.65v before the others, how much imbalance can there be when, after settling out for a few hours to dissipate the surface charge, all the cells read 3.38v?
In other words, can multiple LiFePo4 cells have less than 10 mV of resting voltage imbalance fully charged, and still really need to be balanced?
In a 6s pack with 8800 mah rated capacity, balancing took 1000 mah, even though the charger had just fully charged the pack without balancing the cells, and the resting voltages were all the same within my measurement accuracy. If I include the energy dissipated from the one higher SoC cell, that was really like only putting 800 mah into the pack at a maximum, but that is still a lot.
Is it possible I am wasting my time "balancing" when really all that is going on is the surface charge dissipation is so fast that a slight imbalance in the dissipation rate affects the detection of 3.65v, at low charge rates? I noticed it takes more total ah to balance the two packs in parallel than it does total between the two separately.
I might try to balance charge right after balance charging tomorrow, to test my hypothesis, but I'm still looking for input.
In other words, can multiple LiFePo4 cells have less than 10 mV of resting voltage imbalance fully charged, and still really need to be balanced?
In a 6s pack with 8800 mah rated capacity, balancing took 1000 mah, even though the charger had just fully charged the pack without balancing the cells, and the resting voltages were all the same within my measurement accuracy. If I include the energy dissipated from the one higher SoC cell, that was really like only putting 800 mah into the pack at a maximum, but that is still a lot.
Is it possible I am wasting my time "balancing" when really all that is going on is the surface charge dissipation is so fast that a slight imbalance in the dissipation rate affects the detection of 3.65v, at low charge rates? I noticed it takes more total ah to balance the two packs in parallel than it does total between the two separately.
I might try to balance charge right after balance charging tomorrow, to test my hypothesis, but I'm still looking for input.