I've got some battery packs using the BQ2060A that have been in the field for quite some time. They've undergone short usage and recharge cycles. Every time they're used, FCC seems to drop by 512mAh.
Now that the units have been in the field for some time, FCC is around 6000 on some instead of 8800. The units have been through ~ 250 cycles. If I run them "flat", they can actually deliver more than they say, so I know the 6000mAh is lower than it should be.
I've tried doing a reset of the pack and setting the relearn flag. The moment I set relearn, FCC and Life Remaining both go to 0, so it's obviously working.
I then try to run a discharge/charge cycle to restore the FCC to a reasonable value, but it ends up only around 6000 again, give or take.
I have two questions that don't seem to be answered by the documentation...
- what's the proper procedure for a "relearn" cycle? Set the relearn flag, yes, but when? With the battery at full charge? Zero? And then what comes next, run a charge or discharge?
- is there any other procedure to reinitialize FCC to the designed value so that I can do a proper capacity test? Or even an arbitrary value that I choose after testing how much usable life it gives...
Thanks...