Full charge capacity depends on charge level

[lineslim]

Hi,
I got a new 13000 mAh battery for my eee pc from ebay. On full charge it shows 10600 mAh full charge capacity while after some discharging (about 75% left right now) this figure is 12100 mAh. I have cycled the battery from 100% down to 20-30% about 5 times. Why is the full charge capacity different at different charge levels? Which figure is correct?

[Michael (Passmark)]

The battery information displayed is exactly what is reported by the battery system driver, which in turn is entirely dependant on what the battery and hardware battery interface is reporting back to it. Our software doesn't do anything to verify these values (nor is there anything that can be done from the software side, you would have to attach different monitoring devices to the battery to get different information.)

That being said, figuring out a batteries current full charge capacity is always going to be a bit of an imprecise art and it's not that surprising to see it fluctuate as conditions change. What is more interesting about this value is seeing how much it drops over time with use.

ie. Right now it might vary between 10-12k so you know it's somewhere in that region, but if in a year from now it's in the 6-8k range you would know there had been a degradation.

[lineslim]

ok, thanks for your reply. I just thought it was strange that itevery time jumps between the samen 2 discrete levels depending on wheter fully charged or not.
I guess I could just conclude that the capacity did not stand up to what was promised by the seller.
Thanks