Battery Remaining % and full capacity

[jhujb]

Dear all,

I bought a new battery from IBM (6 cell) today. It seems strange. When I received it, I just plugged in to the AC power until it charged 100% (about 6 hr to charge without power on). Then I unpluged the AC power , it suddenly dropped to 94 % from designed capacity, so remaining percentage become about 43Wh. Designed full capacity is 47 Wh. Where did 6% go? There was no 99. 98. or 97%.... It just dropped from 100% to 94%

Is there anyone had same problem? is this battery defective?

Thanks.

[mattfromomaha]

Try cycling the battery to help calibrate it - run it down to ~10% and recharge to 100%, then see what it does.

[PetraM]

My 6-cell battery has the exact same problem. Didn't actually notice at the beginning that the full charge capacity (42 Wh)is way lower than the designed capacity (47 Wh). Not it has 15 cycles. And cycling the battery doesn't help at all. I even let it run as low as 0 so the computer just died and let it recharge overnight without power on but nothing's changed.

I'm taking the battery back next week. you think they'll replace it?

Petra

[jhujb]

I tried cycling the battery. But it results in same. If you have any other recommendation, please let me know.

I am curious if it is natural problem (e.g., IBM intend not to fully charge battery because of any danger or overcharged and so on).

Thanks

[t41user]

Several people at IBM have told me that the problem you describe is a common/natural occurrence. My impression is that IBM will replace the battery if its life/use time really begins to fail within the one year warranty period. If the decrease in full charge capacity correlates with a decrease in battery life, a decrease of more than 20% or 30% seems like reasonable grounds for a warranty replacement. From what the people on this forum seem to report, the more you fully cycle the battery - that is, the more you use the battery - the quicker and greater the decrease in battery life.