[noleli2]

Several years ago I bought a new battery for my PowerBook (for reasons that I won't get into). Recently (since installing Tiger, maybe?), my battery life decreased dramatically, but in a very odd way: it either doesn't charge the whole way, and thinks that it has, or won't discharge the whole way, and think that it has.

For example, while running on battery, it will discharge to somewhere between 20% and 40%, then drop to 0% and go to sleep without any warning. Or, while plugged in, it will start at 0% and charge to about 70%, then jump to 100%.

This is rather frustrating, particularly because it cuts about a third off my usable battery time.

I've already "recalibrated" and reset the PMU. I think I tried zapping the PRAM once, too. And I'm on the most up-to-date system.

Any suggestions?

[Ebby]

That sounds like a dead cell.

Your battery may be on its last leg.

[chucker]

Originally Posted by noleli2 Several years ago[..] Any suggestions?

How many years, exactly? And I assume it's lithium-ion? If so, don't expect to get any useful amount of capacity out of it after three years.

Your best bet is to get a new battery. NewerTech offers some higher-capacity replacements for a reasonable price.

[Windowsrookie]

my apple store sells new powerbook batteries for $100

[noleli2]

I got it September of 2003. Two-and-a-half years doesn't seem like it should be it for a battery.

Capacity Meter says that the capacity is 4274 of 4600, battery status is "excellent" (93%).