Battery trouble

I have a g4 ibook. I usually use it plugged into a wall jack. However I sometimes take it around the house or into the yard, or book store, etc..... Lately it seems my battery hasn't been fully charging, or draining rather quickly. After leaving it plugged in overnight, and fully charged, i unplug it and my battery meter starts dropping immediately. now i know thats normal, but it's how fast it drops that worries me. I barely get 45 minutes to an hour out of a full charge. I just unplugged it when i started typing this post and I am already down to 49 minutes left. All I have been doing is typing here. I tried resetting the pmu. If I press the button on the bottom of the book, all 4 battery lights light up. 46 minutes left now, after 2 sentences. Sure I know i could turn down the screen brightness and all that stuff, but it doesnt seem normal for the charge to run down so quickly no matter whats running. Alll I am running is mail in the background and safari. Anyone have any ideas as to whats wrong? Any way to reset the battery?

I know you've been around on the forums for awhile, so you've probably though of this, but....

Has this started recently and very quickly, or has it been a gradual decline?

And have you been draining your battery at least once a month in the past?

Thanks jn4, I usually let the battery run down at least once every 3 weeks or so, usually just leave it on overnight and by morning its asleep. I spend 90% of my time plugged in, so i am not sure if this happened suddenly or gradually over time. the ibook is still covered with applecare so i may take it in for diagnostics, but the apple store is at least 75 miles away.

Try this. Unplug the cord from the laptop and the wall, and leave the cord set for ten minutes. Also, take the battery out of your iBook. Now put it back in, and plug everything back in. See what happens.

There's a thread in here somewhere about tips for your iBook or Apple computer, where you can reset the power thingy. The fact that your battery says it has full power, but your Mac thinks it doesn't suggests it's getting confused. Apparently doing this reset can help.

how old is your battery? perhaps it just ran out of juice

tried resetting the battery,no luuck. The battery is less than a year old.Still under applecare, but the nearest store is 75 miles away which doesnt help me much, lol.

Have you checked if the battery actually is NOT out of power?....check how long it works for. Then you know if it's the system rather than the battery.