iBook G4 Battery suddenly dropped to 7% with no reasons
I bought it on ebay several months ago and it was worked perfectly.
But in couple week ago, the battery start to act weirdly when I use iBook G4 with fully charged to 100%. When I do another in several minutes ago, my iBook show pop up box that battery use extended battery and need to recharge. And I see my battery life dropped to 7% even I didn't open an web browser or itunes.
Even now, this battery still act like this. It can fully charge and use like normal battery but battery level suddenly drop to around 7-10%. And I check battery indicator on my battery, it still show 3 of 4 LEDs of battery level on it.
So, what is going on and how to fix this thing?
iBook, Mac OS X (10.5.8)