I'd gotten a new ibook G4 battery about a year ago and its health had been fine until it hit about 200 cycles. I'm aware that lithium ion batteries will naturally diminish no matter what you do, but the capacity of mine suddenly began to drop much faster than I'm comfortable with. I had kept track of the health since I first got the battery and the program I used displayed 100% health for 200 cycles and then dropped to 73% over the next 40 cycles. In terms of how many hours it held of power, it quickly went from about six hours to four in only two months. I'm told that apple batteries in the ibook should be at about 80% health if the battery went through 300 cycles in a year, as opposed to a 73% rating and 60 fewer cycles. What concerns me is that the battery health was doing VERY well up to that point and then suddenly started dropping at a rate that could render it dead within another year. Is there anything that I can do to counter this, or is this normally what happens to a battery at some point? Thanks.