I spoke to my father about this. He used to be a professional troubleshooter for US government high-end computers. He's also still very much a hardware hacker, having just replaced a battery in a closed GPS unit he uses for golfing. He has a bunch of professional test equipment for electronics in his workshop. Anyway, his theory is that the battery construction is much thinner now days to save weight and a small number of units will have bad batteries due to the OEM battery supplier, which is often in another country. His recommendation was to change the battery if it is already out of warranty. Personally, I wouldn't change it. However, he's the type of guy to take apart anything. He told me to share information on replacing the battery, but to me this is a mixed bag since some people may break the camera. It seems best to get the battery replaced under warranty.