I just bought a new NewerTech 7200 mAHr battery to replace my PowerBook Pismo's original battery which finally died last week. The new battery is lasting about six hours of light use or about four hours of heavy use which is excellent and a big jump from the one hour that the original battery was down to this past year. The original battery lasted me five years and three months. I mostly use my computer at my desk but also use it somewhere else for several hours probably three times a week so the battery got a regular workout. I hope this new battery lasts as long (or longer, I can dream).