Treo 180 Battery
The battery on my old Treo 180 is nearing its end. While the phone has never great on battery life, I’m now only getting a bit over a day on standby and some minor usage.
The battery, though, looks like it’s easy to replace: Handspring Treo Battery Installation Guide. About $30, and they throw in a screwdriver for you. Note that this battery seems to have a bit more capacity than a direct replacement (1000mAh vs. 750mAh). I’m not sure if a higher capacity battery can be crammed in there.