Find a battery of the same size or a little smaller and put it in. batteryjunction.com has a big selection. You might have to solder some wires on or similar.

Find a battery of the same size or a little smaller and put it in. batteryjunction.com has a big selection. You might have to solder some wires on or similar. Adafruit.com has some with JST connectors which have a good chance of being what your GPS uses inside, but they don't have that wide a selection of cell sizes, so it's iffy. Anyway the first thing to do is open up your GPS and look at the cell. In the old days you could usually find a phone battery the right size on places like dx.com, but replacement phone batteries aren't that common any more.