I think some might be the rechargable type, but on mine it's a standard CR2032 - however it's soldered down so a little bit of surgery is required to replace it. If you're not pretty handy with a soldering iron I'd recommend leaving it in somewhere to get replaced, and preferable replace it with a CR2032 battery holder so the next time you can do it yourself.
Also, a diode failed on my 1260 not so long ago, meaning that when I replaced the battery, the new battery was dead in a few days.
