I have the same question. First off, I'm pretty sure my mouse is out of warranty. (I have an inquiry into support, but I think I've had it longer than 3 years.)
My mouse no longer makes it through a full work day. I think it is time to replace the battery.
Thanks to the information in these threads I have identified the battery that I need. I cannot see how to get the mouse apart. There are no obvious latches or fasteners (that I can see anyway.) I tried gently prying on the bottom near the charging contacts but it did not budge and I was reluctant to apply too much force. I also wondered if there are screws under the slider pads, but those don't seem to want to come off.
Any help with this would be appreciated.
And yes, I know I would void my warranty. I think it has already expired.
Part # on my mouse (if it matters) is 852152-0100.
It is a really nice mouse and I'm not interested in upgrading.
The screws are under the back 2 feet and under the label. The label you can just feel for the holes and press thru with a screw driver. For the 2 feet, you can either peel them off (and buy replacements or re-glue the old ones back on), or just press the screw driver thru the center of the feet.
-Richard L. Owens, author of the uberOptions mod for SetPoint. Unlock the options of your SetPoint-controlled device! mirror