@jordanfranssen I assume you are looking for the RTC battery. It is on the backside of the main board
[image|3556109]
Use something like this guide [guide|10076] to get into the camera. Then remove the ribbon cables and the main board.
Of course, you can also donwload the SM from the device page [[Topic:Sony Cyber-shot DSC-S2100]] under the Documents heading. That will get you to the battery.