Sorry, you're wrong.

Samsung Galaxy S1:

http://www.techinsights.com/uploadedImages/Public_Website/Co...

The internal battery is located at the top-right - a circular coin cell soldered to the board.

Samsung Galaxy S2:

http://i295.photobucket.com/albums/mm148/rprosperojr/IMG_120...

The internal battery is located at the center-top

Edit: In case of the SGS2 it's located next to the WLan/BT module.