Hi
I have the problem with the Speaker 2 go that the batteries are dead, so I opened it.
The batteries (2) are in the back of the device. To open it you must remove the aluminium grid on back, and also on front for better access.
For the back: remove the long plastic bumber under the device, you will find 2 long openings, here you can push with a large screwdriver to loose a bit the aluminium grid. with a small screwdriver or a pin, you can open more and more the grid all along the frame. Be careful the grid is easy to warp. you will find 4 small depressions near the corners, this helps to pull the grid away (only pressed in, no glue no screws).
The 2 batteries are pressed in the plastic housing on the back. First unplug the connector, and then remove the batteries (not easy, be careful LiPo batteries are dangerous if hurt)
For better access to batteries it helps to remove also the Aluminium frame, for this you must remove the front grid, remove first the long plastic cover on the front / bottom (glued) and than same procedure as the back grid. Then you have access to 4 screws and can remove the frames.
Batteries reference:
AEC753055-2S
1250 mAh 7,4V
9,25 Wh 3201
approx dim: 53 (length) x 30 (height) x 16 (width)
Unfortunately it seems to be a specific type and for the moment I couldn't find where to buy!
If someone could help it would be highly appreciated.
Marc