S70 is easy, it has a door on the back so it is easily user replaceable. The SL is a different animal, very much like the opening the Nevo Q50, you have to take it apart; 4 screws under the 4 feet on the back and then use an old credit card (which will get messed up a bit so use an old plastic card) along the side and bottom edges and it is very touchy when taking the two cases apart near the scroll wheel which is very easy to break. Batteries are available on eBay from Cameron Sino or anyone selling that brand.

DD