On remark though: the original Bose battery has a thin foam gasket at the base. This foam gasket makes sure the room behind the speakers is airtight, which is essential for a clean sound. Most aftermarket batteries do not have this gasket, leading to a thumping noise when you turn up the music. This is easy to fix: with a sharp cutter, gently peel the gasket from the original battery and reinstall is on the new battery. That solved the problem for me. Alternatively, you can cut a think sheet of PE foam to fit the base of battery.