A:Answer Hi MagnumPI, For replacing the batteries, it is recommended to have it done by an authorized servicer. If the batteries of the wireless headphones will not hold a charge, you may follow the troubleshooting steps provided on this link. https://us.en.kb.sony.com/app/answers/detail/a_id/40773/p/40940,41870,70266/c/65,66/kw/not%20working -Jerome