So I just performed this repair. On amazon they now have HS70 batteries. Some of them are wired correctly. Others tell you to swap the RED and BLACK cables on the connector. https://www.amazon.com/s?k=HS70+battery&... You pull off the cups on the RIGHT side of the headset. Remove the small screws, then GENTLY, lift the speaker off the board, and leave to the side, there is VERY thin copper cables to the right speaker. You then unscrew the PCB that the battery connects to. Take care NOT to bend the pins when removing the battery connector from the PCB and the battery. Then gently remove the battery, it is glued in. Do not puncture the battery. In my case the battery was pregnart/swollen. Then install your new battery, connect the battery cable again, carefully not to bend pins. Then install the PCB. Take care to make sure the wires/cables are in the same orientation and not tangled/routed incorrectly. Take a picture before you remove cables. Your new battery wire might be a bit short, so you may need to...