These are my Poly battery replacement notes - use at your own risk.
The replacement service offered by The Sound Organization (
soundorg.com) - is the route that I would use if I hadn’t already modified my Poly.
The OP and credit is from a different forum from November 2020. I used this to make my first battery change in 2021.
https://www.superbestaudiofriends.org/index.php?threads/lol-What-chord-poly-damn.10205/
Start - 25 March 2024
Cut old battery right at the base to save the connector and as much wire as possible.
Take out SD card.
Poly has four screws on back - it slides up and out on a slight angle - the Bluetooth cover has a ridge on it, be careful not to damage.
Poly - opened.
Do not remove the two screws that hold in the PCB board - the optic bar will fall out and it’s a PITA to get back in place.
Note the white battery connector - use a spudger tool to gently pry from board - it lifts up from the side opposite the wires. It will snap back in place.
Splice the new battery into the old connector.
Both the new and original battery will read between 3.7 V and 3.9 V on a multimeter. If the replacement battery is 4 V or higher, do not use.
I used tape instead of solder as I expect to do this again and there isn’t much of the original connector to spare.
To re-assemble - the optic bar lines up with the bottom hole on the Bluetooth window.
Carefully slide the Poly back into place - the back has a thread that lines up with case.
Final working system.