Thanks for the detailled testing and reporting. I agree with your assessment that the cells are out of balance. While I’m looking into the balancing features of our charger board, I was researching a bit into cheap and easy solutions for people to charge+balance their batteries outside of Pocket Reform in the meantime. I found that Adafruit make a bunch of little USB adapters that exactly fit our battery plugs:
- Adafruit Mini Lipo w/Mini-B USB Jack - USB LiIon/LiPoly charger [v1] : ID 1905 : Adafruit Industries, Unique & fun DIY electronics and kits
- Adafruit Micro Lipo - USB LiIon/LiPoly charger [v2] : ID 1304 : Adafruit Industries, Unique & fun DIY electronics and kits
- Adafruit bq25185 USB / DC / Solar Lithium Ion/Polymer charger : ID 6091 : Adafruit Industries, Unique & fun DIY electronics and kits
These are also available at several resellers around the world and cheaper than replacing the batteries themselves. Could this be an option for you to try and fully recharge both cells and then plugging them back into the device?