Liter energybattery 3.7V Lipo Battery 500mAh Rechargeable Lithium ion Polymer Battery 702030 with JST Connector

After my Between Pro Bluetooth earbuds stopped charging from the case, I disassembled it to find the battery had puffed to near bursting pressure after just under 2 years since purchase and maybe 250 normal charge cycles and no abuse. Sad, these are great earbuds!After researching options to replace the original internal battery by size: 9mm×15mm×40mm (500mah), I ordered the Liter Energy Lithium ion Polymer Battery 702030 that easily fit in place of the less energy dense original battery.The Liter Energy battery arrived in good shape at around 3.93v. Storage voltage is more often 3.80v, but close enough and the polarity was correct.The BMS of the original Between Pro battery was bi-directionally controlled as it had red, black, and yellow output leads soldered from the original batteries bms directly to the main board of the Between Pro charging case; I had to reuse it.On this new battery, I carefully removed the original spot-welded BMS board with some patience, all while covering the opposing terminal with tape to prevent a short circuit.I then simply soldered the original BMS board to the new battery, applied new Kapton tape for protection under and over the terminals and BMS, and a strip of 3m foam adheisive was used to hold it in its new home. The case came back to life and has now completed 3 charge cycles. Working great!

I was impressed with this product from the packaging to the product itself I was amazed. I recommend

Be sure to measure before ordering. These fit exactly as measured and work great, would definitely recommend

I unpacked it and unwittingly plugged it into one of my microcontrollers without noticing that the poles were reversed on the JST adapter. I had to cut the wires, flip it over and resolder it. It does work, though.

As soon as I connected the battery to my Adafruit Feather 32 board, it just fried it. I have used the same board with other batteries. This one just killed it.