You can replace Jabra BT800 bluetooth headset's battery. it is 3.7v 140 mAh 501520 (meaning battery thickness 5mm, length 20mm, width 15mm). to open the bluetooth headset without breaking it, you need to pull of gray-black color ear hanger on it slowly. After removing ear hanger part, you will see a screw under it. Remove the screw, then slowly try to open the device by a hard plastic tool. you can unsolder the dead battery on its pcb and solder the new battery. Good luck!
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You can replace Jabra BT800 bluetooth headset's battery. it is 3.7v 140 mAh 501520 (meaning battery thickness 5mm, length 20mm, width 15mm). to open the bluetooth headset without breaking it, you need to pull of gray-black color ear hanger on it slowly. After removing ear hanger part, you will see a screw under it. Remove the screw, then slowly try to open the device by a hard plastic tool. you can unsolder the dead battery on its pcb and solder the new battery. Good luck!