1. Please use the required battery charger which is with Over-charge protection to charge the battery, the max voltage output is 4.25V
2. When charging the batteries, please put them in an open space and steer clear of any inflammable goods such as Carpets, sofa, bed and and the like.
3. Please do not use high current USB adapter charger that upper than 2A to charge the battery.
4. When changing the battery, do not pull hard when the battery is stuck, in a different way you can also destroy the wire of battery and its inner structure, so that it will lead to battery fire when charging!
5. If the battery swells, please discard it and do not use again!