Crucial tips ?
1. Please use the specified battery charger which is with Over-charge protection to charge the battery, the max voltage output is 4.25 V
2. When charging the batteries, please put them in an open area and keep away from any flammable products such as Carpets, couch, bed and etc.
3. Please do not use high current USB adapter battery charger that higher than 2A to charge the battery.
4. When changing the battery, do not pull hard when the battery is stuck, otherwise you might ruin the wire of battery and its inner structure, which will trigger battery fire when charging!
5. If the battery swells, please discard it and do not use again!
4-in-1 Battery Charger: Input: 5V-2A, Output: 4.2 V
Battery: 3.7 V 650mAh, 2.41 Wh
Battery amount: 4 Pcs