The LED on charger is red when charging; when the battery is fully charged, LED turns green.
If you want to plug this USB charger to a wall adaptor to charge the battery, please make sure the output current of the adaptor is greater than 1000mAh, so as to protect the adaptor and to get a better charging experience.
IMPORTANT: DO NOT use on batteries with less than 2000mAh.
Output: DC 4.2V 1000mah
Input: DC 5V 1200mah
As with all rechargable batteries... never leave them charging unattended.