About this item The smart charger features a chip control system that automatically stops charging once the battery is fully charged, accompanied by an LED indicator. (NOTE) only compatible with NiMH or NiCD AA and AAA rechargeable batteries. The scientific and thoughtful design of the battery charging position, combined with high-quality materials, effectively protects the battery during normal charging. Charge any number of AA AAA rechargeable batteries to simplify your charging process. It is recommended to use a 5V/2A plug. With a USB input interface, you can charge the battery using a laptop, car charger, mobile phone charger, etc. The charger employs a trickle charge method to extend battery life and charges up to 99%. Please read the instruction manual carefully before use. Dimensions: 3.1 x 6 x 1.1 inches.