Our Portable Energy is a revolutionary battery product design for digital camera, PDA, camcorder, MP3 and CD players. The 5V-USB and 7.4-DC ports mark it the most friendly power source for your digital products. For an average user, this product bears rich functions as a substitute power supply to extend the life of the personal electronic collections. For the business professionals, as an alternative energy source, Our Portable Energy simply brings much needed extra strength in the mobility. The Portable Energy works as an all-in-one, smart energy source with its wide compatibility for portable electronics devices. Specifications Batteries:Lithium-Ion Output: DC-7.4V/1000mA USB-DC-5V/700mA Capacity: 4000mAh, 3.7v Input: DC-8.4V(110v-220v changer included) Size: 5.47*2.95*0.43inches Net Weight: 5 Ounces Working Temperature: 14F~122F Charging Time: Approx.6 Hours