Specifications: 1) Size (L x W x H): 85 x 33 x 17.5mm 2) Input voltage: DC 3.0V 3) Output voltage: 4.2V 4) Output current: 300mA 5) Available talking time after charging: around 2.5 hours (but there are differences between different charging conditions required by phones) 6) When power is off during you talking, you can use this charger and continue to talk