Description Details: Battery type: 18500 Lithium-ion Battery voltage: 3.7V Needle protrusion：1.5-5mm Power intake: 5W Rated capacity: 1900mAh Charging input: 5V/1A Charging t ime: 3-4 hours Usege time: 4-6 hours Adjust voltage by angle Most important thing before using EP9 pen is that put the battery into the pen correctly!!!
