Lithium battery pack to replace the 9V alkaline battery, Normal voltage: 7.4V Normal capacity: 600 or 650mAH Battery type rechargeable li-ion Discharge cut-off voltage: 5.5V Charge current: 120mA Charge voltage: 8.4V Dimension: Max 46.0* 27* 17.5mm Specified charger is also available. ShenZhen HengYu Energy Technology Co., Ltd Tel: + 86-755-86006067 Fax: + 86-755-26585593 Email: jessie@ hengyutech.com jessiezhou1123@ gmail.com Website: www.hengyubattery.com