Standard 9V Rechargeable Lithium Ion batteries. Charging is very fast,Capacity 850mAh,Max output current 2.3A,The 9v lithium battery cycle life can reach 2000 times.The energy of 1pc Hixon 9V battery can equal 710pcs 600mAh 9V alkaline batteries at least and can last 20% longer than other batteries. Safety & Top High Performance-9V Li-ion Batteries are built with smart protection and CE, RoHS, MSDS Certified, 100% brand new and high quality! It is recommended to fully charge the batteries before the first use,it may reach top performance after 3 cycles of full charge and discharge.