The Surefire 123A Rechargeable Batteries (SFLFP123) are Lithium Iron Phosphate batteries which can be resused and can save you a lot of money over 123A lithium batteries. The 123A Rechargeable Batteries do have significantly less run time than their disposable counterparts. SFLFP123 cells are safe to use, cost-effective, and they retain approximately 80% of their original capacity even after hundreds of charging cycles. The included smart charger can fully charge two batteries in three hours. The charger uses a USB connector. Pack includes 2 batteries.