Replacement Lithium-Ion, rechargeable 18650 batteries are available separately. This battery is designed for use with Lezyne Super Drive XL, Power Drive XL, Super Drive (2012), and Power Drive (2012) LED lights. Each battery comes in a machined aluminum tube with rubber end caps for storage and protection from moisture or grime until it is needed. All Lezyne batteries are quality tested for capacity and performance before leaving Lezyne's factory. To get the best performance out of Lezyne LED lights, we recommend only using Lezyne batteries.