Lithium-Ion rechargeable batteries are custom fabricated to provide increased energy density and longer life. The ASP 18650 rechargeable is optimized for use in high drain devices such as flashlights. Each power cell has a PCM protection circuit to guard against excessive charge, discharge cycles. Link Cases provide protection and interconnective storage for 18650 Lithium rechargeable batteries. A case is included with ASP power cells. Additional cases are available from ASP Distributors.