Power various electronics, including flashlights, camping lanterns, and much more, with this 21700 Rechargeable Li-Ion Battery from Fenix. The battery features 3.6V of output power, a 5000mAh capacity, and an 18Wh rating. With its higher capacity, the battery delivers a longer life to electronics. A circuit with a durable steel shell is built into the anode to protect against overcharging, short-circuiting, and overheating. It is designed with pressure relief vents that expel waste gas when a short-circuit occurs to prevent the battery from exploding. The durable battery can be charged up to 500 times.