Battery Gembird 18650 Li-ion
18650 3.7V Li-ion Battery Provides long-lasting energy with very low self-discharge. The integrated protective plate protects against overload, short circuit and deep discharge. Suitable for m.in use. LED flashlights, e-cigarettes, laser pens, etc. The battery life is more than 500 cycles, so you don't have to think about buying new batteries.