ON THE WAY&reg;4Pcs 18650 3.7V 5000mAh Li-ion Rechargeable Efficient Battery Yellow with 18650 Battery Charger and Touch Stylus Pen 4x ON THE WAY18650 5000mAh 3.7V Rechargeable Li-Ion Powerful Battery Cell for LED Flashlights, Rechargeable T6 LED Bulb Bicycle Bike HeadLight Flashlight Lamp Light. 3.7-4.2V Li-ion Cordless Charger Dual Slot with LED Indication can charge 1 or 2 18650 battery at a time. No memory effect and longer storage life than NiMH Batteries, can be recharged and discharged anytime. Can be charged over 500 times. Holds 85% charge over 12-month period. Only for the Flashlight Bike light and Headlamp powered by 18650 rechargeable batteries.