3.7V Li-ion Rechargeable Battery

The 3.7V Li-ion Rechargeable Battery is a Heavy Duty capacity 18650 battery for high drain devices. With tremendous capacity and value, the Ultrafire 4000mAh 18650 is a high-powered li-ion battery that is perfect for demanding electronics such as tactical LED flashlights. These batteries feature 3.7 Volts of power and a top-of-the-line 4000mAh capacity that will keep high drain electronics running longer than competing power sources. Combined with reliable manufacturing quality and bulk value pricing, the Ultrafire 18650 is one of the best deals when it comes to li-ion power. PCB PROTECTED Each Ultrafire 18650 is outfitted with a uniquely designed PCB (printed circuit board) that functions as the brain of the battery, regulating output and intake of electrical charge. Thanks to the circuit board the battery is always safe to use and charge, as it will cut off the battery if the voltage drops below 2.5V or exceeds 4.25V. You can rest assured that your battery will perform perfectly ever