Specifications Length 5.1 in Weight 0.65 lb Capacity 3,400 mAh Voltage 3.7 volts INCLUDES ONE 18650 BATTERY The SF1850A-KIT provides an energy dense yet economical battery solution for electronic devices that use 18650 batteries. The included smart charger only takes up to three hours to charge one or two 18650 batteries in your home, office or vehicle. The SF18650A-KIT includes: one protected lithium ion 18650 3400 mAh battery, a smart charger, a 100-240V AC adapter and a 12 V DC car plug adapter. Features AC adapter with international compatibility: Input 100-240V, 50/60Hz Smart, internal microprocessor automatically terminates when batteries are fully charged. Charger algorithm provides constant-current / constant-voltage (CC/CV) charge cycle Safety design features provide protection from overtemperature, overcharge, short-circuit, and reverse polarity 12V car plug for on the road charging Charge one to two 18650s from 1.5 hours to 3 hours. Charge termination voltage occurs at 4.2V