With adjustable electrode, this portable single-slot battery charger can charge many types of batteries. This lithium-polymer battery charger includes programs for current and Vmax detection to prevent your batteries from overcharging. By using a USB port for charging, you can charge your batteries in the office with your computer or use a power bank to charge while on the subway. When charging the battery in reverse or charging a short-circuited one, the battery charger will not work, which protects you from potential danger. Small size and light weight, the 18650 single-slot battery charger can be put in your bag, pants pocket. FeatureIntelligent IC control, output short circuit, anti-reverse protectionThe LED light is red when charging, it is green when fully charged or empty.Power supply mode: USB DC5VInput voltage: DC 5V 1-2AOutput Voltage: DC 4.2V 500mAProduct size: 102*22*27mmCable length: about 60CMCompatible battery: 10440/14500/16340/16650/14650/18350/18500/18650/26650 etcPackage Include:1*1 Slot Charger (Battery not included)