Features: The module can switches between external power supply and battery 2 power supply (no delay), for power supply such as low-power equipment. It can start automatically during power outages and Charging automatically during incomings calls. This module combines four practical functions: lithium battery charging, lithium battery Protections, boost output, and UPS switching. It is also equipped with USB charging interfaces, which directly inputs DC5V to Charging the lithium battery. The two-color LED indicates the charging status, and the green light is on when charging, automatically stopping charging. UPS function: When the power supply power, directly supplies power to the load through the boost circuit and charges the lithium battery. But when the power is cut, the automatic starting battery supplies power to the load through the boost circuit. Boost circuit: up to 20W, up to 15W, boost circuit, 12A high current MOS, efficiency up to 96%, module power consumption 25MA, optional 5V/9V/12V output. The USB port and the 5V+and 5V- port are external power supply port, and you can choose one of them. USP+and UPS as output. battery box on the back and connect the 18650 lithium battery. It can also connecteds to other 3.7V lithium batteries. Specifications: Materials: Plastic Circuit board: 88x42mm Styles: 12V, 9V, 5V(optional) Package Includes: 1PC 18650 Lithium Battery Charging Module note: Please allow 0-1cm error due to manual measurement. please makes sure you not mind before bid. Due to the differences between different monitors, the picture may not reflect the actual of the item. Thank you.