funcion 4: UPS(Uninterrupted power supply):if input 5v , it will charge the battery and no use the battery power to step up ; if power failure, it will automatically use the battery power.
You can use two or more in parallel to get more output power.
Note: 1 if the load less than 2 Watt, you can input 5V 1A;if the load more than 2 Watt less than 5 Watt, please use 5V 2A for input. 2 if you want a add switch , please add it on SW pin, it can control the output, otherwise, please short SW pin. 3 the Load current should less than 1A , if you want to control greater load, please use two or more board in parallel. 4. the board with short circuit and other protection, if make a mistake and short it, please input 5v to Reactivate it 5the board has Mos components,which easy destroyed by static electricity,so Please use soldering iron with Ground wire and take anti-static measures. Tip: 1 you can use it as a power bank. 2 you can use it as a charger for lithium battery. 3 as 5V UPS for raspberry pi or other MCU