Question: How to charge the main control board after it is connected with lithium batteries?

Answer:

After the main control board is connected with lithium batteries, it can be charged by connecting USB cable to the computer. Whether the switch is turned on or not, it can be charged. If the switch is turned off, the charging efficiency is the highest. The red light on the left side of the lithium battery plug of the main control board is on, indicating that the battery is charging, and the blue light on the right side is on, indicating that the battery is full of electricity.