Solder the header strip to the controller board (except for the relay module), then solder the green LED to D1 and the red LED to D2. Next, solder a 220 Ω resistor to R1 and a 4.7 kΩ resistor to both R2 and R3. Solder the PH2.0 connector to the board, and then solder the XT30 connector to the board.
If your relay module does not use the header strip, solder wires directly and connect them to the relay module. The top pin is 5V, the middle pin is GND, and the bottom pin is the signal pin.
Install the modules onto the board. When installing the TB6612FNG modules, ensure the capacitor faces the right-hand side (both GND pins should face the left-hand side), and the USB connector for the BackPill faces the left-hand side.
Ensure the TB6612FNG modules are installed correctly, as incorrect installation may cause them to explode.
Solder the 18650 battery case to connect the batteries in series. If additional batteries are connected in series, connect them to the battery protection board as instructed by the manufacturer.