- After confirming the battery type, press and hold the button for 2 seconds to enter the string number 2 / voltage setting. The LED stays on and the string number / voltage LED flashes. - Press the button to set the battery line number or voltage. For valid values, refer to the option table. - Press and hold the button for 2 seconds to enter the setting state. The mode light (type battery 1) flashes and the string number light stays on. Short press the button to select the battery type. - After setting, press and hold the button for 2 seconds to save the data and return to the 4 power status display, or wait 5 seconds for automatic return. Use scenarios - Field service or installations where different tools require different battery configurations; quickly switch battery type and voltage on the device. - RC hobby, drones or robotics projects needing precise voltage settings to match motors or controllers. - Lab or test bench environments that require switching between multiple battery configurations without re wiring.