The car mode in ZERO BREEZE Mark 2 is a feature designed to prevent draining your car battery completely while in use. The default mode automatically shuts off the air conditioner when the power supply voltage drops below 18.6V.
To enter car mode, simply press and hold the "+" and "-" button for 2 seconds. The tail indicator light will turn purple, indicating that you are now in car mode. In this mode, the air conditioner will automatically power off when the power supply voltage drops below 22.3V, preserving your car battery.
To switch back to the default mode, simply press and hold the "+" and "-" button for 2 seconds again.