parking air conditioner refers to the continuous operation of the air conditioning system with the on-board battery DC voltage supply (12V/24V/36V) when parking and waiting and resting.

Due to the limitation of on-board battery power and poor user experience when heating in winter, parking air conditioners are mainly simple cooling air conditioners. In general, it includes a cooling medium conveying system, cold source equipment, terminal equipment, etc., and other auxiliary systems. Mainly include: condenser, evaporator, electronic control system, compressor, fan and piping system. The terminal uses the cooling energy supplied to specifically respond to the air condition in the cabin in order to provide a comfortable resting environment for the truck driver.

Because the parking cooler connected directly to the truck battery, many master drivers worry that the air conditioner in the parking lot will stay cool for a while and become embarrassed if it is not on while driving. Therefore, the “switch-off voltage protection function” of the parking cooler is particularly important.

The turn off voltage of most brands of parking air conditioners on the market is fixed and the protection voltage is generally set between 21 and 22V. If the cut-off voltage of the parking cooler is set to 21.5 V, the battery will discharge and the voltage will drop when the parking cooler is used. When the voltage reaches 21.5V, the parking air conditioner will alarm and stop.

After the battery has been used for a period of time, it will gradually deteriorate. In addition to increasing the internal resistance, there are problems such as virtual power, high voltage, and low power. Battery aging can also easily lead to current instabilities. After the battery ages, the actual measured voltage may be higher than the actual output voltage, resulting in the car not starting. It is therefore necessary for the auxiliary air conditioner to…