Hooking up a DC portable air conditioner directly to your car's cigarette lighter is generally not practical or feasible for a couple of reasons.
Power Requirements: DC portable air conditioners are typically designed to be powered by 12-volt DC power sources, which is the voltage output of a car's cigarette lighter socket. However, the power output of a car's cigarette lighter is limited, usually ranging from 10 to 15 amps. Most portable air conditioners require much higher power levels to operate effectively, often in the range of hundreds or even thousands of watts. The limited power output of the car's cigarette lighter socket may not be sufficient to power a full-size air conditioner effectively.
Cooling Capacity: Portable air conditioners designed for home use are generally much larger and more powerful than those that can be effectively powered by a car's cigarette lighter. The cooling capacity of a standard portable air conditioner designed for home use is intended to cool a small to medium-sized room, and it would not be sufficient to cool the entire interior of a car.
Heat Dissipation: Portable air conditioners generate heat during operation, which is typically vented outside through a hose or exhaust. In a home setup, the hot air is expelled through a window or a specially designed vent. In a car, it would be challenging to manage the heat dissipation effectively without causing potential safety hazards or damaging the car's interior.
If you need to cool your car during hot weather, consider using the car's built-in air conditioning system, which is specifically designed for automotive use and is more effective at cooling the interior of the car. Portable air conditioners are better suited for indoor spaces where you have access to a suitable power outlet and ventilation options.