How long will the car battery last if the air conditioner is turned on without starting the engine?

[AuroraDella]

If the air conditioner operates at full capacity, the car battery can supply power for about 8-10 minutes. Most household cars today have a 12V, 50Ah battery, which means a total capacity of 600Wh, capable of powering a 600W appliance for 1 hour. Here is an introduction to car air conditioning: 1. Introduction: The car air conditioning system, abbreviated as car AC, is used to adjust and control the temperature, humidity, air cleanliness, and airflow inside the car cabin to the optimal state, providing a comfortable riding environment for passengers and reducing travel fatigue; it also creates good working conditions for the driver, playing an important role in ensuring safe driving. 2. Functions: The functions of automatic air conditioning include automatic adjustment of in-car temperature and humidity, automatic control of air recirculation and supply modes, as well as operation mode and ventilation volume control.

[CarterMarie]

I once tried running the air conditioner without starting the engine while waiting in the car, and the battery died in less than half an hour, requiring a jump start to get going. It mainly depends on the battery condition. A new factory-installed battery lasts longer, while my old three-year-old battery would give out in about twenty minutes when running the AC compressor. The AC consumes a lot of power because the compressor requires over 800 watts at startup, and even the blower alone needs dozens of watts. Seasons also make a big difference—in summer, when the car interior is extremely hot, the AC has to work harder to cool, draining the battery even faster. My advice is to always start the engine when using the AC, even for short stops, since replacing a battery isn’t cheap.

[StHazel]

Battery capacity determines how long you can use the air conditioning. Nowadays, household cars generally have a 60 ampere-hour battery, theoretically storing 720 watt-hours of electricity when fully charged. However, considering that the compressor can consume up to 1500 watts when operating, plus the consumption of the air delivery system which is several tens of watts, the actual usage time is affected. In practice, the compressor starts and stops intermittently, so the duration is slightly extended. Generally, in summer when using the cooling function, a new battery can last about half an hour, while in winter, using the heater is more energy-efficient, lasting over an hour. However, if the battery is severely aged or if the car lights and audio system are also on, the duration can be halved. This kind of operation significantly damages the battery's lifespan, so I later preferred to just open the windows for ventilation.

[LeIan]

Buddy, you've hit the nail on the head with this question. After running my auto repair shop for over 20 years, I've seen countless vehicles towed in for jump starts due to this. Here's the key takeaway: For an average displacement vehicle, a new battery can run the AC for no more than 40 minutes, while an old one will likely die within 15 minutes. The crucial point is that battery voltage plummets when the AC is operating - once it drops below 10 volts, your car won't start. I always remind customers to watch their battery warning light; if it dims, shut off the AC immediately. Doing this regularly will inevitably lead to lead sulfate crystallization and battery failure. And let's not even talk about the danger of waiting with AC on during rainy days when windows might fog up. The safest approach is simply starting your engine before using the air conditioning.