Is it okay to leave the car key inserted in the car all the time?
4 Answers
Leaving the car key inserted in the car all the time won't affect the vehicle, but it's not recommended for safety reasons. The basic components of a remote key consist of the following two points: 1. Transmitter: Composed of a transmission switch, transmission antenna, integrated circuit, etc., containing an identification code storage circuit and amplitude modulation circuit, with a button-type lithium battery installed on the opposite side of the circuit. The transmission frequency uses radio waves, and the transmission switch button sends a signal once each time it is pressed. 2. Receiver: After the transmitter sends the identification code using shortwave modulation, it is received by the car's shortwave antenna and enters the shortwave high-frequency amplification processor of the receiver's electronic control unit through a distributor for demodulation, where it is compared with the identification code in the demodulator.
Last time when I helped my neighbor move his car, I noticed the key was still in the ignition. It immediately reminded me of my colleague's painful experience. That guy forgot to pull out the key when he went to the restroom at a service area, and when he returned a few minutes later, he found the car window smashed. Although no valuables were stolen, replacing the window glass alone cost him over 800 yuan. Actually, leaving the key in the ignition for a long time is most harmful to the battery. Once during a camping trip, we tested it: listening to music with the key in the ignition while the engine was off. In three hours, the battery voltage dropped from 12.6V to 11.3V, and we ended up needing a jump start from another car. Now I’ve developed a habit: I always pull out the key and close the windows when getting out of the car, especially for short stops like picking up a package at a convenience store—both to prevent theft and protect the battery.
Our old man always says driving nowadays is like taking care of a child, especially when it comes to the car key issue. He used to leave the key in his manual transmission old car out of habit. Two winters ago when temperatures dropped below minus ten degrees Celsius, he left the key half-turned in the ON position overnight, which completely drained the battery by next morning. Not only did it cost him 200 yuan for emergency jump-start service, but it also shortened the battery's lifespan. Actually, when the car key is in the ON position, systems like the body control module, anti-theft device, and instrument cluster continue drawing power, putting extra strain on the battery during winter. It's recommended to develop a habit of removing the key within 30 seconds after parking, and always double-check door locks by pulling the handles before leaving.
When I first bought a car, I also thought it didn't matter to leave the key inserted after turning off the engine, until I was startled by the dashboard flashing in the middle of the night. The mechanic told me that keeping the key inserted for a long time can easily burn out the steering column lock module. A friend's B-class car cost over three thousand to replace it. Especially for models with keyless start, leaving the key within the sensing range can easily trigger false alarms from the anti-theft system. It's safest to take the key out and bring it with you when parking. Don't find it troublesome even for temporary stops—car thieves nowadays specifically target such vulnerable vehicles. Last week, I witnessed a car in the neighborhood being tested by door pullers, and the owner narrowly escaped a disaster.
