What happens if the spare car key is not used for a long time?
4 Answers
If the spare car key is not used for a long time, it will automatically drain the battery, so the battery should be removed when not in use. The method to replace the car key battery is as follows: 1. Remove the mechanical key; 2. Insert a flat-head screwdriver into the bottom "open" position and pry it up and down; 3. Once a gap appears, use the screwdriver to pry open the key along the gap; 4. Remove the old battery and replace it with a new one; 5. Reassemble the key. The working principle of a car key is: it emits a weak radio wave from the owner, which is received by the car's antenna. After the electronic controller identifies the signal code, the system's actuator performs the action of locking or unlocking. The functions of a car key include: 1. Remote locking and unlocking of the door; 2. Press and hold the lock button after turning off the engine to close the windows; 3. Press the horn-shaped button to locate the car.
I’ve also experienced leaving a spare car key in a drawer for an extended period—over two years without use—and when I finally took it out, the remote function was completely unresponsive. Pressing the buttons yielded no reaction at all. A drained battery is the most common issue, especially with CR2032 coin cells, which lose charge quickly over time. Additionally, the circuit board can oxidize or rust, leading to short circuits. As for the mechanical key part, if exposed to humid air, the lock cylinder may seize up, making it extremely difficult to turn. Now, I’ve developed a habit of testing the spare key every few months: pressing the buttons to check if the lights still work and turning the key to ensure smooth operation. If the battery dies, replacing it promptly solves the problem. However, neglecting it for too long can lead to an awkward situation when you suddenly need the key in an emergency. It’s best to keep a spare battery on hand as a precaution—safety always comes first.
From my personal experience, if a spare key is left unused for a long time, the remote control battery will almost certainly run out of power, affecting signal transmission. Circuit aging is also a common issue; after being stored for a year or more, the internal contacts of the buttons may corrode, or the circuit board may oxidize due to moisture, rendering the buttons unresponsive. Even worse is the mechanical key—if stored in a non-dry environment, the lock cylinder can rust and jam, making it impossible to open the door in a critical moment. I used to check it every six months, replacing the battery in advance and gently turning the key for maintenance to ensure it was always ready for use. I recommend storing the key in a cool, dry place, avoiding high temperatures or humidity to slow down wear and tear, which can extend its lifespan and reduce unexpected troubles.
Leaving the spare key unused for a long time may cause the remote control function to fail, mainly due to battery depletion or possible poor circuit contact. I make it a habit to take it out and test it every quarter, pressing the buttons to see if the lights come on, ensuring it can unlock the vehicle. The storage location should be dry and well-ventilated to prevent the mechanical key from rusting. If not checked regularly, it may not work when needed, affecting travel safety, so simple maintenance can prevent major issues.
