What Happens When Your Key Fob Battery Is Dead? How Do You Fix It?

Your key fob is one of those small luxuries that you never do think about - that is, until it breaks. It controls everything from unlocking your doors to opening the windows on some models, so it becomes part of your daily routine. What happens when your key fob battery is dead? When the battery dies, don't worry. Most issues, like a dead key fob battery, are simple to fix on your own or with a quick visit to Arrowhead Imports as your BMW, Audi, and Volkswagen service mechanic in Peoria, AZ, for example. 

Learning about what to do when your key fob battery dies and how to deal with the situation can be a time-saver, money-saver, and stress-saver. Thankfully, most problems related to the battery are very easy to resolve. Even if the problem isn’t immediately fixable, there are alternative ways that allow you to get back behind the wheel.

Warning Signs That Your Key Fob Battery Is Dying

Your key fob batteries will not usually die without warning. Your car will usually offer many clues that the time has come to change. The most obvious dead key fob battery symptoms include reduced range - you'll be required to be nearer your car before the fob will work properly.

It may also exhibit variable performance. Sometimes the fob will work perfectly, sometimes the buttons will need to be pressed multiple times, or they will need to be pressed more forcefully than usual. Many newer vehicles will also display a "key fob battery low" indication on the dash, so you get a warning before the battery dies.

In the case that your vehicle is taking longer to identify the fob as it gets closer, or the engine won't turn on even as the fob is within the car, then those are absolute signs that the battery is very low.

Next Steps When Your Fob Stops Working

When your key fob simply won't cooperate, don't leap to the worst conclusion that you're locked out. Nearly all key fobs contain a hidden mechanical key that will unlock your door manually. Look around your fob for a small switch/slider mechanism/button - a push or slide there, and the physical key will be available.

Once you've gained access to your car, you're usually still able to turn the engine, even if a key fob dead battery situation occurs. Most vehicles enable the use of pressing the fob up against the start button, which can trigger the backup proximity sensor so you're able to turn the engine.

Replace the Key Fob Battery

Replacing a key fob battery is usually a straightforward five-minute job. Most fobs use common batteries like CR2032, CR2025, or CR2016, which cost just a few dollars at any store.

To change the battery, open the seam on your key fob gently with a small flathead screwdriver or coin. Take note of the orientation of the old battery before taking it out - the positive and the negative sides must face the proper orientations as the old battery is being replaced with the new.

Put the new battery in the fob and check that all the buttons are operating. Locking and unlocking should be operational immediately, although some settings may need reprogramming.

Manual Door Access Methods 

In case your key is not found, or your fob lacks a hidden key, then consult your owner's handbook regarding other access methods. There are some car designs that contain their hidden key slot around the door handle, usually located under a small cover or behind the handle.

Certain high-end vehicles even include smartphone applications that open doors even if the key fob fails. If you've had digital backup systems installed such as this, they're the ultimate lifesavers during emergencies.

Be Ready to Handle Subsequent Failures

Batteries in key fobs last about two to four years, depending on use. It may be worthwhile to replace the battery proactively if your fob is getting to be this old, particularly before road trips or during severe weather, where being stranded would be most inconvenient.

Have an additional battery on hand that can be kept inside your glovebox or purse. These little batteries do not occupy much storage, but they become your best friend during emergencies. Ensuring that your key fob gets proper maintenance prevents you from being left high and dry after the battery goes dead.