UniEnergy Technologies Battery » How Much Does It Cost to Replace Car Key Battery?

How Much Does It Cost to Replace Car Key Battery?

Keys are one of those things that are incredibly simple but also easily upgraded. While traditional keys still reign supreme, we’ve been developing new car key technologies to make life easier and improve your driving experience.

These advancements come with a few downsides, and, while it only happens every 2-3 years (on the low end), a dead battery nullifies all those fancy features. In some cases, it may leave you unable to start your car like normal and worried about how you’re going to get where you’re going.

In this article, we explain car key battery replacement costs and the difference between doing it yourself and paying for a professional replacement. We’ll also key you in on some signs your old battery is on its way out and what you should do if it happens.

Cost to Replace Car Key Battery

Replacing your car key battery is a much simpler process than a whole key FOB replacement, and the cost doesn’t vary much from doing it on your own to paying for a professional replacement.

In either situation, expect to pay less than $10 for the new battery, but understand the differences in what needs to be done.

The DIY Route

Most people opt to swap out their own car key. The process isn’t labor intensive and it doesn’t require extensive knowledge, and it usually takes less than a minute to do the whole swap.

Because there is little difference in the price between having a pro do the swap and doing it yourself, people usually prefer this method because you can just have the batteries sent to your home and don’t need to run out for a whole new mission.

In some cases, the DIY route is cheaper (usually with more complex car FOBs).

Professional Replacement

The reason professional replacement runs about as much as replacing your car key battery yourself is that professionals tend to do it for free with a battery replacement.

This happens most often with specialist stores, like battery supply stores, electronic stores, or your local manufacturer’s parts department. You may pay a bit extra for a single battery from these locations, but it rarely exceeds that $10 price.

Calling a locksmith always results in an extra charge, even if they only need to replace your car’s FOB battery.

Professional replacement is more expensive for luxury brands, but it may also be more necessary. You also need to follow this route if your smart key FOB requires reprogramming, usually if it’s been dead a while or if there’s a different issue in place.

Warning Signs You Need a Key FOB Battery Replacement

While many modern car key FOB batteries now last 4-6 years, there are plenty of signs that pop up before it cuts out completely. This includes any deviation from normal operation, usually:

  • A reduction in range
  • Delayed responses
  • Multiple clicks to accomplish tasks
  • Limited operations

1. Reduced Range

The earliest sign of a dying key FOB battery is reduced range.

Depending on your specific key FOB, the typical range is anywhere from 30 to 60 feet. You probably have a good idea of how close you need to get for your key to work.

Anything less than the typical range is an issue. The key cuts down on range to try to conserve battery, and this may continue to diminish for months. Instead of playing a guessing game, it’s important to replace the battery before things get worse.

2. Delayed Response

Delayed Response

Before you install a new key FOB battery you’ll notice a delayed response from the one on its way out. You might stand right next to your car, click the button to unlock, and then grab the handle to find it still locked.

Then you hear the car unlock the doors while you’re tugging at the handle, forcing you to start over. In some cars, your headlights won’t blink or your car won’t beep like normal either.

Your key FOB should lead to immediate responses, and if something feels off-kilter it probably is.

3. Multiple Button Clicks Needed

As your key FOB battery loses its charge, you need to click multiple times to supply the power needed to complete the action. This usually applies to more intensive actions, such as starting the car.

Each time you click the button, you feed the key FOB a bit of juice, and only after you make multiple attempts does it have the energy to convey your message.

4. Limited Operation

At the end of its life, a dying car key battery starts cutting out certain operations completely. This usually applies to more powerful operations, such as starting the car.

In some car keys, the limitations differ depending on a factor of things. You may need to be right next to your car or hold the FOB right up to your start button for anything to happen.

This is your last sign to replace your car key battery before it goes out completely.

What to Do if Your Remote Battery Dies

Regardless of why your remote key battery dies, you should:

  • Find a backup key option to support you until you replace the battery
  • Determine where you’re getting your car key battery replacement
  • Follow your instruction manual (if replacing it on your own)

Replacing the battery as soon as possible not only returns you to normal operation, but it reduces the chance of losing your key FOB or needing to reprogram the remote.

1. Find a Backup Option

The most obvious backup option is another car key you have, whether that’s a physical key or another remote already programmed to your car.

Those with remote start key FOBs should know how to access the backup key in the remote. Look up your specific key FOB manual to learn how to procure this (usually using a release switch), then find the hidden keyhole in your car.

Your car owner’s manual tells you where this is, usually hidden under trim by the driver’s door. Remove it carefully to uncover a physical keyhole that lets you get in and lock your car while your key battery is dead.

You need to find your backup slot to place your dead FOB to start your vehicle. This is noted in your manual, and once you dock the dead FOB you should be able to start like normal.

2. Find a Key Battery Replacement

First, determine whether you want to replace the battery on your own if you would rather start with a professional replacement.

If you’re going the DIY route, find the exact same battery from pretty much any retailer. The most convenient include:

  • Walmart
  • Amazon
  • Any local battery store
  • Auto parts stores (such as AutoZone or O’Reilly’s Auto Parts)

For professional replacement, go to your vehicle manufacturer’s parts department or a store that specializes in batteries. Both of these places can help you track down the exact battery you need, and they usually replace it for free as long as you purchase the battery from them.

3. Follow Your Instruction Manual

If you’re doing it on your own, we suggest finding your car’s instruction manual or a specialized video guide for the exact steps needed in your situation. These usually look like using a small screwdriver to reveal the battery compartment, then swapping them out.

It’s a good idea to keep at least one extra battery and the necessary tools in your car so you can replace your battery right then and there. Not only does this protect you in an emergency, but it helps you remember where everything is when that time comes.

Types of Car Keys (and How They Affect Battery Replacement)

There are three basic types of car keys:

  • Traditional keys (no battery, but they may have a chip)
  • Keys with a remote FOB
  • Single FOB keys (keyless)

These affect battery replacement and may require additional steps or considerations with a dead battery.

Types of Car Keys

1. Traditional Keys

Traditional keys are what most people still think of when it comes to a car key. This is your metal key with teeth that allow you to unlock and start your vehicle.

Newer keys may have a chip embedded in the plastic of the key head. This talks to the transponder in your instrument column to prevent theft via hot-wiring.

2. Keys with Remote FOB

Keys with remote FOB are a mix of old and new technology. Keyless entry has been a thing since the late 1990s, and the remote usually lets you lock or unlock the car and control the remote.

These batteries last longer because they accomplish less, and they’re simpler to swap out.

3. Single FOB Keys (Remote Start)

“Keyless” car keys still have a physical backup key, but they resemble only a remote for keyless entry and starting. They’re quickly gaining popularity, but require more effort for reprogramming and battery replacement.

These single FOB key batteries go out faster than simpler designs, but reliability isn’t an issue. Manufacturers wouldn’t throw out a design that leaves you stranded.

What to Do if Your New Battery Doesn’t Work

If you replace your car key battery and nothing changes, you should make sure the key battery was the issue. This is easiest if you have a backup FOB you can test out.

Make sure your new battery is installed correctly (it’s easy to install button batteries upside down) and properly charged. You can try another battery if you bought a multipack or you’re still at the store.

In some extreme cases, you need to reprogram your car key. That’s a whole new venture with manufacturer specific requirements, but expect to take a trip to your vehicle manufacturer at this point.


Replacing a car key battery shouldn’t cost more than $10 in most situations, so choosing between professional and DIY installation usually revolves around convenience.

If you’re unsure, go the professional route the first time and use that experience for future battery swaps. Comment with any questions or concerns you have about replacing your car key battery.

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