Key Fob Battery Low Warning Light

Key Fob Battery Low Warning Light: 4 Reasons Why It Occurs and Resolution

Facing a key FOB battery low warning light is common for vehicle owners. It is quite bothering, especially if you’re inside the car and the key fob battery light shows a low warning. 

So, how do you resolve the key fob battery low warning light problem? You have to replace the key fob battery. This simple replacement process requires opening the fob key and removing the old battery first, then replacing it. 

In this study, I’ll discuss everything about this problem, like why it occurs, how to resolve it, and what to do if locked inside. I guess you won’t mind investing 4 minutes reading this article.

Key Fob Battery Low Warning Light: Why It Occurs and How to Resolve?

When your key fob shows a low battery light, it’s important to resolve the issue. However, you can still start the car. But since it is associated with the car lock, you might get stuck for a while if you don’t know how to unlock your car door without a remote key. We will discuss it later.

Key Fob Battery Low Warning Light

First, let’s know why it occurs.

Why it Occurs?

It can occur if the key fob battery is running low on power. Let me tell you why the key fob batteries running low on power. 

It can primarily happen due to 

  1. Battery wear and tear
  2. Battery age ( Like 2 or 3 years old )
  3. Too frequent use
  4. Bad battery quality
Key Fob Battery Low

See, all the causes are quite common. Because of wear and tear, older battery, and too frequent use of the remote, it is very predictable to show low battery light.

In fact, the environment can matter sometimes. Extreme temperatures, such as too hot or too cold, can cause your battery to drain faster. So, it can reduce battery performance.

Another thing is interference from electronic devices in close proximity can also reduce battery performance. It is the potential reason our car system struggles to establish a connection.

How to Resolve?

In this circumstance, replacing the key fob battery is essential. To do so, you’re required to follow a few simple steps: 

  • Step 1: First, examine the back of your car key fob. You’ll likely find something like a switch or a latch that holds the battery. 
  • Step 2: Press the switch to open the key fob. In some cases, you might have to use your nailfinger. Look at the picture below for how to separate the two portions of the key fob.
How to Resolve
  • Step 3: Now, gently pop out the old battery using the key or a thin screwdriver.
Place the new battery

Do it sensibly. Otherwise, you may end up harming the key fob body. Some batteries might have paper adjusted with those. Do not damage those papers or anything that is with the battery. 

  • Step 4: Place the new battery.
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If you’ve done it successfully, congratulations! You have completed replacing the key fob battery and resolving the battery low warning light issue. 

If you still don’t get it, no worries. You’ll find tons of YouTube videos showing how to replace the key fob battery. Here’s one: 

Alternative Way to Unlock Car With Dead Battery Key Fob

If you’re stuck in your vehicle, and the key fob battery is literally dead, do not worry. There’s an alternative way to unlock your car. 

To do this, you have to find the mechanical key that is inside the battery. How do I find it?

  • Step 1: There’s a switch in the remote key fob. Press it. 
Alternative Way to Unlock Car With Dead Battery Key Fob
  • Step 2: Now, you’ll find a key here. Sometimes, you don’t need to press any switch. You just have to get the key out of the fob. The mechanical key might look like the picture below:
Unlock Car With Dead Battery Key Fob
  • Step 3: Now, use this key to unlock your car. 

Remember one thing. This mechanical or spare key isn’t specific for all vehicles. For some, it might need to press a switch. For some models, you may get it out by hand. You should find your alternative key information in the manual provided by the manufacturer company.

Anyway, you may search for YouTube tutorials. Search for your specific car model. If it’s a popular one, you may find a tutorial. Here’s one to give you a good idea of the mechanical key. 

How to Reset the Key Fob After Battery Replacement?

You have installed the battery. But that is not the end of the hassle. You have to reset the key now. The resetting might differ from one vehicle to another. But there’s a universal way to reset your key. Here’s how you have to do it. 

  • Step 1: Put the mechanical key into the door keyhole. 
  • Step 2:  Turn the key following a specific direction. Make the direction like this: Rotate the key to the right first, and then turn it to the left. Consider this as one full rotation. Do the rotation six times.
  • Step 3: Now, check whether the key fob is working or not. It should work by now. Your door should be successfully unlocked. 
How to Reset the Key Fob After Battery Replacement

You have done with resetting the key program. Still, if your car won’t start, that means it doesn’t find the key fob power yet. What should you do? You have to reset the key inside the car as well. Do it following the steps given below: 

  • Step 1: Locate the ignition first. That is quite tough to say precisely. Because you might have a model that might have a start button instead of a key. If so, locate the ignition.
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In some models, you’re likely to find it on the left side of the glove box. However, that’s just to give an idea. You may have a look at the manufacturer’s manual.

  • Step 2:  Repeat the same process you used to unlock the door by turning the key clockwise and counterclockwise, but this time, do it 6 to 8 times.

By doing the steps above, the key should be successfully reset all in all. Now, your vehicle should start by sensing the key fob. If you do not get it, here’s a video explaining in detail and showing how to reset the key. 

If you’ve encountered the key fob battery low warning light issue, it’s essential to address it promptly. Additionally, if you’re wondering why your battery light is on even after replacing the alternator, our articles on why is my battery light on with a new battery and why is the battery light on after replacing the alternator can provide you with valuable insights and solutions.


Here’s the place to find answers to what else you may ask.

Q: How much does it cost to replace the battery? 

It’s pretty cheap. You don’t need to call a mechanic, so there is no labor cost. You might have to spend around $10 to buy a new battery. That’s all about the cost. 

Q: Does every remote key fob have the same battery size?

No. Not every car remote key fob has the same battery size. However, CR2032 and CR2025 3-Volt batteries are common for vehicles. You will find the car key size in the manufacturer’s manual.

Bottom Line

Overall, the key fob battery’s low warning light problem is common if the battery is dead due to several reasons I mentioned. You can simply resolve the low battery issue by replacing it. 

After the battery replacement, you have to reset the key to unlock the car or to start the car sometimes. However, the resetting process might vary. 

In summary, if you see your key fob shows a low battery signal, do not worry. It’s an easy DIY solution; you don’t have to spend more than $10 for this.

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