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  • Max Kelly

What Battery for My Car Key?

When the battery in your car key starts to lose its charge, it's important to know the right replacement battery for key fob to keep your car key functioning smoothly. In this Keytek® Auto Locksmiths blog, we'll guide you through the process of selecting the appropriate key fob batteries.

What Happens When Your Car Key Battery is Low?

A dead battery for car key fob means that the car key is unable to transmit any signal to the car’s receiver. This will mean the car is unable to be unlocked using the key remote function, and keyless entry cars will be unable to start.

If you suspect your car remote battery is low on charge, you may notice the following:

  1. The car key fob may start to become unresponsive, and it may take several clicks for the remote function to be carried out.

  2. The range may decrease; you may notice you have to be close to the vehicle for the signal to transmit.

  3. In cars with push-button start, the car may not recognise a car key fob when the battery is weak.

How Do I Know What Battery My Car Key Needs?

The most common batteries for keys for a car are CR2032 and CR2025 3-Volt batteries.

To find out what battery for my car key you can check the cars instruction manual, where this information will be listed. Alternatively, you can open your car key fob and check the key fob batteries.

How Do I Know If My Key Fob Needs a New Battery?

A CR2025 battery in a car key fob may last up to 3–4 years before needing replacement.

However, the CR2032 battery in a car key fob may last up to 4–5 years before needing replacement.

The CR2025 battery generally has 165 mAh, while the CR2032 battery has 225 mAh. Milliampere-hour (mAh) shows the charge capacity of a car remote battery and how long it can be powered for. Because the CR2032 battery has a higher mAh, it has a slightly longer car key fob battery life than CR2025 batteries.

If you are thinking of attempting to replace the key fob batteries by yourself, read our blog on How to Change a Car Key Battery, where we can give you some information!

Where to Get Car Key Battery Replaced?

If you are unsure of the replacement battery for car key fob and where to get car key battery replaced, we at Keytek® Auto Locksmiths can help!

Book an appointment or call us to get immediate roadside assistance.


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