Is your car key fob starting to feel a bit unresponsive? Are you finding yourself pressing the unlock button multiple times before your car finally acknowledges your command? Just like any other battery-powered device, the battery in your key fob will eventually wear out. Before you rush to the dealership or assume you need a costly key fob replacement, the solution might be as simple as swapping out the battery. But What Battery Do Key Fobs Use? This is a common question for car owners, and understanding the answer can save you time and money.
Knowing what battery your key fob uses is the first step towards a quick and easy fix. While professional battery replacement is always an option, changing a key fob battery yourself is a surprisingly straightforward task that most people can handle with a few simple tools and a little patience. In this guide, we’ll delve into the world of key fob batteries, exploring the common types, how to identify the right one for your fob, and provide a step-by-step guide to replacing it yourself.
Decoding Key Fob Batteries: Common Types and Sizes
When it comes to what battery do key fobs use, the most frequent answer is a coin cell battery. These small, round batteries are ubiquitous in compact electronic devices, and key fobs are no exception. The most common type you’ll encounter is the CR2032 battery.
The CR2032 battery is a 3-volt lithium coin cell known for its long life and reliability. Its popularity stems from its balance of size and power, making it ideal for small devices like key fobs. The “CR” designation indicates it’s a lithium battery with a round shape, “20” signifies a 20mm diameter, and “32” represents a 3.2mm thickness.
However, the CR2032 isn’t the only battery you might find in your key fob. Depending on your car’s make, model, and year, other coin cell batteries might be used, including:
- CR2025: Similar to the CR2032 but slightly thinner (2.5mm thickness). It’s also a 3-volt lithium battery and can sometimes be used as a substitute for CR2032, though it may have a slightly shorter lifespan due to less material.
- CR1632: Thinner and smaller in diameter than CR2032, this 3-volt battery is used in more compact key fobs.
- CR1620: Another 3-volt option, even thinner than CR1632, used in very slim key fobs.
It’s also possible, though less common, to find other types of batteries in specific key fobs. The best way to determine what battery your key fob uses is to check the fob itself.
Opening a key fob with a watch knife is easy, as Mike Harris, Interstate All Battery Center manager of production and engineering shows. | Image: Mike Harris
Finding the Right Replacement: How to Identify Your Key Fob Battery
So, you need a new battery for your key fob, but how do you know what battery to buy? There are several ways to find out:
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Check Your Key Fob Casing: Many key fobs have the battery type embossed directly on the back cover or inside the battery compartment. Look closely for markings like “CR2032,” “CR2025,” etc. This is often the easiest and most reliable method.
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Consult Your Owner’s Manual: Your vehicle’s owner’s manual should contain information about key fob maintenance, including the battery type. Look for the section on key fobs or remote controls.
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Open the Key Fob (Carefully): If you can’t find the battery type externally, you’ll need to open the key fob. As demonstrated by Mike Harris from Interstate All Battery Center, this can be done gently with a thin blade or watch knife. Once open, you can visually identify the battery type printed on the old battery itself. Always take a picture of the battery and its orientation before removing it, as shown in the next section, to ensure correct replacement.
Opening a key fob with a watch knife is easy, as Mike Harris, Interstate All Battery Center manager of production and engineering shows. | Image: Mike Harris
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Online Resources: If all else fails, you can search online using your car’s make, model, and year along with “key fob battery type.” Numerous online forums and parts websites can provide this information.
It’s crucial to confirm the correct battery type before purchasing a replacement. Using the wrong battery can lead to improper function or even damage to your key fob.
Step-by-Step Guide: Replacing Your Key Fob Battery
Once you’ve determined what battery your key fob uses and have the correct replacement in hand, you’re ready to perform the battery swap. Here’s a step-by-step guide, with insights from experts like Joseph De La Rosa of Interstate All Battery Center:
Tools You’ll Need:
- Thin Blade or Watch Knife: For gently prying open the key fob case.
- Small Precision Screwdriver (1.4mm – 2.4mm): Some fobs use screws to secure the case.
- Replacement Battery (Correct Type): Ensure you have the right battery (e.g., CR2032).
- Tweezers (Optional): Helpful for handling the small battery.
- Smartphone Camera: To take pictures for reference.
Steps:
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Prepare Your Workspace: Work on a clean, well-lit surface. Having a soft cloth underneath can prevent scratches and help contain any small parts.
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Open the Key Fob Casing: Examine your key fob for any screws. If present, use the precision screwdriver to remove them and set them aside in a safe place. If there are no screws, locate the seam where the two halves of the fob case meet. Gently insert your thin blade or watch knife into the seam and carefully pry the case open. Work your way around the case, gently twisting the blade to separate the halves. Avoid forcing it, as you could damage the plastic clips that hold the case together.
Opening a key fob with a watch knife is easy, as Mike Harris, Interstate All Battery Center manager of production and engineering shows. | Image: Mike Harris
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Take a Picture! Before you remove the old battery, take a clear photo of the inside of the key fob, paying close attention to the battery’s orientation (+ and – sides). This is a crucial step, as key fob internals can vary, and this photo will be your reference during reassembly.
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Remove the Old Battery: Carefully remove the old battery. Some fobs have a small retaining clip or metal piece holding the battery in place. Use tweezers or your fingertip to gently lift the battery out. Note the orientation of the positive (+) and negative (-) sides as you remove it, even if you’ve taken a photo.
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Install the New Battery: Insert the new battery, ensuring the polarity matches the orientation of the old battery (and your reference photo). The positive (+) side of the battery usually faces upwards, but always double-check your photo. Press the battery firmly into place until it’s securely seated.
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Reassemble the Key Fob: Carefully align the two halves of the key fob case and snap them back together. Ensure the case is fully closed and all clips are engaged. If you removed screws, reinsert and tighten them gently.
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Test Your Key Fob: Press the buttons on your key fob to test if it’s working correctly. If your car responds, you’ve successfully replaced the battery!
Store manager Joseph De La Rosa at Interstate All Battery Center of Surprise, Ariz., shows how it’s done. | Video: Joseph De La Rosa
Tips for a Smooth Key Fob Battery Replacement
- Be Gentle: Key fobs are delicate. Avoid using excessive force when opening or disassembling them.
- Take Your Time: Rushing can lead to mistakes or damage. Work methodically and carefully.
- Static Electricity: While not usually a major concern for key fob batteries, grounding yourself by touching a metal object before handling the circuit board can prevent static discharge.
- Battery Disposal: Dispose of the old lithium battery responsibly at a designated battery recycling location.
- If in Doubt, Seek Professional Help: If you’re uncomfortable performing the battery replacement yourself, or if your key fob still doesn’t work after replacing the battery, consult a professional at a car repair shop or a battery center like Interstate All Battery Center.
Conclusion: Key Fob Battery Replacement Made Easy
Understanding what battery do key fobs use and how to replace it is a valuable skill for any car owner. By following these steps and taking your time, you can often revive a sluggish key fob and avoid unnecessary dealership visits or key fob replacements. With the right battery, readily available tools, and a little care, you can keep your key fob – and yourself – reliably on the go. And remember, for all your battery needs, from key fobs to car batteries, resources like Interstate All Battery Center are available to assist.
