Key fobs are essential for modern vehicle convenience, allowing us to lock, unlock, and even start our cars remotely. These handy devices rely on small batteries to function, and understanding what size battery your key fob takes is crucial for ensuring you’re never caught off guard with a dead fob. Like any battery, key fob batteries eventually need replacing. Knowing the signs of a weakening battery and how to find the correct replacement size will save you time and frustration.
Why Knowing Your Key Fob Battery Size Matters
Using the correct battery size for your key fob is not just about convenience; it’s about ensuring proper functionality and preventing potential damage. Key fobs are designed to operate with a specific voltage and current, which is determined by the battery type they use. Inserting the wrong size battery can lead to several issues:
- Poor Performance: An incorrect battery might not supply the necessary power, leading to reduced signal range, inconsistent button response, or complete failure of the key fob.
- Damage to the Fob: In some cases, a battery that is too large or has the wrong voltage could damage the internal circuitry of your key fob, requiring costly repairs or replacement of the entire fob.
- Battery Leakage: An improperly fitted battery might be more prone to leakage, which can corrode the key fob’s internal components and render it useless.
Therefore, taking the time to identify the correct battery size is a small but important step in maintaining your vehicle’s key fob and ensuring its reliability.
How to Find Out What Size Battery Your Key Fob Takes
Determining the correct battery size for your key fob is usually a straightforward process. Here are several reliable methods:
1. Check the Key Fob Itself
The most direct way to find your key fob battery size is by examining the key fob itself. Many key fobs have the battery size printed directly on the casing, often on the back or inside the battery compartment.
- Look for Markings: Carefully inspect the surface of your key fob. You might find a series of numbers and letters, such as “CR2032,” “CR2025,” or “CR1632.” These codes indicate the battery type and size.
- Open the Battery Compartment: If you don’t see markings on the exterior, you may need to open the battery compartment. Refer to your owner’s manual or search online for instructions specific to your key fob model. Once open, the battery size is often printed on the battery itself or inside the compartment.
2. Consult Your Vehicle’s Owner’s Manual
Your vehicle’s owner’s manual is a treasure trove of information, including specifications for your key fob.
- Locate the Key Fob Section: Look in the index or table of contents for sections related to “key fob,” “remote control,” or “keyless entry.”
- Battery Information: Within this section, you should find details about the type of battery used in your key fob, including the size and specifications.
3. Use Online Key Fob Battery Finder Tools
For quick and convenient identification, online key fob battery finder tools can be very helpful.
- Key Fob Battery Finder on Keyfobx.com: Websites like Keyfobx.com often provide tools where you can enter your vehicle’s make, model, and year to find the correct battery size for your key fob.
- Automotive Parts Websites: Many auto parts retailers also have battery finder tools on their websites that can help you identify the right battery based on your vehicle information.
4. Check Battery Retailer Websites
Battery manufacturer and retailer websites are excellent resources for battery information.
- Battery Size Charts: Reputable battery brands like Duracell or Energizer often have online battery size charts or finders. You can typically search by battery type (e.g., coin cell, lithium) or browse through their catalogs to find the sizes they offer.
- Vehicle-Specific Lookups: Some battery retailers allow you to search for batteries compatible with your specific vehicle make and model, which can include key fob batteries.
Common Key Fob Battery Sizes
Key fobs typically use coin cell batteries, also known as button cell batteries. These small, round batteries come in various sizes and chemistries. Here are some of the most common key fob battery sizes:
- CR2032: This is one of the most frequently used key fob battery sizes. It is a 3V lithium coin cell battery, 20mm in diameter and 3.2mm thick. It offers a good balance of power and longevity, making it suitable for many key fob applications.
- CR2025: Similar to CR2032 but slightly thinner (2.5mm thickness), the CR2025 is another common 3V lithium coin cell battery. It may be used in slimmer key fobs or when a slightly lower profile battery is needed.
- CR1632: This 3V lithium coin cell battery is smaller in diameter (16mm) and thickness (3.2mm) compared to the CR20 series. It’s often found in more compact key fobs.
- CR1620: Thinner than CR1632 (2.0mm thickness) and with the same 16mm diameter, the CR1620 is another 3V option for smaller key fobs.
- CR2450: A larger 3V lithium coin cell, the CR2450 is 24.5mm in diameter and 5.0mm thick. It offers higher capacity for key fobs that require more power or longer battery life.
While these are common sizes, your key fob might use a different battery type. Always verify the correct size before purchasing a replacement.
Signs Your Key Fob Battery Needs Replacing
Recognizing the signs of a low key fob battery can help you replace it before it completely dies, potentially saving you from inconvenience. Here are common indicators:
1. Decreased Signal Range
One of the first and most noticeable signs is a reduction in the key fob’s operating range.
- Shorter Distance: You may find that you need to be much closer to your car for the key fob to lock or unlock the doors. Where you used to be able to activate the car from a distance, you now need to be right next to it.
2. Inconsistent Clicks
A weakening battery can lead to inconsistent button responses.
- Multiple Presses Required: You might need to press the buttons multiple times for the car to respond. Sometimes it works on the first try, other times it takes several attempts.
3. Delayed Unlocking or Locking
Even if the range seems okay and clicks are consistent, delays in action can signal a low battery.
- Slow Response: You press a button, and there’s a noticeable delay – several seconds – before the car locks or unlocks, or performs another function.
4. Dashboard Warning Light
Some newer vehicles are equipped with systems that monitor key fob battery health.
- Key Fob Battery Warning: Your car’s dashboard might display a warning light or message specifically indicating a low key fob battery. Refer to your owner’s manual to understand what specific warning lights mean.
5. Key Fob Not Working at All
In the most extreme case, a dead battery will result in complete key fob failure.
- No Response: The key fob becomes completely unresponsive. Buttons do nothing, and the car doesn’t react to any commands.
Note: Even with a dead key fob battery, you can still access your vehicle using the mechanical key hidden inside the fob. Refer to your owner’s manual for instructions on accessing the mechanical key.
Step-by-Step Guide to Replacing Your Key Fob Battery
Replacing a key fob battery is a simple DIY task for most vehicles. Here’s a general step-by-step guide:
- Gather Your Tools: You’ll typically need a small flathead screwdriver or a similar tool to open the key fob casing. Have your new battery of the correct size ready.
- Find the Battery Size: Before you begin, double-check that you have the correct replacement battery size using one of the methods described earlier.
- Open the Key Fob Casing: Examine your key fob to find the opening point. Many fobs have a small notch or seam. Gently insert the flathead screwdriver into this opening and twist or pry to separate the two halves of the casing. Some key fobs might have screws that need to be removed first.
- Remove the Old Battery: Once the casing is open, you’ll see the battery. Note the orientation of the old battery (the positive (+) and negative (-) sides). Gently pry out the old battery.
- Insert the New Battery: Place the new battery into the compartment, ensuring it’s in the correct orientation (match the +/- signs).
- Close the Key Fob Casing: Carefully snap the two halves of the key fob casing back together until they are securely closed. If there were screws, replace and tighten them.
- Test Your Key Fob: Press the buttons on your key fob to test if it’s working correctly. Lock and unlock your car, and test other functions like remote start or panic button to ensure the new battery is functioning as expected.
Tips for Key Fob Battery Maintenance and Longevity
While key fob batteries are designed to last, here are a few tips to potentially extend their lifespan:
- Avoid Extreme Temperatures: Extreme heat or cold can impact battery performance and longevity. Avoid leaving your key fob in direct sunlight or freezing temperatures for extended periods.
- Store Spare Batteries Properly: If you keep spare batteries, store them in a cool, dry place away from metal objects to prevent short circuits.
- Gentle Use: While key fobs are relatively durable, avoid excessive dropping or rough handling, which could potentially damage the battery or internal components.
Conclusion
Knowing what size battery your key fob takes and understanding the signs of a low battery are essential for every car owner. By taking a few minutes to identify the correct battery and learning how to replace it, you can ensure your key fob remains a reliable tool for accessing and securing your vehicle. For more information and tools to help you find the right key fob battery, visit keyfobx.com today!
