The battery in a car remote, or key fob, powers the system that unlocks doors, starts the engine, and transmits signals to the vehicle. Because remotes vary by model and year, identifying the correct battery size is essential for reliable performance. This guide covers common battery sizes, how to check yours, and step-by-step replacement tips to ensure your car remote functions correctly.
Common Car Remote Battery Sizes
Car remotes typically use small, coin-shaped batteries or small rectangular batteries. The most frequent sizes include CR2032, CR2025, CR1632, and the A23 (also called 23A) battery. Some luxury or newer vehicles may use different models. Identifying the exact size usually involves opening the fob or checking the owner’s manual.
How To Identify The Right Battery For Your Car Remote
There are several reliable methods to confirm the correct battery size. Check the owner’s manual or the inside of the fob for the model number printed near the battery compartment. If the manual is unavailable, locate the current battery and read the imprint on its surface, which often shows the size. Compare dimensions—CR2032 is 20 mm in diameter and 3.2 mm thick, CR2025 is 20 mm by 2.5 mm, and CR1632 is 16 mm by 3.2 mm. For A23, dimensions are approximately 10.5 mm by 28 mm.
Step-By-Step Battery Replacement
Replacing a car remote battery is generally straightforward. The steps below apply to most fobs, but adapt as needed for your specific model.
- Identify and purchase the correct size from the list above or your vehicle manual.
- Open the fob using a small flathead screwdriver, a coin, or a plastic prying tool. Be gentle to avoid damage.
- Remove old battery noting orientation (which side faces up).
- Insert new battery with the correct polarity. The positive (+) side usually faces up.
- Reassemble the fob and test the buttons from a short distance.
If your remote has a spring or gasket, ensure it sits correctly before closing. Some models require a tiny Phillips or Torx screwdriver; others can be opened with a coin. For sealed or water-resistant designs, avoid forcing the case apart and consult the manual or dealer if in doubt.
Testing And Troubleshooting After Replacement
After replacing the battery, test all functions: lock, unlock, trunk release, and remote start if equipped. If signals are weak or absent, try these steps:
- Ensure battery orientation is correct.
- Check battery contact points for corrosion or dirt; clean gently with a dry cloth.
- Test from a shorter distance to rule out distance limitations.
- Replace the battery with a fresh one if the old battery was near its end of life.
When To Replace The Remote Itself
Replacing the battery usually restores function. However, persistent issues may indicate a faulty remote or radio receiver problems in the vehicle. If the remote stops working after battery replacement or only works intermittently, consider these steps:
- Reprogramming or re-syncing the remote with the car, as described in the owner’s manual or by a dealer.
- Trying a spare remote to determine if the issue is specific to one fob.
- Consulting a dealership or automotive locksmith for reprogramming services or remote replacement if needed.
Tips To Extend Remote Battery Life
Smart maintenance can extend the life of your car remote battery. Avoid exposing the fob to extreme temperatures or moisture, which can drain power or damage components. If your vehicle offers remote start or keyless entry, use these features sparingly in extreme weather to conserve battery life. Regularly check the fob for visible wear and clean contacts to ensure reliable signal transmission.
Common Questions About Car Remote Batteries
Q: Can I use a different brand or non-OEM battery? A: In most cases, yes, as long as the size and voltage match the original. Stick to high-quality brands to avoid leakage or corrosion.
Q: How long do car remote batteries last? A: Typical life ranges from 1 to 3 years, depending on usage, remote features, and environment.
Q: Is it safe to dispose of old batteries with household waste? A: No. Recycle car batteries at approved facilities or retailers that offer battery recycling programs to prevent environmental harm.
Battery Size Reference Table
| Battery Size | Typical Use | Approximate Dimensions |
|---|---|---|
| CR2032 | Common high-drain remotes | 20 mm x 3.2 mm |
| CR2025 | Standard remotes with compact design | 20 mm x 2.5 mm |
| CR1632 | Compact fobs or smart keys | 16 mm x 3.2 mm |
| A23 (23A) | Long-nose remotes, vehicle fobs | ~10.5 mm x 28 mm |
Keeping the correct battery size on hand and understanding how to replace it can save time and reduce frustration when a remote stops working. By consulting the vehicle manual, verifying the current battery, and following proper replacement steps, most car remotes regain full functionality quickly. Regular maintenance and cautious handling further ensure reliable access to the vehicle when needed.