Introduction to Measuring Car Key Fob Battery Voltage
In this guide, I’ll show you how to easily measure the voltage of a coin battery, like the ones found in car key fobs, using a basic multimeter. This method helps determine whether your battery still has sufficient voltage or if it’s time for a replacement.
- Pack of 2 batteries
- Lithium coin batteries for watches and electronic devices
- Has a power of 3 volts
Setting Up Your Multimeter
The first step involves setting up your multimeter correctly. I have a standard multimeter and have set it to the battery setting. For this task, you should set it to the 9V setting, even though the batteries are 3V. This ensures an accurate reading.
Understanding Battery Types
It’s essential to understand the types of batteries used in car key fobs. For instance, I have a CR1616 battery, which is known to be dead. The numbers in the battery name indicate the dimensions: the first two digits represent the diameter, and the last two represent the thickness.
Testing a Dead Battery
To test the battery, you need to hold it securely. In this case, I use a small clamp. Place the positive (red) probe on the top and the negative (black) probe on the bottom. If the battery is dead, the multimeter will show no voltage.
Testing a New Battery
Next, let’s test a new battery, a CR2450. This one has a larger diameter and is thicker than the CR1616. Place the positive probe on the side with the lettering and the negative probe on the rippled side. A good battery should show a voltage around 3V.
For example, this new CR2450 shows 3.25V, indicating it has a high voltage and will last for a while.
- IN THE BOX: 6-pack of CR1616 3-volt lithium coin cell replacement batteries for small electronic devices
- DEVICE COMPATIBLE: Ideal for watches, calculators, games, medical devices, and more
- LONG LASTING: Long-lasting, reliable battery life; performs in extreme temperatures
When to Replace Your Battery
If a battery shows a voltage below 2.9V, it is likely time for a replacement. For instance, another battery I tested showed 2.79V, suggesting it needs to be replaced soon.
Testing Another New Battery
Let’s test another new battery, a CR1632 from Amazon Basics. Again, place the positive probe on the side with the lettering and the negative probe on the rippled side. The multimeter shows 3.2V, indicating it’s a good battery.
Conclusion
Measuring the voltage of your car key fob battery with a multimeter is a straightforward process. Ensure you set your multimeter correctly and test both the positive and negative sides of the battery. If your battery shows a voltage around 3V, it’s in good condition. If it’s below 2.9V, consider replacing it.
If you still have issues with your car key fob despite having a good battery, the problem might lie elsewhere in the fob.
Frequently Asked Questions (FAQ)
Why should I measure my car key fob battery?
Measuring your car key fob battery ensures it has enough voltage to function correctly. It helps you decide when to replace the battery.
What multimeter setting should I use?
Set your multimeter to the battery setting and then to the 9V setting for accurate readings of a 3V battery.
How do I know if my battery is dead?
If the multimeter shows no voltage or a voltage below 2.9V, the battery is likely dead or needs replacement.
What do the numbers on the battery mean?
The first two digits represent the diameter, and the last two represent the thickness of the battery.
Where should I place the multimeter probes?
Place the positive (red) probe on the side with the lettering and the negative (black) probe on the rippled side.
What voltage indicates a good battery?
A good battery should show a voltage around 3V. If it’s significantly lower, consider replacing it.
What if the battery shows 3V but the fob doesn’t work?
If your battery shows 3V but the key fob still doesn’t work, the issue might be with the fob itself.
- 3V, 280mAH, 2 pack
- D:24.5mm, H:3.0mm
Additional Tips
Using a multimeter is an easy and effective way to check your car key fob battery. Regular checks can prevent unexpected failures. Always ensure your multimeter is correctly set to avoid inaccurate readings.
For reliable multimeters, I recommend those from Klein Tools. They are accurate and user-friendly. A good multimeter is a valuable tool for various household tasks.
By following these steps, you can ensure your car key fob battery is always in good condition. This simple maintenance task can save you from the inconvenience of a non-functional key fob.