How to Replace Your Car Key Battery: A Step-by-Step Guide

Is your car key fob acting up? Perhaps it's only working intermittently, or you have to be right next to your car for it to function. Before you spend money on a costly key fob replacement, the solution might be as simple as a new battery. This guide will walk you through how to replace your car key battery quickly, easily, and affordably, saving you time and money.

Why is My Car Key Battery Not Working?

Car key batteries typically last a few years, but they don't last forever. Here are common signs that your car key battery might be dying:

• Inconsistent Functionality: The key fob only unlocks your car doors sometimes.

• Reduced Range: You need to be closer to your car than usual for the remote to work.

• Dim or No LED Light: Many key fobs have an LED light that flashes when you press a button. If this light is dim or doesn't turn on at all, it’s likely time for a new battery.

• Multiple Presses Required: You have to press the buttons multiple times to get the car to respond.

• No Signal: The key fob does not work at all.

It's important to note that even with a dead battery, you can still manually enter and start your car. The battery only powers the remote locking/unlocking system, not the immobilizer, which uses a passive transponder chip.

Is it Definitely the Battery?

Before replacing your battery, you should rule out other potential issues.

• Check Manual Locks: Verify the manual locks on the car work. If they don’t, the issue might be with the car's locking mechanism.

• Try a Spare Key: If you have another key fob, try using it. If the second key works, it’s very likely that the first key's battery is the problem.

• Check Security Settings: Security conditions may have disabled remote entry, in which case reprogramming may be required.

Tools You'll Need

The process is generally simple and doesn't require specialized tools. Here’s what you might need:

• A new car key battery (make sure you know the correct model).

• A small flathead screwdriver or a butter knife.

• Your fingernails (in some cases, you may be able to open the fob without any tools).

• A small amount of isopropyl alcohol (optional, for cleaning the battery).

Step-by-Step Guide to Replacing Your Car Key Battery

1. Open the Key Fob:

• Most fobs can be opened by gently prying them apart with your fingernails.

• If the fob does not open easily, look for a small slot or opening where you can insert a flathead screwdriver or a butter knife.

• Apply gentle, even pressure from several locations around the fob to avoid damage.

• Some key fobs have a small screw that you will need to remove before prying it open.

• Some fobs have a valet key that should be removed before attempting to open the fob.

• If you have a key with a metal insert, remove that first.

• You may need to use a side-to-side twisting motion to pry the key open.

2. Identify the Battery Type:

• Once the fob is open, you'll see the battery. Note the battery code, usually a two-letter prefix followed by numbers (e.g., CR2032).

• You might need to lift the circuit board to see the battery code.

• Important: Your key will only work with the same battery type.

3. Remove the Old Battery:

• Use your flat object to gently remove the old battery.

• Take note of the polarity (+ and -) of the old battery before removing it.

4. Clean the Battery Contacts (Optional):

• Use a small amount of isopropyl alcohol and a cotton swab to clean the contact surfaces of the battery to ensure better conductivity.

• This step is not essential, but it can improve the battery's performance.

5. Insert the New Battery

• Place the new battery in the same way as the old battery, paying attention to the polarity.

6. Close the Fob:

• Carefully clip the two halves of the fob back together.

• Apply pressure to each corner until it snaps back into place.

Which Battery Do I Need?

Car key fobs most often use lithium coin batteries, like the CR2032, CR2025, and CR2016. Here are some of the batteries that we stock, that are often used in car key fobs:

• CR2032: This is a very common battery for car key fobs. Consider the Panasonic CR2032 Battery or the Energizer CR2032 Batteries.

• CR2025: Also commonly used, you could use the Energizer CR2025 Battery or the Panasonic CR2025 Battery.

• CR2016: A less common size, but you might need a Panasonic CR2016 3V Battery.

• LR44: This alkaline button cell battery can also be used in car key fobs. You may be able to use the Duracell LR44 Watch battery.

Where to Buy Car Key Batteries

You can purchase car key batteries at most supermarkets or online. However, for the best quality and reliability, it’s worth considering reputable suppliers like TradeNRG UK.

Why Buy From TradeNRG UK?

• Quality: We stock batteries from trusted brands like Panasonic, Energizer and Duracell.

• Variety: We offer a wide range of battery types to suit various car key fobs.

• Competitive Prices: We have great prices on all our products, and you can save even more money by buying a bulk pack to have on hand.

Troubleshooting: What If It Still Doesn’t Work?

If your key fob isn’t working after replacing the battery, consider the following:

• Incorrect Battery Type: Double-check you’ve used the correct model number.

• Battery Position: Make sure the battery is positioned correctly with the right polarity (+ and -).

• Reprogramming: Some fobs need reprogramming after a battery change. Check your car’s manual or contact an auto locksmith.

• Damaged Fob: If the fob still isn’t working, it might be damaged. Contact a specialist for repair or replacement.

Additional Tips for Car Key Battery Replacement

• Buy in Bulk: Buying a bulk pack can save you money, as you'll have replacement batteries on hand for when you need them.

• Don't Leave the Battery Out: Leaving the battery out of the fob for too long can cause the fob to stop communicating with the car and require reprogramming.

• Avoid Counterfeit Batteries: Be cautious of cheap, counterfeit batteries, especially when purchasing online. These may not last very long. If buying online, make sure that the seller is reputable.

• Use Name Brand Batteries: Name-brand batteries like Energizer and Panasonic tend to last longer than generic brands.

• Don't Use More Powerful Batteries: Using a more powerful battery will not improve the battery life of your key fob and can cause damage.

• Recycle Old Batteries: Dispose of your old batteries at a specialist recycling point.

When to Seek Professional Help

While replacing a car key battery is usually straightforward, you might need help from an auto locksmith if:

• You cannot open the key fob.

• You're unsure about the battery type.

• The key fob is damaged.

• The key fob requires reprogramming.

Conclusion

Replacing your car key battery is a simple, cost-effective way to resolve many common car key issues. By following this guide and purchasing high-quality batteries from TradeNRG UK, you can ensure your key fob works reliably for years to come.

Don't let a dead key fob battery inconvenience you. Visit TradeNRG UK today to browse our selection of car key batteries and keep your car access smooth and stress-free!.

Frequently Asked Questions (FAQs)

1. How long do car key fob batteries typically last?
   

• Car key fob batteries typically last for 3-4 years. However, this can vary based on usage and battery quality.

2. What are the most common types of batteries used in car key fobs?
   

• The most common types are CR2032, CR2025, and CR2016 lithium coin batteries. Some fobs may also use LR44 alkaline button cell batteries.

3. Can I use a different battery if I don’t have the exact one specified?
   

• No, it’s important to use the exact battery type specified for your key fob. Using the wrong battery can damage the fob or cause it not to work.

4. Do I need any special tools to replace my car key battery?
   

• Generally, you’ll only need a small flathead screwdriver or your fingernails to open the fob. Some fobs may require a small screwdriver to remove a screw.

5. Will replacing my car key battery affect my car's immobilizer system?
   

• No, the battery only powers the remote locking/unlocking system. The immobilizer uses a passive transponder chip that doesn't require a battery.

6. What if my key fob still doesn’t work after replacing the battery?
   

• If your key fob still doesn't work, check that you used the correct battery type and that it's installed with the correct polarity. It may also need to be reprogrammed, or the fob may be damaged.

7. Where is the best place to buy car key batteries?
   

• You can buy car key batteries at most supermarkets or online. For the best quality and reliability, it’s recommended to buy from a reputable supplier like TradeNRG UK.

8. Is it okay to touch the battery with my bare hands?
   

• It is best to avoid touching the battery with your bare hands as the oils on your skin can affect the conductivity. It's better to use gloves or a cloth when handling the battery.

9. Can I use a more powerful battery to make my key fob last longer?
   

• No, using a more powerful battery won't extend the life of your fob and can potentially damage it. Always use the specified battery type.

10. How should I dispose of my old car key battery?
    

• Old car key batteries should be taken to a specialist recycling point. Do not discard them in household waste.