Car keys used to be just keys—pieces of metal that you insert into keyholes to lock or unlock your doors or start your ignition. However, most car keys nowadays come in the form of key fobs. Key fobs or “Frequency Operated Buttons” are digital transmitters that allow keyless entry systems in most modern cars.
The most common types of modern key fobs are a regular Passive Keyless Entry (PKE) and Smart Key. Passive keyless entry usually still comes with an emergency key inside the fob. This is so that you can still unlock the driver’s door when the fob battery dies or when it malfunctions. A smart key fob takes car technology up a notch by having a receiver that your car is able to automatically recognize. With most smart keys, you won’t have to press any button to unlock your car doors or even to start your ignition—your car senses your proximity and radio pulse travels through the built-in antennas of your car, doing these things automatically for you.
Just like any battery-operated device, car key fobs also require battery changes from time to time. On the average, a regular keyless entry fob can last from 4 to 6 years while a smart key fob’s battery will last 2 to 3 years. Are you prepared to change your own batteries when the inevitable happens?
Step-By-Step Instructions for Replacing your Key Fob Battery
What you’ll need:
- 3-Volt batteries: CR2016, CR2025, CR2032, CR2450—depending on what your fob uses; these are the most common types.
- Flat blade screwdriver
- Soldering iron (optional)
Step 1: Check if your fob has an emergency key slotted in. If so, remove that first.
Step 2: Use your flathead screwdriver to pry apart your key fob. Look for a notch to insert the screwdriver and carefully work your way around the edges until the clips are released.
Step 3: Check the type of battery you need to ensure sure you’ve got the correct new one. You can also see this in your owner’s manual. It’s advisable to keep a few spares in case of emergency.
Step 4: Pop out the old battery and put in the replacement. You can use the flathead screwdriver if the battery does not pop out by using just your fingers.
Step 5: Attach the two parts of the fob back together securely and you’ll be good to go!
Desoldering your Car Key Fob for Battery Replacement
For some smart key fobs, the only way to replace a battery is to desolder the battery compartment from the circuit board. To do this, apply heat to the existing solder, use a desoldering pump to suck the molten solder, and then carefully remove the battery compartment, pop out the old batter and replace it with a new one.
If you choose to solder the components back together yourself, keep in mind that you must exercise caution in using the iron, as electronics can’t take too much heat—leaving the iron on for too long can damage the board. You must also ensure that you are using a soldering iron that’s intended for electronics and not for plumbing.
If you’re not confident about soldering your key fob on your own, the next best step is to call a locksmith that can help you. Professional auto-locksmiths at Easy Keys can provide rapid service 24/7. Locksmiths can help fix even the smallest parts of your keys to ensure that these don’t cause bigger problems later on.