One of the best reasons to learn how to replace a key fob battery is the possibility of getting yourself quickly out of trouble.
A relatively simple battery replacement may mean the difference between continuing driving in a matter of minutes or being left helplessly stranded.
In most cases, you can replace the key fob battery even on a parking lot if necessary, provided you have a spare battery at hand.
Although the battery key fob replacement in this article is done on a Skoda Fabia, you may find it useful for other car types and key fobs.
At the end of this article, there is a YouTube video tutorial, if you’re not in the mood for reading. You can also watch it on our YouTube channel.
WHAT WILL YOU NEED TO REPLACE A KEY FOB BATTERY?
- Smaller flathead screwdriver
This is for dismantling the key and opening the plastic housing containing the battery. The size should fit the little slot on the key fob housing.
- A spare battery
In this key fob, the battery is CR2032, 3 volts.
These are widely available and are, in most cases, not expensive.
This type of battery is more or less standard but best to look up the exact match before you start if you’re changing it on another car. Google it up or look at the driver’s manual.
As a safety precaution, have the spare key fob at hand (if you have one). This way, if something goes wrong, you’ll still be able to drive the car. Also, if the car isn’t already locked, leave the driver’s door open just in case. This way you’ll have access to the passenger cabin if something goes wrong.
- Patience and goodwill
This is important in order to avoid causing any kind of damage. Any use of excessive force due to being nervous may damage plastic clips, the plastic housing, electronics parts, or else.
You’ll see that knowing how to replace a key fob battery is no more complicated than replacing a car fuse for instance. If you want to see how to replace a car fuse, click here for a separate article on that topic.
HOW TO REPLACE A KEY FOB BATTERY? STEP-BY-STEP PROCEDURE
1. Take off the key chain (if there is any) so it doesn’t get in the way
2. Insert the screwdriver in the slot and slowly separate the key part from the plastic housing.
3. Use the screwdriver again to open the plastic housing, Spread the two plastic clips on the sides. The housing separates into two parts: the electronic part(button and transponder) and the other one with the battery housing.
4. Put the tip of the screwdriver under the battery and pop it out. Watch that you don’t break the metal contact on the upper side of the battery. Don’t use too much force so you don’t damage the housing.
5. Insert the new battery-make sure it’s turned on the correct side and sits in properly. You may need to use a bit of force for the battery to fit in. When you hear a „click“, then you know that it’s in place.
6. Assemble the plastic housing. Make sure the parts fit in so you don’t damage anything. When you hear the clips click in, then it’s OK.
7. Press the key fob and if you’ve done everything correctly, you should see the red transponder light blink.
8. Connect the plastic housing with the key part. Again, it should click into place.
9. Go to the car and check if everything works.
Once finished, make sure to check that all the functions on the key fob work properly.
Also, the range for locking and unlocking should be much better.
If any of the functions aren’t working (you have to come close to lock/unlock or the key fob isn’t working at all), you probably did something wrong or perhaps caused damage.
In this case, either repeat the whole procedure or check what’s causing the problem.
HOW TO CHECK A KEY FOB BATTERY?
The best way is to use a multimeter. If the battery is OK, the voltage should be around 3 volts.
Otherwise, something else may be wrong with the key fob.
This is good to determine if the battery is causing the problem or something else.
WHEN TO REPLACE A KEY FOB BATTERY?
You should check or replace the key fob battery when:
- Distance for unlocking shortens (signal range is shorter)
As the battery depletes over time, the range gets shorter and will eventually stop working completely.
- Delayed response
You have to press the buttons on the key fob several times for it to respond. Besides being annoying, a delayed response can damage the buttons because of using excessive force all the time.
- Several clicks are needed from the key fob to respond
Instead of one click, you need to press a couple of times. Because the battery is depleted or nearly depleted it may need some time to gather enough power for the transponder.
HOW LONG DO KEY FOB BATTERIES LAST?
The key fob battery should last from two to four years.
It could be more or less. This depends on the battery quality and did the key fob suffer any kind of past damage (like accidental dropping, contact with water, etc).
In this part, I would like to emphasize the importance of buying a quality battery. Best buy batteries from well-known and renowned manufacturers. The price is not much higher but they last significantly longer.
HOW TO UNLOCK THE CAR WITH A DEAD KEY FOB?
Almost all cars have a fail-safe for unlocking and even starting the car when the key fob battery is depleted.
Every car manufacturer has a procedure or gimmick of their own that sometimes may not be obvious.
So, best look up and learn the exact procedure for your car so you can get yourself out of trouble as soon as possible.
A couple of common ways:
- Using the key for unlocking the door
The classical way but perhaps the most practical and efficient.
There is a lock on the driver’s door which you can simply open with the key fob. This is for fobs that have actual metal keys (key with transponder or a switchblade/flip key).
- A metal key built into the key fob
Some manufacturers build a spare metal key into the key fob itself. It is usually hidden somehow inside the plastic housing. When the battery is depleted, you take out the metal key and unlock the door.
- Variuos smartphone apps
On a lot of modern cars, you can install an app from the manufacturer so they can open the car remotely. A good option, but even better if it’s combined with an actual real spare key.
As you can conclude, learning how to replace a key fob battery is very simple, no more complicated than changing the batteries on your remote control.
Whatever car you drive, you’ll encounter some sort of plastic housing that you have to open up, insert a new battery inside and reassemble the whole thing back together.
Try to always have a spare battery either in the household or in the car. Batteries can stop working at a moment’s notice so having one at hand can be a life-saver.
Don’t let a simple thing like learning how to replace a key fob battery put you in a tight spot, ruin your plans, or even embarrass you.
Written by: Sibin Spasojevic
Former car technician, life-long car and DIY enthusiast, author for Despairrepair.com
HOW TO REPLACE KEY FOB BATTERY-YOUTUBE VIDEO