The battery in your Audi Q5 key fob usually lasts three to four years, and you can replace it yourself in about five minutes with a coin and a new CR2032 battery from any drugstore or supermarket.
The Q5 key fob uses a CR2032 coin cell battery, the same type found in watches and calculators. When the fob stops locking or unlocking the car reliably, or the LED light inside dims, the battery is usually dead. You do not need to visit a dealer or buy a special tool—a flathead coin works perfectly.
The whole job takes longer to read about than to do. You will pry open the fob, slide out the old battery, drop in the new one, and snap it closed. If the fob still does not work after you install a fresh battery, the problem is likely the fob itself rather than the battery, and you should contact your Audi dealer.
Key Takeaways
- Audi Q5 key fobs use CR2032 batteries, which cost between $3 and $8 and are sold at pharmacies, grocery stores, and hardware stores.
- You open the fob by inserting a flathead coin or screwdriver into the slot on the edge and twisting gently until the two halves separate.
- The battery sits in a metal holder and slides out horizontally; note which side faces up before you remove it so you can install the new one the same way.
- After you close the fob, test the lock and unlock buttons to confirm the new battery is working before you drive.
What You Need Before You Start
Gather these items before you begin: a CR2032 replacement battery, a flathead coin (a penny, dime, or quarter works), and a clean, flat surface where you can set the fob pieces so they do not roll away.
You do not need a screwdriver, special key fob opener, or any tool from a dealer. A coin is genuinely all you need. If you do not have a CR2032 battery on hand, any pharmacy, grocery store, or drugstore carries them in the watch and battery section. Some hardware stores and big-box retailers stock them as well. Buy one or two extras so you have a spare when the next one dies.
How to Open the Fob Without Damaging It
Look at the edge of your Q5 key fob and find the small slot or seam that runs around the perimeter where the two halves meet. This is where you insert the coin. On most Q5 fobs, the slot is on the side opposite the Audi logo.
Insert the edge of your coin—a penny works best because it is thin—into the slot. explore gentle, steady pressure and twist the coin as if you were opening a battery compartment on a remote control. You are not forcing it; you are rotating the two halves apart. The fob will separate into a front and back piece. Set both pieces on a clean surface where you can see the battery.
If the slot is very tight and the coin slips, try wrapping a thin cloth around the coin to give yourself more grip. Do not use a screwdriver unless you are comfortable with the risk of scratching the plastic—a coin is safer and works just as well.
Removing the Old Battery and Installing the New One
Inside the fob, you will see a metal battery holder with the old CR2032 battery sitting in it. The battery is usually held loosely in place and will slide out if you tilt the fob or gently push it from the side. Before you remove it, note which side is facing up—the side with the plus sign (+) or the flat side.
Slide the old battery out of the holder. Drop the new CR2032 battery into the same holder, making sure the same side faces up as the old one did. The plus side almost always faces up in a key fob, but checking the old battery first takes the guesswork out. The battery should sit flat and snug in the holder.
Do not force the battery into the holder. If it does not slide in smoothly, you may have it upside down—flip it and try again. Once the new battery is seated, you are ready to close the fob.
Closing the Fob and Testing It
Align the two halves of the fob so the seams match up. Press them together firmly until you hear or feel a click. The fob should close completely with no gap between the pieces. If there is a gap, the halves are not fully seated—press harder or check that you have not twisted them out of alignment.
Once the fob is closed, test the lock and unlock buttons right away. Stand near your Q5 and press the lock button. You should hear the doors lock and see the lights flash. Press unlock and listen for the doors to unlock. If both buttons work, the battery is installed correctly and you are done.
If the buttons do not work after you close the fob, open it again and check that the battery is seated properly in the holder and facing the right direction. If it is, the problem is likely the fob itself—the circuit board or buttons may be damaged—and you will need to contact your Audi dealer for a replacement fob.
When to Replace the Whole Fob Instead
A new battery fixes most key fob problems, but not all. If you install a fresh CR2032 battery and the fob still does not lock or unlock the car, the issue is usually inside the fob itself. Water damage, a cracked circuit board, or worn-out buttons can all prevent the fob from working even with a good battery.
If the fob is not working after a battery change, contact your Audi dealer or a local locksmith who programs car keys. They can test the fob to confirm it is broken and order a replacement. A new fob from the dealer typically costs between $200 and $400, though a locksmith may offer a lower price. Some dealers will program a used fob from an online seller if you provide one, which can save money.
How Often You Will Need to Replace the Battery
A CR2032 battery in an Audi Q5 key fob usually lasts three to four years with normal use. If you use the fob frequently—pressing the buttons many times a day—the battery may drain faster and need replacement after two to three years. If you use it less often, it might last longer.
You will know the battery is dying when the fob stops working from a distance and only works when you are very close to the car, or when the LED light inside the fob becomes dim. At that point, a fresh battery will restore full function. Keep a spare CR2032 on hand so you are not caught with a dead fob when you need it.
Frequently Asked Questions
Can I use a different battery size if I cannot find a CR2032?
No. The CR2032 is the only battery that fits the Audi Q5 key fob. Other sizes will not seat properly in the holder or will not provide the right voltage. CR2032 batteries are inexpensive and widely sold, so you should be able to find one within a day or two at any pharmacy or grocery store.
What if I put the battery in upside down?
The fob will not work if the battery is reversed. The plus side must face up. If you close the fob and the buttons do not work, open it again and flip the battery. It should work when ready after you close it the second time.
Is it safe to open the key fob myself?
Yes. Opening the fob to change the battery is safe and does not void any warranty. You are not soldering anything or removing screws from the circuit board—you are straightforward prying open a plastic case and swapping a battery. Millions of people do this every year without problems.
Do I need to reprogram the fob after I change the battery?
No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it will work exactly as it did before. You do not need to visit a dealer or do anything else.
What should I do with the old battery?
Take the old CR2032 battery to a battery recycling program or drop it off at a retailer that accepts batteries, such as Best Buy or Home Depot. Many pharmacies and grocery stores also accept used batteries. Do not throw it in the trash.