The fastest place is usually your car dealership or a local locksmith
Your car dealership can replace a key fob battery in minutes, often while you wait. They stock the correct battery type for your vehicle and have the tools to open the fob safely. The cost is typically $10 to $40, though dealerships charge more than independent shops — sometimes $50 or higher depending on the brand.
A local locksmith is usually cheaper and equally fast. Most locksmiths keep common key fob batteries in stock and can swap one out in under five minutes. Call ahead to confirm they have your battery type, since some smaller shops may need to order it.
If you want to avoid a trip, you can buy the battery yourself and replace it at home. The battery itself costs $3 to $8 at any pharmacy, hardware store, or online retailer. The process takes two minutes if you have a flathead screwdriver, though some fobs require a coin or a plastic pry tool instead.
Key Takeaways
- A car dealership will replace your key fob battery while you wait, usually in under ten minutes, for $10 to $50 depending on your vehicle.
- Local locksmiths typically charge $10 to $25 and are faster to reach than dealerships in many areas.
- You can buy the battery yourself for $3 to $8 at a pharmacy or hardware store and replace it at home with a flathead screwdriver.
- The battery type varies by car make and model — common types are CR2032, CR2025, and CR2016, printed on your old battery.
Car dealerships: convenience and certainty
The dealership is the safest choice if you are unsure about your battery type or uncomfortable opening the fob yourself. The service department has your vehicle's specifications on file and will not install the wrong battery. Most dealerships complete the job while you sit in the waiting area.
Dealership prices vary widely. A Honda or Toyota dealership may charge $15 to $25, while luxury brands like BMW or Mercedes can charge $40 to $60. Call the service department before you go — some dealerships require an appointment, and a few charge a diagnostic fee even if you decline the replacement.
Bring your key fob and your vehicle identification number (VIN), which is on your registration or visible on the dashboard. The service advisor will confirm the battery type and give you a price before starting work.
Locksmiths: faster and cheaper in most cases
An independent locksmith usually charges $10 to $25 and can often fit you in same-day without an appointment. Search "locksmith near me" or check Google Maps for shops with recent reviews. Call first — ask if they stock your battery type and what they charge.
Locksmiths typically keep CR2032, CR2025, and CR2016 batteries in stock, which cover most cars made in the last 15 years. If your fob uses an unusual battery, the locksmith may need to order it, which adds a day or two. Some locksmiths also offer mobile service and will come to your home or workplace.
Bring your key fob and be ready to describe your car's make and model. The locksmith will confirm the battery type by looking at your old one or checking their reference guide.
Pharmacy and hardware stores: buy the battery and do it yourself
CVS, Walgreens, Rite Aid, and most local pharmacies stock key fob batteries in the watch and battery section. Home Depot, Lowe's, and Ace Hardware carry them too. The battery costs $3 to $8, and you can replace it yourself in two minutes.
First, find out what battery your fob needs. Look at your old battery — the type is printed on it (CR2032 is the most common). If you cannot open the fob, call your dealership or a locksmith and ask what type they recommend for your car.
To replace it yourself, locate the seam on the edge of the fob. Use a flathead screwdriver, a coin, or a plastic pry tool to gently separate the two halves. Slide out the old battery, note which side was facing up, and slide the new one in the same way. Snap the fob back together and test it.
Online retailers: cheapest option if you have time
Amazon, eBay, and Walmart sell key fob batteries for $2 to $5 per battery, often in packs of two or four. Shipping takes two to seven days depending on your location and whether you have Prime. This option makes sense only if you are not in a hurry or want to stock extra batteries.
Order by battery type, not by car model — the same CR2032 battery works in thousands of different fobs. Read the product reviews to confirm the battery works in key fobs, since some listings are for watches or other devices.
What to do if your fob is stuck or damaged
If the fob will not open or the battery compartment is corroded, do not force it. A locksmith or dealership can open it without breaking the plastic. Corrosion usually means water got inside — the battery may work temporarily, but the fob will likely fail again soon. Ask the technician whether the fob is worth repairing or whether a replacement is cheaper.
Some newer cars use fobs that cannot be opened by the owner. Tesla, some Hyundai models, and certain luxury vehicles require dealership service. Check your owner's manual or call the dealership to confirm before you try to open yours.
Cost comparison table
| Option | Cost | Time to completion | Best for |
|---|---|---|---|
| Car dealership | $10–$60 | Same day, usually under 10 minutes | Luxury cars, unusual battery types, peace of mind |
| Local locksmith | $10–$25 | Same day, usually under 10 minutes | Budget-conscious, no appointment needed |
| DIY at pharmacy or hardware store | $3–$8 | when ready (you do it at home) | Common battery types, comfortable with tools |
| Online retailer | $2–$5 | 2–7 days shipping | Buying in bulk, no time pressure |
Frequently Asked Questions
How do I know what battery type my key fob needs?
Look at your old battery — the type is printed on it. Common types are CR2032, CR2025, and CR2016. If you cannot open the fob, call your car dealership with your vehicle's make and model, and they will tell you the type over the phone.
Can I replace the battery myself if I have never done it before?
Yes. The process is straightforward: find the seam on the edge of the fob, use a flathead screwdriver or coin to pry it open, slide out the old battery, and slide in the new one the same way. If the fob is stuck or you are uncomfortable, a locksmith or dealership can do it for $10 to $25.
What if my key fob still does not work after I replace the battery?
The fob may have water damage or a broken button contact. Try cleaning the battery contacts with a dry cloth before reassembling. If it still does not work, take it to a locksmith or dealership — they can diagnose whether it is worth repairing or whether you need a replacement fob.
Is it cheaper to replace the whole key fob or just the battery?
Replacing the battery is much cheaper — $3 to $25 depending on where you go. A replacement fob costs $100 to $400 depending on your car. Always try a new battery first.
How long does a key fob battery usually last?
Most key fob batteries last three to four years with normal use. If you use your fob frequently, the battery may last only two years. The battery will gradually weaken before it dies — you may notice the fob working only from closer distances.