The fastest places to buy a key fob battery
You can buy a key fob battery at any pharmacy, big-box retailer, or auto parts store — most stock them in the checkout aisle or electronics section. Walgreens, CVS, Walmart, Target, Best Buy, AutoZone, O'Reilly Auto Parts, and Advance Auto Parts all carry common sizes like CR2032, CR2025, and CR2016. Many of these stores will also install the battery for free or for a small fee if you ask at the counter.
If you need the battery today, a pharmacy or grocery store is your fastest option because they are usually closer than a specialty auto shop. If you want the lowest price and do not mind waiting a few days, Amazon and other online retailers often sell batteries in bulk packs for less per unit than a single battery costs in a store.
Your car dealership can also replace the battery, but they typically charge more than a retail store and may require an appointment. Call ahead to confirm they have your specific fob model in stock before you drive there.
Key Takeaways
- Pharmacies, grocery stores, and big-box retailers stock key fob batteries in their checkout or electronics aisles and usually have them in stock the same day.
- Auto parts stores like AutoZone and O'Reilly carry a wider selection of battery sizes and often install them free when you buy from them.
- Many retailers will install the battery for you at no charge, so ask before you leave the store.
- Online retailers sell batteries cheaper per unit if you buy in bulk, but you will need to wait several days for delivery.
- Your car dealership can replace the battery but usually charges more than retail stores and may require an appointment.
How to identify which battery size your fob needs
The battery size is printed on the back of your key fob or inside the battery compartment itself. Look for a code like CR2032, CR2025, CR2016, or LR44 — these are the most common sizes. If you cannot find the code on the fob, check your car's owner manual or search online for your specific car make, model, and year plus "key fob battery."
When you go to the store, bring the old battery with you if you have already removed it. The staff can match it to the right replacement in seconds. If you have not opened the fob yet, take a photo of the battery code and show it to the store employee — they will point you to the right shelf.
What to expect when you buy in different places
Pharmacies and grocery stores (Walgreens, CVS, Rite Aid, Kroger, Safeway) stock the most common sizes like CR2032 in the checkout aisle or near the registers. Prices range from $3 to $8 per battery. Most will not install it for you, but the process takes less than a minute at home.
Big-box retailers (Walmart, Target, Best Buy) carry batteries in the electronics or automotive section. Prices are similar to pharmacies, and some locations offer free installation if you ask. Call ahead to confirm your store offers this service.
Auto parts stores (AutoZone, O'Reilly, Advance Auto Parts, NAPA) stock the widest range of sizes and usually install the battery free when you buy from them. This is the best option if your fob uses an uncommon size or if you want someone else to do the installation. Prices are competitive with other retailers.
Online retailers (Amazon, eBay, Newegg) sell batteries in packs of 5 to 10 for $0.50 to $2 per battery, which is cheaper than buying one at a time. Shipping takes 3 to 7 days. This option makes sense if you have multiple fobs or want to keep spares on hand.
Car dealerships will order and install the battery, but labor charges range from $20 to $50 on top of the battery cost. Use this option only if you cannot find the battery elsewhere or if your fob requires a special order.
How to install the battery yourself in five minutes
Most key fobs open with a flat-head screwdriver or a coin. Look for a small slot or seam on the edge of the fob and gently pry it open — do not force it, or you will crack the plastic. Once the fob is open, note which side of the battery faces up (usually the + symbol faces toward you), then lift out the old battery and drop in the new one the same way.
Close the fob by pressing the two halves together until you hear a click. Test the buttons to make sure they work. If the fob does not respond, open it again and check that the battery is seated all the way in and facing the right direction.
If the fob still does not work after you install a new battery, the problem may be a broken button contact or a dead circuit board, not the battery itself. In that case, you will need a replacement fob from your dealership or an aftermarket supplier.
Common mistakes that waste time and money
The most common mistake is buying the wrong battery size. Before you leave home, write down the exact code from your fob or take a photo. Do not guess based on what you think your car model uses — different years and trim levels sometimes use different sizes.
Another mistake is installing the battery backward. The + symbol should face up toward the fob buttons. If you install it upside down, the fob will not work, but the battery will not be damaged — just flip it over and try again.
Do not buy the cheapest battery you can find if it is from an unknown brand. Cheap batteries sometimes leak or die faster than name brands like Energizer, Duracell, or Panasonic. The price difference is usually only $1 or $2, and a reliable battery is worth it.
Finally, do not throw the old battery in the trash. Many retailers have battery recycling bins near the checkout or customer service desk. Batteries contain chemicals that can harm the environment, so recycling takes less than 10 seconds and is the right choice.
When to replace your key fob instead of the battery
If you have replaced the battery and the fob still does not work, the problem is likely inside the fob itself, not the battery. Water damage, a cracked circuit board, or worn-out button contacts can all make a fob stop responding even with a fresh battery.
A replacement fob from your car dealership costs $200 to $500 depending on your car make and model. Aftermarket fobs from retailers like Amazon or eBay cost $30 to $150 and work with most cars, though some require programming by a dealership or a locksmith. If your fob is old and you have already replaced the battery once, an aftermarket fob is often cheaper than paying a dealership to diagnose the problem.
Frequently Asked Questions
Can I use any CR2032 battery or does it have to be a specific brand?
Any CR2032 will work in your fob — the code tells you the size and chemistry, not the brand. Energizer, Duracell, Panasonic, and store brands are all compatible. Stick with a name brand if you can, because cheap batteries sometimes leak or die faster, but any CR2032 from a reputable seller will work.
How long does a key fob battery last?
Most key fob batteries last 3 to 4 years with normal use. If you use your fob heavily or live in a very hot climate, it may last only 2 to 3 years. You will know it is dying when the fob only works from a few feet away instead of across a parking lot.
Will the store install the battery if I buy it there?
Many auto parts stores and some big-box retailers offer free installation when you buy the battery from them. Call ahead or ask at the counter — it takes less than a minute and saves you the trouble of opening the fob yourself.
What if I lose my key fob and need a replacement right away?
Your dealership can order a replacement fob, but it usually takes 1 to 3 days and costs $200 to $500. Aftermarket fobs from retailers like Amazon or Best Buy are cheaper ($30 to $150) and ship faster, though some require programming. A locksmith can also make a replacement fob in a few hours for a similar price to the dealership.
Can I buy a key fob battery online and have it shipped to my house?
Yes, Amazon and other online retailers sell key fob batteries and ship them in 3 to 7 days. Buying in bulk (packs of 5 to 10) is cheaper per battery than buying one at a time in a store. This option makes sense if you have multiple fobs or want to keep spares, but not if you need the battery today.