Key fob batteries typically cost between $3 and $10 per battery, depending on the type and where you buy them
The price you pay depends on three things: the battery chemistry (lithium coin cells are more expensive than alkaline), the specific model number your fob needs, and whether you buy from a big-box retailer, a pharmacy, an auto parts store, or a dealership. A CR2032 lithium coin battery — the most common type in car key fobs — costs around $3 to $5 at Target or Walmart, $4 to $6 at CVS or Walgreens, $5 to $8 at AutoZone or O'Reilly, and $8 to $15 if you buy it from a car dealership. Dealerships charge more because they often install it for you; the battery itself is the same.
Most key fobs use one of four battery types: CR2032, CR2025, CR2016, or CR1632. The first three numbers tell you the diameter and thickness in millimetres. Your owner's manual or the fob itself will say which one you need — look on the back or inside the case. Buying the wrong size will not work at all, so check before you go to the store.
Key Takeaways
- A single key fob battery costs $3 to $5 at drugstores and big-box retailers, and $5 to $8 at auto parts stores.
- Dealerships charge $8 to $15 but usually install the battery for you as part of the price.
- Your owner's manual or the fob case itself will tell you which battery type you need — CR2032, CR2025, CR2016, or CR1632.
- Buying batteries in bulk packs of four or eight costs less per battery than buying one at a time.
Where the price difference comes from
Dealerships mark up batteries heavily because they are selling a service — removal, replacement, and testing — not just the part. When you pay $12 at a dealership, you are paying for someone to open your fob without breaking it, swap the old battery for the new one, and make sure the buttons work before you leave. If you do it yourself, you pay only for the battery.
Auto parts stores like AutoZone, O'Reilly, and Advance Auto Parts fall in the middle. Their prices are higher than Walmart or Target because they stock a wider range of battery types and because some locations will install the battery for a small fee or for free. If you already shop there for other car maintenance, buying your battery there saves a trip.
Drugstores and supermarkets stock only the most common types — usually CR2032 and CR2025 — but their prices are competitive because they sell high volume. Walmart and Target often have the lowest per-unit cost if you buy a single battery, and their return policies are straightforward if you buy the wrong type by mistake.
Buying in bulk saves money per battery
If you have multiple key fobs or want to keep spares on hand, buying a pack of four or eight batteries costs less per unit than buying one. A single CR2032 at Walmart costs around $4, but a pack of four costs roughly $8 to $10 total — about $2 to $2.50 per battery. Online retailers like Amazon sell bulk packs of 10 or 20 for $6 to $12, bringing the per-battery cost down to $0.60 to $1.20, though you pay for shipping unless you have a membership.
The trade-off is shelf life. Batteries in sealed packaging last five to ten years, but once you open a pack, the unused batteries can lose charge over time if they sit in a drawer. Buy bulk only if you actually use the batteries within a year or two, or if you have several fobs that need replacing soon.
How to avoid buying the wrong battery
Before you go to the store, find out which battery your fob needs. The easiest way is to open the fob and look at the old battery — the model number is stamped on the flat side. Write it down or take a photo. If the fob is broken and you cannot open it, check your owner's manual; most list the battery type in the maintenance section. You can also call your car dealership with your vehicle's year, make, and model, and they will tell you the battery type over the phone at no cost.
Do not guess. Putting a CR2025 in a fob that needs a CR2032 will not work because the thickness is different and the battery will not make contact with the terminals. The fob will appear dead even though the battery is fine.
Installing the battery yourself versus paying for installation
Opening most key fobs takes a flathead screwdriver or a coin — you slide it into the seam and gently pry the two halves apart. Once open, the old battery pops out and the new one snaps in. The whole job takes two minutes. You do not need any special tools or training.
If you are uncomfortable opening the fob or worried you might break the plastic, paying a dealership or auto parts store to do it costs $5 to $15 depending on where you go. Some auto parts stores do it for free if you buy the battery from them. Call ahead and ask; policies vary by location.
Lithium versus alkaline batteries in key fobs
Most modern key fobs use lithium coin cells (CR2032, CR2025, CR2016) because they hold a charge longer and perform better in the small, high-drain environment of a fob. Alkaline button batteries (like LR44 or LR1130) are cheaper — usually $1 to $2 — but they drain faster and do not last as long in a fob. Some older fobs use alkaline, but if your fob was made in the last ten years, it almost certainly uses lithium.
Lithium batteries cost more upfront but last longer, so the total cost per year of ownership is actually lower. A lithium CR2032 lasts two to four years in a typical fob; an alkaline battery in the same fob might last six months to a year. The math favors lithium unless you only need the fob occasionally.
What to do if your fob battery keeps dying quickly
If you replace the battery and it dies again within a few weeks, the problem is usually not the battery — it is the fob itself. A corroded battery contact, a cracked circuit board, or a stuck button that drains the battery constantly will kill even a new battery fast. Open the fob again and look for green or white corrosion on the metal contacts inside. If you see it, clean it gently with a dry cotton swab or a pencil eraser.
If the contacts are clean and the battery still dies fast, the fob may have a hardware problem that a new battery will not fix. At that point, you can buy a replacement fob from a dealership (usually $100 to $300), a locksmith (usually $50 to $150), or an aftermarket supplier online (usually $20 to $60). The aftermarket fobs work with most cars but may not have all the features of the original.
Frequently Asked Questions
Can I use any CR2032 battery in my key fob, or does it have to be a specific brand?
Any CR2032 will work as long as it is a genuine lithium coin cell, not a counterfeit. Duracell, Energizer, Panasonic, and Maxell are all reliable. Avoid very cheap batteries from unknown sellers online; they may be old stock or counterfeits that do not hold a charge. Buy from a pharmacy, big-box store, or established auto parts retailer.
Why does my dealership charge so much more than Walmart for the same battery?
Dealerships charge for labor and convenience, not just the battery. You are paying them to open the fob without damaging it, install the new battery, and test it. If you do the work yourself, you pay only the battery cost. Some dealerships will install a battery you bought elsewhere for a small fee.
How long does a key fob battery last?
A lithium coin battery in a key fob typically lasts two to four years with normal use. If you use the fob heavily — pressing buttons dozens of times a day — it may last only one to two years. Alkaline batteries last much shorter, usually six months to a year in a fob.
What should I do with the old battery after I replace it?
Lithium coin batteries are recyclable and should not go in the trash. Take them to a battery recycling program, an electronics retailer that accepts batteries, or a hazardous waste collection event in your area. Many auto parts stores and pharmacies have battery recycling bins near the checkout.
Can I replace a key fob battery if the fob is waterproof?
Yes, but you need to be careful about the seal. After you open the fob and replace the battery, make sure the rubber gasket or O-ring is clean and sits properly in the groove before you snap the halves back together. If the seal is cracked or missing, the fob may no longer be waterproof. Some waterproof fobs use a different battery type — check your manual first.