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Key Fob Battery Replacement: Cost, Battery Types, and How to Do It Yourself

Before you spend $200 or more on a new key fob, check if a $3 to $10 battery swap is all you need. Most fob batteries take 2 minutes to replace yourself with no tools.

The $5 Fix

Key fob batteries cost $3 to $10 and take about 2 minutes to replace yourself. The most common battery type is CR2032, available at any pharmacy, grocery store, or online. No programming is lost when you swap the battery.

Signs Your Key Fob Battery Is Dying

Reduced range

You have to stand closer to your car for the fob to work. Normal range is 15 to 50 feet. If you need to be within 5 feet, the battery is low.

Multiple presses needed

You press the button once and nothing happens. Two or three presses finally unlocks the door. This is the most common symptom of a dying battery.

Intermittent response

The fob works sometimes and not others. It may work in the morning but not in the afternoon (temperature affects weak batteries).

Dashboard warning

Some vehicles display a 'key fob battery low' warning on the dashboard or instrument cluster. If you see this, replace the battery soon.

Delayed response

There is a noticeable delay between pressing the button and the car responding. A healthy fob responds within a fraction of a second.

Battery Type by Car Make

MakeCommon ModelsBatteryOpening Tip
ToyotaCamry, Corolla, RAV4, HighlanderCR2032Side notch to pry open
HondaCivic, Accord, CR-V, PilotCR2032Small Phillips screw on back
FordF-150, Escape, ExplorerCR2032 / CR2025Twist coin in slot to open
ChevroletSilverado, Equinox, MalibuCR2032Slide release on side
NissanAltima, Rogue, SentraCR2032Slide out emergency key first, then pry
HyundaiTucson, Elantra, SonataCR2032Remove emergency blade, pry case
BMW3, 5, X3, X5 SeriesCR2032 / CR2450Slide release tab on back
Mercedes-BenzC, E, GLC ClassCR2025Slide cover on back of fob
TeslaModel S, Model X (fob only)CR2032Pry bottom cover. Model 3/Y use key cards, no battery.
JeepGrand Cherokee, WranglerCR2032Slide out emergency blade, pry case apart
KiaSeltos, Sportage, ForteCR2032Remove emergency key, use it to pry case
SubaruOutback, Forester, CrosstrekCR2032 / CR1620Small notch on side to pry open
VolkswagenJetta, Tiguan, AtlasCR2032Flip out key blade, pry case from bottom
AudiA4, Q5, A6CR2032Slide release on back, pull out battery tray
LexusRX, NX, ESCR2032 / CR1632Slide out emergency blade, pry case

How to Replace Your Key Fob Battery

  1. 1

    Identify Your Battery Type

    Check the table above for your make, or look at the battery currently in your fob. Most fobs use CR2032. The type is printed on the face of the battery.

  2. 2

    Open the Fob Case

    If your fob has a hidden emergency key blade, slide it out first. Then look for a seam or notch along the edge of the fob. Use a small flathead screwdriver, coin, or the emergency blade to gently pry the case apart. Work slowly to avoid cracking the housing.

  3. 3

    Note the Battery Orientation

    Before removing the old battery, note which side faces up (+ or -). In most fobs, the positive (+) side faces up. Take a quick photo with your phone if you want to be safe.

  4. 4

    Swap the Battery

    Remove the old battery and insert the new one in the same orientation. Press it firmly into the clip or holder. Avoid touching the flat surfaces of the battery with your fingers; oils from your skin can reduce battery life.

  5. 5

    Snap the Case Closed and Test

    Align both halves of the fob case and press firmly until they click together. Test immediately by pressing the lock/unlock button. The fob should work at full range without needing any reprogramming.

When It Is NOT the Battery

  • Physical damage: Cracked case, missing buttons, or visible circuit board damage. A new battery will not fix physical defects.
  • Water damage: If the fob was submerged or went through the washing machine, the circuit board may be corroded beyond repair. Try drying it in rice for 24 hours, but replacement is usually needed.
  • Fob still does not work after a fresh battery: If you have verified the battery type and orientation are correct, the fob's internal electronics may have failed. You need a full fob replacement.
  • Vehicle does not recognize the fob at all: If the car's immobilizer does not respond to the fob even at close range with a new battery, the transponder chip or programming may be damaged. A locksmith can diagnose this.

Key Fob Replacement Cost

If it is not the battery, see full fob pricing

Save Money on Key Replacement

8 tips to reduce your replacement cost

Frequently Asked Questions

How much does it cost to replace a key fob battery?
A key fob battery costs $3 to $10 depending on the battery type. CR2032 batteries are the most common and cost $3 to $6 for a pack of two at most stores. You can replace the battery yourself in about 2 minutes with no tools required for most fobs. If you pay a dealer to do it, expect $15 to $25 for the service, which is not worth it given how simple the process is.
How often should I replace my key fob battery?
Most key fob batteries last 2 to 4 years. Smart key fobs that are constantly communicating with the car (proximity detection) tend to drain faster, averaging 1 to 3 years. If you have two fobs and rotate them, each battery will last longer. Replace the battery as soon as you notice reduced range or intermittent response.
What battery does my key fob use?
The vast majority of key fobs use CR2032 lithium coin cell batteries. Some Honda and Mercedes models use CR2025, some older Subaru models use CR1620, and some BMW keys use CR2450 for the larger Display Key. Check the back of your current battery or consult the table above for your specific make.
Will I lose my key fob programming when I change the battery?
No. Replacing the battery does not erase the programming on your key fob. The transponder chip and programming are stored in non-volatile memory that does not depend on the battery. Simply swap the battery and the fob will continue to work as before. If the fob does not work after a battery change, the issue is not programming loss.
What if my key fob does not work after replacing the battery?
If a fresh battery does not fix the fob, try the following: 1) Make sure the battery is inserted with the correct polarity (+ side up in most fobs). 2) Clean the battery contacts with a dry cloth. 3) Try a different new battery in case the first was defective. If none of that works, the fob may have internal damage (water damage, cracked circuit board) and needs full replacement.
Can I use a CR2025 instead of a CR2032?
CR2025 and CR2032 are the same diameter (20mm) but different thicknesses. CR2032 is 3.2mm thick and CR2025 is 2.5mm thick. A CR2025 will physically fit in a CR2032 slot but may make poor contact and drain faster. It is best to use the exact battery type specified for your fob. Both types cost about the same, so there is no reason to substitute.