Key fob batteries
What battery does my car key fob take? CR2032, CR2025 & CR2450
- 4 sources
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Quick answer
Almost every car key fob runs on a single 3-volt lithium coin battery, and the fastest way to know which one is to read the code printed on the old battery. The three you will see most are CR2032, CR2025, and the bigger CR2450. The numbers are the size: the first two digits are the width in millimeters, the last two are the thickness in tenths of a millimeter.
Common key fob batteries: match the code on your old cell.
Duracell CR2032 Panasonic CR2032 (uncoated) Panasonic CR2025 Energizer CR2450The three key fob batteries side by side
| Code | Size (width × thickness) | Rated capacity | Where you see it |
|---|---|---|---|
| CR2032 | 20.0 × 3.2 mm | 225 mAh (Panasonic) | Very common in car fobs |
| CR2025 | 20.0 × 2.5 mm | 165 mAh (Panasonic) | Some slimmer fobs |
| CR2450 | 24.5 × 5.0 mm | 620 mAh (Energizer) | Some larger fobs, such as the Jeep Wrangler's |
CR2032 and CR2025 are the same width, so either one will drop into the other's slot. They are not the same battery. See CR2032 vs CR2025 vs CR2450 before you swap one for the other.
How to find your fob's battery in 2 minutes
- Check the owner's manual. Look up "key fob" or "battery replacement" in the index. Jeep's Wrangler manual, for example, names the exact cell (CR2450) and shows where to pry the case open.
- Or open the fob. Most fobs have a small slot along the seam. Many hide a metal key you slide out first, and the slot is behind it. Use a coin or a small flat screwdriver and twist gently.
- Read the old battery. The code (CR2032, CR2025 and so on) is printed on the flat face. Before you lift it out, note which side faces up so the new one goes in the same way.
Guides in this section
Keep coin batteries away from kids: a swallowed coin battery can cause serious injury. Put the old cell somewhere safe right away and recycle it.
How we work: sizes and capacities come from the Panasonic and Energizer datasheets. Car examples come from the carmaker's own owner's manual. Sources are listed below.
Questions people ask
How do I know if my car key fob takes a CR2032 or CR2025 battery?
Open the fob and read the code printed on the flat face of the old battery, or look up "key fob battery" in your owner's manual. CR2032 is very common in car fobs, but some slimmer fobs use CR2025 and some larger ones use CR2450, so check rather than guess.
What do the numbers 2032, 2025, and 2450 mean on a coin battery?
The first two digits are the width in millimeters and the last two are the thickness in tenths of a millimeter. Per the Panasonic and Energizer datasheets, CR2032 is 20.0 mm by 3.2 mm, CR2025 is 20.0 mm by 2.5 mm, and CR2450 is 24.5 mm by 5.0 mm. All three are 3-volt lithium cells.
Will my key fob lose its programming when I change the battery?
For most cars, no: swapping the battery does not erase the fob's pairing. A few models do ask for a short resync after a battery change, and the steps are in the owner's manual. Swap the battery quickly and keep the fob close to the car the first time you try it.
Sources
Last checked Oct 23, 2026. WARNING: Lithium coin batteries are a severe ingestion hazard for children. Keep new and used cells locked away and check your vehicle owner's manual for exact fob specs.
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