How to Replace Your Key Fob Battery — Guide by Car Brand
A dead key fob battery is one of the most common and easiest-to-fix car key issues. Here’s how to replace the battery in your key fob by brand.
Signs Your Key Fob Battery Is Dying
- Reduced remote range — you need to be closer to lock/unlock
- Intermittent response — sometimes works, sometimes doesn’t
- “Key Fob Battery Low” dashboard warning
- Push-to-start requires holding the fob directly against the button
Battery Types
Most key fobs use one of these batteries: CR2032 (most common), CR2025, CR2450, CR1632, or CR1620. Check your owner’s manual or the old battery for the type.
Ford / Lincoln
Battery: CR2032 (most models). Use a flathead screwdriver to pry open the fob seam. Replace battery positive side up. Snap closed.
Toyota / Lexus
Battery: CR2032 (Toyota) or CR1632 (Lexus). Slide the mechanical key out, use it to pry the case open. Replace battery.
Honda / Acura
Battery: CR1616 or CR2032. Use a small flathead to separate the case halves. Note battery orientation before removing.
Chevrolet / GMC / Cadillac / Buick
Battery: CR2032. Most GM fobs have a slot on the side — insert a coin and twist to open.
Nissan / Infiniti
Battery: CR2032. Slide the mechanical key out, then use it to pry the back cover off.
Hyundai / Kia
Battery: CR2032. Remove the emergency key, use a flathead screwdriver in the slot to pry open.
BMW
Battery: CR2032 or CR2450 (Comfort Access). Remove the mechanical key, use a small screwdriver to pry open the case from the key slot side.
Mercedes-Benz
Battery: CR2025. Slide the chrome bottom plate off, remove the battery tray.
Jeep / Dodge / Chrysler / Ram
Battery: CR2032. Slide the mechanical key out, pry the case open from the key slot.
Tips
- Use brand-name batteries (Duracell, Energizer, Panasonic) — off-brand batteries may not last
- Don’t touch the battery contacts with bare fingers — oils reduce battery life
- If the fob still doesn’t work after battery replacement, it may need reprogramming
- Replace the battery every 1–2 years proactively
Need Help?
If your key fob still isn’t working after a battery change, call S.A. Locksmith & Security at (210) 348-3677. The issue may be the fob circuit board, programming, or the car’s receiver module.
Frequently Asked Questions
Every 1-2 years, or when you notice reduced range. Proactive replacement prevents being stranded.
Not with push-to-start vehicles — you can hold the dead fob against the start button. But the remote lock/unlock won’t work.
Key fob batteries cost $3-$8. If you need a locksmith to replace it, expect $15-$25 including the battery.