The short answer: most Honda Odyssey key fobs use a CR2032 3V coin-cell battery, though a few older or alternate fob designs may use CR2025. Always verify by checking the battery inside your fob or the owner's manual.
Common battery sizes you might encounter
Honda has used a couple of coin-cell sizes across years and trim levels. The CR2032 is by far the standard for most current fobs, while CR2025 appears in some older or regional designs. Both are 3V cells, but they differ in diameter and thickness and are not interchangeable in all fobs.
- CR2032 — 3V coin cell, the most common for recent Odyssey key fobs
- CR2025 — 3V coin cell, found in some older fob designs
If your fob seems to be wearing out or the replacement battery won’t seat properly, double-check the exact model year and fob design in the owner's manual or by calling a Honda dealer.
How to replace the battery
Replacing the battery is a quick, non-invasive task you can do at home with minimal tools. The steps below assume a standard two- or three-button Honda Odyssey fob.
- Carefully pry open the fob along the seam using a small flat blade or coin, taking care not to scratch the case.
- Inspect and remove the old battery, noting the orientation of the positive (+) side.
- Insert a new CR2032 or CR2025 with the correct polarity, ensuring it sits flat in the contact springs.
- Snap the halves back together until they click, then test the remote from a short distance to confirm function.
Tip: If the remote doesn’t work after replacing the battery, recheck the polarity, or the fob may have a separate issue such as a damaged circuit or worn button contacts.
Where to buy and verify compatibility
Coin-cell batteries are widely available at auto parts stores, electronics retailers, pharmacies, and online. To avoid buying the wrong size, confirm the exact battery size before purchasing.
Buying options and quick checks
Check the fob or the owner's manual for the exact battery size (CR2032 vs CR2025). When in doubt, take the old battery with you to a store to match it, or ask a staff member to confirm compatibility with your Odyssey's model year.
- Honda dealership or service center
- Auto parts retailers
- Online retailers and electronics stores
Concluding: Replacing the battery is a simple maintenance task that can restore remote access quickly; if the fob still won't respond after replacement, your issue may be with the key fob itself rather than the battery.
Summary
For most Honda Odyssey models, the standard replacement battery is a CR2032 3V coin cell, with CR2025 as a possible alternative for older fobs. Always verify the size by inspecting the battery or consulting the manual, replace with the correct polarity, and test the fob after installation.