A Honda key fob battery is a 3-volt lithium coin cell. On most push-button smart keys made in the last decade, that cell is a CR2032. On many older flip keys and remote heads, it is a CR1616. A smaller group of early remotes uses a CR2025. The number stamped on the cell already in your fob is the one to buy. A model-year chart is only a shopping hint.
This site is an independent guide to that swap: which cell, how to open the shell without cracking it, what it costs, and what to try when a new cell does not bring the doors back. It is not affiliated with Honda Motor Co., Ltd. Honda, Civic, Accord, CR-V, and the other model names are used so you can find the car you drive.
Which battery to buy
| The fob you have | The cell to look for |
|---|---|
| Smart key, push-button start, emergency key hidden in the fob | Usually CR2032 |
| Flip key or a small remote on a car you start with a metal key | Usually CR1616 |
| Older compact remote whose cell says CR2025 | CR2025, which is thinner than CR2032 |
Read the full comparison on what battery a Honda key fob takes, then use the size chart when you are choosing between model families. CR2032, CR1616, and CR2025 are not interchangeable just because they are round.
How the swap works
On a smart fob, slide the metal emergency key out and twist a coin in the notch it leaves. Do not pry the seam with a screwdriver. Note the plus mark in the cup, fit a name-brand lithium cell the same way, and click the shell shut until the gap disappears. You do not program the fob afterward. The steps, including the screw-open method for older remotes, are on how to replace a Honda key fob battery and how to open the shell.
If the car will not lock, or will not start
A fob that only works when you are touching the door usually needs a new cell, not a new key. A warning on the dash about the keyless remote means the same thing. If the cell is already flat, hold the fob against the start button, press the brake, and press start. That uses the immobilizer, which does not need the coin cell. The door key hidden in the fob still unlocks the driver door.
- Low battery warning
- Start the car with a dead fob battery
- Fob dead after a battery change
- Why a battery swap does not need programming
Model guides
The shell changes even when the cell does not. A 2016 Civic and a 2023 Civic both tend to use CR2032, and they do not open from the same memory of a video. Start with the model you drive. Year-by-year notes are published on a schedule so each one can be checked on its own, not dumped in a single batch.
What a new cell should cost
A name-brand CR2032 or CR1616 is a few dollars at a pharmacy or an auto-parts counter. Panasonic, Murata, Energizer, and Duracell are the usual reliable choices. A dealer can fit the same cell and charge labor. A new programmed smart fob is a different purchase, often hundreds of dollars, and it is not the remedy for a weak coin cell. Skip rechargeable LIR cells and unmarked bulk trays.
Plan on two to four years from a fresh cell. Heat on a dashboard, a spare fob left in the car, and a shell that is not fully closed all shorten that. More on those cases is added over the coming weeks, one guide at a time.