Mazda’s owner’s manuals call for a CR2032 in the 2021 to 2024 models listed, and a CR2025 in the 2018 Mazda6 and the 2020 MX-5’s type A key.
Which Mazda?
The battery it takes
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Mazda key batteries by model
| Model | Battery |
|---|---|
| 2024 CX-5 | CR2032 |
| 2024 CX-50 | CR2032 |
| 2023 CX-5 | CR2032 |
| 2023 CX-30 | CR2032 |
| 2022 MX-30 | CR2032 |
| 2021 CX-9 | CR2032 |
| 2020 MX-5 (opens by pulling out the auxiliary key) | CR2025 |
| 2020 MX-5 (opens by sliding off a lower cover) | CR2032 |
| 2018 Mazda6 | CR2025 |
The 2020 MX-5 manual has two keys: type A opens by pulling out the auxiliary key, type B by sliding off a lower cover. The code on the old battery tells them apart too.
How to change it, in Mazda’s steps
Mazda recommends having the battery replaced at an Authorized Mazda Dealer, to avoid damaging the key. Its steps, from the 2023 CX-5 manual:
- Slide the knob and take off the lower cover.
- Press in the tab to unlock the upper cover, then lift it off with a tape-wrapped flathead screwdriver in the gap.
- Take off the cap and remove the old battery.
- Fit the new battery with the positive pole facing up, then refit the cap, the upper cover and the lower cover.
Mazda says not to touch the internal circuitry or electrical terminals, bend the terminals or let dirt into the transmitter. In the 2018 Mazda6, the auxiliary key comes out when you press the knob, and the manual says not to scratch or damage the rubber ring inside.
When the key battery is dead
If the transmitter’s buttons don’t work and its operation indicator light doesn’t flash, the battery may be dead, Mazda says.
To start the engine anyway, the 2024 CX-5 manual says to keep the brake pressed and, while the green push button start indicator light flashes, line up the center of the emblem on the transmitter with the center of the push button start. When the light stays on, press the button. Keep other keys and metal objects from touching the key while you do it.
Keep coin batteries away from children
The National Capital Poison Center says that if anyone swallows a battery, immediately call the 24-hour National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222. Don’t delay. Immediate treatment decreases severity.