Mazda key fob battery

Many Mazda advanced-keyless fobs use a CR2025, others use a CR2032, and some older remotes a CR1620.

Battery	Used in	Size	Capacity
CR2025	Mazda (most common)	20 mm × 2.5 mm	≈ 165 mAh
CR2032	Mazda (also used)	20 mm × 3.2 mm	≈ 225 mAh
CR1620	Mazda (older models)	16 mm × 2 mm	≈ 75 mAh

CR2025, CR2032, CR1620 at the same scale.

Mazda: starting with a dead fob

On most newer models, touch the start button with the key; older Mazdas have a key slot to insert it into.

Not sure which you have? See CR2032 vs CR2025: same look, different size.

To change it: release and pull out the metal key, twist its tip in the seam to split the case, and fit the new cell the same way up. Step-by-step guide.

Also mainly CR2025: Mercedes-Benz.

Key types change between model years; the code on your old battery is final.