Toyota bZ4X / bZ key fob battery
Every model year listed for the Toyota bZ4X / bZ has a proven battery. The most common answer is CR2450. Rows below run oldest to newest; a year can appear twice when the car came with more than one kind of key.
- 2026Smart key (electronic key)
CR2450
Owner's manual: manua.ls (checked Nov 1, 2026)
Manual text: “Use a CR2450 lithium battery”
Find CR2450 on Amazon
Changing the battery
Smart key (push-button start)
- Most push-button fobs hide a metal backup key. Press or slide its catch and draw the key out first.
- Look inside the empty key slot for a notch. Put the tip of the metal key or a small flat screwdriver wrapped in tape there and twist gently until the shell splits.
- Before you take the old cell out, look at its face. Put the new cell in with the same side showing, and avoid touching both faces at once.
- Snap the halves back together, slide the metal key home, and press each button, then try the start button from the driver's seat.
On most Toyota smart keys the metal key slides out after you press a small release, and the case opens at the slot it leaves behind.
A CR2450 is 24.5 mm across and 5.0 mm thick, much fatter than a CR2032. A thinner cell will rattle and lose contact, so buy the exact size.
Keep spare coin cells away from small children. A swallowed coin cell can burn the throat within hours; if it happens, go to an emergency room at once.