Toyota Prius Prime / Prius Plug-in Hybrid key fob battery
1 of the 4 model years listed for the Toyota Prius Prime / Prius Plug-in Hybrid have 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.
- 2023-2025Smart key
Not confirmed yet
- 2026Smart key (electronic key)
CR2450
Owner's manual: manua.ls (checked Nov 1, 2026)
Manual text: “Lithium battery CR2450”
Find CR2450 on Amazon
Changing the battery
Smart key (push-button start)
- Start by freeing the hidden metal key: there is a latch or slide on the case, and the blade comes out once it moves.
- 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.
- Pop the old battery out with a toothpick or plastic pick, not a metal blade, and seat the new one with the + side matching the old one.
- Reassemble, refit the emergency key, and check that the car sees the fob when you press start.
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.
If a child might have swallowed a coin cell, treat it as an emergency and get to a hospital right away.