2032 Battery you need - https://amzn.to/4aoqN09

Here is a quick and easy video on how to replace the battery in your Toyota key fob. The model number on this fob is MOZBR1ET. If your fob looks like this one, the process will be similar regardless of the model. The first step you will to do is to remove the mechanical key and use that to pry the two halves apart using the slot I've shown. Once you have that apart, you will need to use a small flat top screwdriver to pry out the dead / weak 2032 battery. You need to be delicate with the small plastic tabs that hold in the battery. Replace the dead battery with a new 2032 coin cell battery + side facing upward. Clip the two halves back together and replace your mechanical key. You're all set! No need to reprogram! I hope you found the video helpful!

OEM 2018-21 TOYOTA C-HR SMART KEYLESS PROXIMITY REMOTE FOB MOZBR1ET 89904-F4020
FCC ID: MOZBR1ET - 0010
PN: 89904-F4020
Frequency: 315 MHz
Battery: CR2032
2018 - 2021 Toyota C-HR
2018 2019 2020 2021 2022 Toyota C-HR
CHR battery change