I have a 2016 Nissan Altima and need to change the battery in my FOB. I have 2 FOBs and the second one was secured in a safe place and never used. Question: do i need to change the battery in the second FOB also? thank you

Better change both batteries just to be safe.

I agree with Brad, especially going into the colder weather change both at the same time

Change both

Generally speaking battles that are being used or not can wear down in power. The smart thing is to change both batteries at the same time. AND use the good FOB I tilt to replace the battery in the first one. Like they change your smoke alarm battery every 6 months good or not.