[FunkyDuckling]

for my 2016 Mazda, the keys do not need a battery to operate.

you instead need to hold the fob up to the start button and it will work passively, rather than just being in the car normally. Glad they still give manuals with cars as I had to learn that without service.

[SV_BubbleTime]

There are three systems to the key, the doors and remote start, the “passive entry” which requires the battery, and the backup RFID you’re talking about.