Originally Posted By: Vikas
Originally Posted By: Apollo14
Keyless entry fobs are always on, so last approx 2 years although sometimes much longer.
Really? I thought they used RFID detector inside the car.
If the keyless entry fob is always on, there is no way it will last for 2 years! It will be dead in days if not in weeks.
I think the reference is to the kind with a remote built-in, such as for a Nissan. My dad's key looks like this one:
The key itself is solid metal with no apparently place for an RFID tag. It can be easily pulled out of the remote portion by removing a screw and just yanking it out. Now I suppose there could be some sort of RFID placed in the remote portion. Could even be on the main board.
I don't know for sure if there's any separate RFID like with a Honda key. I suppose I could find out by having it duplicated to an ordinary metal key. I have rented cars that used similar keys with a "switchblade" button release.
I wouldn't imagine that it's always on. I've work in the electronics industry including on battery powered devices. There are certain standby modes that barely use any power, but I don't know why that would be necessarily with a keyless remote entry system. I would think it would only have to power up when a button is pressed. Of course the receiver in the car would need to be on.
I've had all sorts of remotes last a long, long time on an old battery. Often I just figure I might as well replace it so I don't have to in the future. Maybe I'm just bored. My big worry is about leakage, which supposedly can be worse the greater the discharge a battery has.