Key battery replacement question

[Cortez]

Hi all. I've read all the posts regarding this topic and am ready to do the DIY key battery replacment. There is one thing I'm not sure of though.

At the moment, I only have one key (it only came with one from the used car dealer). I have successfully reprogrammed the keyless entry a few times using the one-key method so I know this part of the process works. However, if I remove the battery and replace it with a fresh one, will the transponder still allow me to start the car after it has been isolated from a power source? I'm not sure whether removing power for a short time from the transponder unit in the key will result in a non-functioning key.

If anyone could clarify whether the transponder will continue to function correctly after the battery replacement, I would feel much more comfortable about going ahead with this.

Thanks

[btmed]

I replaced the battery in one of my keys and it still started the car but could not reprogram it to lock unlock the doors.

[romeokc10]

If you have another vehicle that you can drive do yourself a favor and send your key to the guy in the link below. I just had my key repaired buy him last week and it works better than new, it only costs $55!

BMW General Module 5 (GMV, ZKE V)