Hope someone can help. 

I have an Octavia 2014 with keyless entry and keyless start/ stop. 

Car is warning that I need to replace the key battery. 

Is it a simple case of just changing the battery,  or will the key need any kind of coding or reprogramming after swapping the battery?

Also I have a spare key that's totally flat.  I've changed the battery,  but the key neither remote unlocks the car,  or allows it to start.  Is there anything I need to do to match the spare key back to the car locking or ignition?

 

Many thanks

Ian

Have a look at this thread:-

 

You might need to re synchronise your keys..

 

I've got KESSY on my car and was surprised at how short the interval was between when you first get the low battery warning and the car no longer responding.  I've had to replace my batteries twice now and each time it's been no more than a couple of days, so whatever you do, don't put it off!  In my experience, a new battery lasts 18 months to 2 years, but that obviously depends on how much you use the fob.

 

Changing the battery itself is pretty straight forward - there are several videos online for all VAG group cars.  Just be aware that part of the cover slides sideways as you remove it - don't use too much force to try and pop it open - a small flat head screwdriver will do the job.

 

I've not had to do anything to resync the fobs after replacing a battery, but I have checked both of mine out immediately after making a replacement, just to ensure they're both in sync again.

I've changed my KESSY keys, perhaps 5 times in total.

There is no "reprogramming" involved after replacement & taking out & replacing the battery is straight forward.

 

Maybe a week after you see the first "battery low" message you may find that the KESSY part of the functionality stops working, but you can still use the fob buttons to unlock/lock the doors normally.

I used my key like this for a month or so without problems.