I have an odd issue. The battery in my remote control only lasts around 3 days. I have changed it 3 times in a week. 

I can lock the car OK, walk into the office. When I come back, I cant unlock the car and need to go through the process of using the key in the boot, setting off the alarm, and inserting key into slot. 

Get home form work and I cant lock the car. Replace remote battery. Car locks. I get in the next morning - `smart key not found- insert smart key into slot` - Insert the key and all goes ok.

3 days later. Get to work, and I cant lock the car. Process repeats.

The batteries are Duracell, so they're not cheap, but why on earth are they running flat in just a few days? This never happened until recently. I have stripped the remote to see if there permanent send issues, but all seem fine.

I really don't want to be asking the dealer for a new key!!!

Do you have a second fob or just the one? Guessing a button is broken in you fob draning the battery. Maybe worth getting cheap replacement off ebay or jag dealer not too expensive to get a new fob.

Took to an independent Jag specialist who sorted me a new key. All good now, thank you.