Well it is with deep regret I have to tell you all I have had to replace my XF battery.
It has lasted well at 9 years old but Monday night when I went to put the car into the garage it had nothing in it and I had been using the car for a few good runs the last week.
So ordered a new one off eBay an Exide one at £89.99 and the nice people at eBay gave me a special discount of 20% off so cost me £72 and as I owned a S type before, that the battery bolt seized in when I bought my XF, I took the bolt out and covered it in Coppa slip and it came out now easy.
It doesn't seem so long ago that batteries rarely lasted more than 3 years, so some things are getting better, despite what all us old boys claim.
The last one I replaced was on my previous XJ, at 11 years quite possibly unnecessarily, as the apparently random warning lights illuminated turned out to be caused by a defective wheel speed sensor. My own fault for jumping to conclusions just because of the date on the battery, and Jaguar's reputation for being over sensitive to their condition.