Last week my battery light was fluctuating on and off for several days.
It was happening during a heat wave of 100 degrees plus, so I knew it was somehow related. After posting the problem here, Brutal suggested that the battery cables might be the cause. Turns out he was correct in that assessment. They were heating up, increasing the resistance and dropping the voltage enough to cause the light to come on.
The dealer told me that the same exact thing happened to someone else last week, exept their cables got so hot the car nearly caught fire.
This issue is something I've never heard of before. Is this a jaguar only problem or is it common? I've been working on cars a long time and never ran into this one.

 

Happened on my old '00 Hyundai Sonata when it was about 6 years old.