There is a list of things to do after a battery reset Steve. I've condensed it down to a PDF check-list which I can send to anybody who might want it. The checklist also includes the "back-door" method of bypassing the radio code if you don't have it to hand.
Hi Derek, My s type has a Varta G3 95 AH 800 fitted by Jaguar. As Paul says, the S type does like efficient battery, and minor electrical items such as heated windows, radio, etc will shut down when the battery is failing. This is the Big Cat telling you that starting the car is far better than listening to the radio. Regards, Peter.