I have had my s type with the electronic handbrake which caused me some trouble.
I have now made sure that my battery is always charged [Thank you CTEK] and only one problem in the last 5 years which was cured with a new battery.
Peter.
+1 for the CTEK chargers, a must if your cars not in daily use
keeps the battery tip top, got a Jaguar on my S-type R and never had any warning lights in over 6 years, well recommended
cheers
Joe