When I bought my car back in 2014 I also got all of the previous owners service records. I recall something about the battery so last night I looked at them. They installed a new battery on April of 2014 and I purchased the car at that time. So in 3 months the battery will be 5 years old. I have had the car on a smart charger ever since buying it so I didn't anticipate a problem but can't determine it's goodness other then a voltage check. So this morning I pulled my Ctek and inserted a volt gauge. As we all should know the stage 7 Ctek maintenance charge is 13.7 volts. Car is up on the lift and locked. after 8 hours I just checked the digital volt gauge and it is at 12.8 volts. By the way it was at 12.8 V at around 1:00 pm and has not changed. I didn't do a load test so I can't get a feel for it's status but I will have the dealer go through the standard battery test in April when I get my annual oil change. By the way it is the "Jaguar" brand flood battery that was dealer installed.

 

IIRC, a fully charged battery should yield at least 12.54V after standing for 24 hours. Battery checks seem, to me, to be pretty hit and miss - I was having issues with a previous 2004 XKR and suspected the battery. I took it to a battery shop who tested it and deemed it fit for purpose so "couldn't sell me a new one". I ordered an new Varta online and when fitted all my problems (well the car-related ones!) went away. So the shop tested itself out of some business.

If you're not having random electrical issues and have kept it on a CTEK your battery is likely fine.