I have a very low mileage XJL (2017), It does sit sometimes for weeks but too often I get a diagnostic after cutting the car off, that reads "restart the engine batter needs charged". Any others and suggestions please?

 

Chuckmeister, check out https://www.jaguarforums.com/forum/x...-power-241729/. That should have a few ideas for you. The big thing is you need to invest in a CTEK battery maintainer. This device is not a standard battery charger per se, but something that gives a small trickle charge to the battery every now and then. That will solve your issue. The big thing is just remembering to unplug the unit before driving off.