So I am looking to keep my XJ on a battery tender. I'd prefer to keep it charged via a cigarette aux port, rather than via the battery in the trunk, but the one in the center glovebox is disabled when the car is off and no charging can happen. Is there another option?

 

Here's how I installed my CTEK battery maintainer. The cigarette lighter socket won't work because it's a switched circuit, which means that it's off (open) when the car is off, and electricity can't flow to the battery. Even if it could, I'm not sure if that might mess up the Battery Monitoring Module. I've had no problems with my installation and keep my XJ plugged into the CTEK whenever it's parked in my garage.
https://www.jaguarforums.com/forum/x...lation-130801/

 

I would not use the cigarette lighter either.
Follow Stuart's install as it's out of sight and well done.
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