Like the other guys have said, invest in a CTEK. Just disconnecting the battery isn't enough IMO - you need to keep the battery conditioned and the CTEK does that. Jaguar themselves sell the CTEK, branded to Jaguar, for a lot more money than the regular CTEK you can buy on the net.

I hooked mine permanently to the auxiliary battery terminals behind the small cover on the left side of the trunk. Positive to the obvious positive terminal there and negative to any convenient bolt or screw. Then all you have to do is connect the permanently installed fly-lead to the lead on the CTEK when you put the car away. It takes about 20 seconds to do it. The CTEK can be left on indefinitely as it has clever circuitry to prevent problems from overcharging etc.

This is the one which, I believe, most of us who have them use:


Here's how I installed mine:

This pic shows the positive terminal behind the cover in the trunk. The rubber cap is in the way - the CTEK fly-lead connector is attached by removing the nut, placing the fly-lead connector and replacing the nut.


This shows where I made the ground connection.


This is all you see in the trunk after installation.

 

Have a quality tender on there now, and it is helping. As I previously stated I have a new battery onboard but after a lot of reading, I am going to get an AGM and install it, seems to be a better ticket for all the electrics.

 

Unless you need a new battery again, I'd save the money. Your regular new battery will be fine for the car so long as you either drive the car all the time or use a CTEK (etc) to maintain the battery in good condition. The problems seem to arise when even good batteries are allowed to discharge a little due to lack of use of the vehicle and the Jaguars apparently need a full charge for all their systems to function well. Now you have the tender, your new battery should give you many years of problem free service.

 

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