That is the fixing bolt that my ctek battery conditioner is connected to, I have used ctek conditioners for many years if the car is going to be stood for a while.

 

When an older battery has such a deep discharge, it will seldom or never come back. It probably has some kind of internal short or other structural failure.

Never mind the fact that any 8 year old battery, even if it appears fine, is not. It has lost most of its capacity to ageing, ie sulfation of the plates.

Really you have two choices : get a new battery now, or charge the battery, maybe get it to last a little bit longer, then get stuck somewhere, then get a new battery.

Been there, done that. In fact, the battery in my 2015 is getting changed at 5 years, on the dot. Why go through the whole rigmarole of having it fail on you?

 

This is very strange behaviour for a Jaguar dealer. At least you can be confident in them not trying to sell you parts you don't need.

 

I was about to change to my new battery today but I saw this red cable connection. The new battery doesn’t have a port for it except a small hole that just looks like a hole and nothing else. So what should I do?

 

That‘s not a cable but the battery vent tube.
Just unplug it and plug it into the similar hole of the new battery.

 

Aha, I get it. I appreciate the help.