I've recently purchased a 2011 XKR convertible. I've had to jump a few times. The key was never cut so I can't get in the trunk without power. Twice I used the access behind the left rear tire. This time I think it went dead because I left the remote in the holder over night. So when I wanted to start it this time I decided to hook the charger up and leave over night to charge the battery. But when I checked it this morning the charger had a red light to indicate no charge. I hooked up the jump box like I have before that worked and nothing. When I hook the ground there are sparks showing me I got a good connection. So I pulled the back seat and tried that access point and same result.

When these issues first started, I pulled the battery and it's only a year old and checked out as good.

 

If your battery is now completely dead, it will suck the juice out of a jump box. Be aware... jump boxes only supply power for about three seconds before they are also depleted.
It would seem you have a dead battery, going by what you've stated. Is your alternator proving enough power to charge?
If you have this problem, you'll need to sort it out or you will keep killing batteries.
And. Get a Key Cut!

 

The box isn't dead. There should at least be enough to pop the trunk. I'm getting the key cut tomorrow.

 

Box dead, as in not enough to start the engine. I'd say the near-dead car battery is sucking up all the power provided by the jump box, preventing the voltage from reaching the solenoid.
Course I may be talking out my butt also.

 

for a moment i thought this thread was going to be about getting all four wheels off the ground, at speed. my heart skipped a beat.

 

The jump box is fully charged and capable of starting multiple cars on one charge.

I just noticed with jump box nothing happens but with the charger I get blinking interior lights and noises coming from the doors just like when there's very little left in the battery.

 

This is typical behavior when you have a completely discharged or dead battery. Usually only a high amp charger/starter (like those big ones on wheels at service shops) can drive enough current in and still maintain a high enough voltage at the computers in the car to start these cars.

Small chargers will draw down the voltage due to the high standby load to reboot the electronics and be unable to charge.

Jump boxes, even though they may claim very high currents, cannot maintain those currents with the minimum voltage needed to run the computers when starting.

 

Thanks WhiteXKR, you were right. I got a 200 amp charger and it started right up!

My first XKR was a 2000 Coupe. I would never have bought another one without the multiple times WhiteXKR and many others helped me figure out how to fix whatever was the issue at hand. With the extensive help of the Forum members, I've felt comfortable to purchase 2 XJR's and 8 XKR coupes and convertibles. I have to pay as little as possible so most of these Jags had high miles, know issues and even a few salvage titles. Therefor there has been many sleepless nights hoping I could figure out and fix the issue for much less then taking it somewhere. I'm proud to say I've never gone to a dealer. I have used Dr. Jaguar near Orlando on a few occasions. He's amazing and even has a British accent. I've been lusting after a 510hp beast since they first came out and with my recent purchase of a 2011 XKR Convertible, I want more...................

 

*ugh*
Some people's kids, I guess.