It was over a year ago, but it I think it was $300. Easy install, no issues.

 

2011 XJL - where is the little battery located? This car gets only about 10 miles of stop and go daily so no surprise low battery warning is showing. Will put on charger.

thx In Advance!
Donm

 

Donm, the car is in the boot/trunk of the car on the right side. If you open the hood of the car, there are jumper points there that you can connect a battery charger to. I use these points to power my vacuum pump when changing my oil.

 

Thermo and Donm The small Start/Stop battery was first introduced in the 2013 model year. Prior to 2013 this feature was not available.

 

The little auxiliary battery is for the Stop-Start system that began with the 2013 model. Your 2011 XJL has only one battery and it's in the trunk. I recommend that you use a CTEK brand battery maintainer. Here's how I installed mine:
https://www.jaguarforums.com/forum/x...lation-130801/

You may need a new AGM battery. Here's the one I bought and recommend:
https://www.jaguarforums.com/forum/x...attery-212478/

 

XJsss, I read 2011 XJ and battery with a low voltage condition. I totally missed the "small battery" bit. I just assumed that they meant the main battery.

 

I meant 10 miles round trip, oops!

im looking for the positive post under the hood for attaching a charger but none insight. Looked in the fuse box as there was a battery + symbol on its cover.

any clues for me, 2011 XJL, v8

regards,
donm

 

It's under the hood closer to the passenger side. It'd be the upper left corner if your standing in front of the vehicle with the hood open. If I remember correctly, I think there's a small plastic piece that needs to be removed. The posts should be underneath it. Take a closer look at that area. It'll jump out at you.

 

 

I have not read all this string but I sought the advice of jaguar regarding the issue in my XJ supersport 2010.
I have recently replaced the battery with a 10amp hr better battery its now 100qmp hr.
​​​​​​It still does warns me after a few minutes....this backs up what the jaguar tech said.

He told me that the car will warn you even though the battery is fine as a safety measure to avoid a dead battery. Whether they adjusted the software to give you longer is is a maybe. Either way I have uses it for a good hour and just turned the car on and off when needed for a few seconds.

The car does cycle through a discharge process occasionally to calibrate the battery. So I would guess the if you turn off the car during this cycle it could be at a minimum.

I used my old battery while camping as a power source... It lasted a week charging all electronics with no problems so it had plenty of juice. It was 10 years old.... Impressive.