Not out of the question that my 2010 is ready for a new one. Off warranty so I will do what I always do and grab the right specs from Costco. Noted on a youtube video on jump starting an XF that there is a monitor on the negative terminal that the dealer calibrates when a battery is replaced. Seems like a ploy to get you to the dealer for battery replacement.

FYI the best place to put the neg terminal clamp when jump starting is the wing nut top that holds the spare tire down.

 

Has anyone done their own swap?

 

That little device on the Neg post is actually measuring the exact amounts of current that are being discharged AND charged at any given moment. It sends that info to the computer which then issues warnings depending on the charge/discharge ratios.

Yes, if you charge your battery you should put the charger's negative lead outside of the post, because if you put the lead directly on the post the measuring device will not see your charging currents and will issue low batt. warning even when the battery is fully charged.

Jaguar seriously should fix their electrical system. Many of us have had our batteries changed on new XJ(L) 2011-2012 cars in just one year. I know I had mine changed 2 weeks back (12 months old) and already got a low batt. warning after not starting the engine for only 4 days. Just a VERY BAD design of the electrical power management.

Albert

 

I would recommend Duralast Platinum H8 AGM batter from Autozone. Check out the specs, they are superb and it's a very easy swap. Also, Autozone will test your battery for free.

 

From the research that I have done......I agree whole heartedly !

 

Will check it out. Has anyone done swap without calibration of that neg terminal module?

 

Update
Came back from another flight and dead flat. Not enough to even activate locks. Boosted. Got home. Jag dealer price for new battery was $180 which I didn't think was high enough to warrant costco shopping as I heard they didn't carry the group 49 Batts.

Swapped it myself and it certainly has more grunt than the prior even when it was fine.

I don't buy that the module on the neg post needs calibrating. The voltage is inherently variable so it needs to adapt to any level and situation. Parts guy said to just swap em.