Thought this might be of help for people with the new shape XJ X351 but one of the older chassis models, like mine from 2010.

I noticed some water on the top of my battery cells.

These are not start-stop ones, so they used lead acid batteries, i found out from Jaguar that YOU CAN NOT use the newer AGM batteries on them as they charge differently and have different electronics.

You have to get a lead acid replacement which is the Jaguar Varta RC150 950amp cca (cold crank amperage) and 90AH rated capacity one.

Looks like I will be booking this in as the water on top of the battery is of concern, plus the crappy lifetime I am getting out of a full charge.

 

apachegogo,

Many current model XK/XKR forum members have replaced their OEM lead acid batteries with AGM batteries and reported no problems. It's your car and, of course, your choice. There's a lot of discussion about the pros and cons of switching to AGM on that forum.

In either case, be sure to always use a quality battery maintainer such as a CTEK 3300 or CTEK MUS 4.3 (those are USA models, not sure of the UK equivalents, but you can check their website) to keep the new battery fully charged. I use the CTEK MUS 4.3 and am pleased with it. Note that CTEK manufactures the Jaguar-branded acccessory maintainer. Also, be sure to always lock your doors even when parked in your garage to shut down the computers and keep your car keys (smartkey transponder) at least 25 feet away from your parked car to avoid waking up the computers and draining the battery.

Hope this helps,

Stuart

 

Another thought - could the water on the top of the battery be caused by overcharging and boiling out the electrolyte? You might want to get the charging system checked.

 

Stuart-
Does your above advise also apply to the new XJ (X-351) as well?
Thanks,
John

 

John,

I'm simply reporting that there has been a lot of discussion of AGM replacement batteries on the XK/XKR forum. Since I'm not an electrical engineer, I'm not qualified to provide any definitive advice. But you can draw your own conclusions from the thoughts of others - see below.

There are many threads on the XK/XKR forum about AGM batteries, and you can search that forum if you wish. I recommend reading this thread:

https://www.jaguarforums.com/forum/x...attery-110970/

Stuart

 

adding to the above comments: recently got from my dealer a promotion April is National Car Care Month. It says: "Battery: Even if winter isn't especially cold where you live an aging battery is a less powerful battery. You should consider replacing it if it is older than three years."
Although I've owned numerous cars have never been concerned about a battery issue since I have gotten at least 6 years battery life for those other vehicles.
Because of many questions I've seen on the Jaguar forum re battery life I will take the time to get mine checked since it's a 2012 XJL-at the three year mark.
And, just to repeat another comment made--always lock the car whether you run for a brief minute to the grocery store, gas station, etc. and when you put this automobile away for the evening in the garage or parked outside.

 

THanks for the info Stuart, I rang and spoke to 2 different Jaguar dealers in 2 different cities (intentionally to get another opinion). They both said similar stuff as you said, you can try it, the AGM version is a lower cold crank and generally better cycle but you DO HAVE to keep it topped up as you don't want an AGM to fall below 50% charge.

I felt lead acid would be the safest way to go, as I only want to use my CTEK charger in the winter when i absolutely have to. But yeh agreed on the keeping it locked and the key far away bit.

RE overcharging, its the first time I've seen water come up, if anything I've had problems with the battery not charging up well enough. As it dies quickly without regular topups, so I think the alternator/charging is ok. Might just be a dying battery.

 

So I ended up replacing the battery altogether with an Exide EB950 (800cca cold crank amp rated 95AH capacity)

I googled this around and the garage also said its common replacement for that Varta RC150 one, it has a higher capacity but lower cold crank but he said it will be fine.


Anyone replaced with this one before?