I've recently been getting more frequent "low battery" warnings on my '11 XJL 5.0L naturally aspirated V-8 with a battery that is approximately 2 1/4 years old. I do frequent daylight trips of perhaps only 10 to 60 miles.

Suggestions?

 

You could use a meter to check if it's true, and if so explore why.

 

John, one of the things that you need to look at is how long are you sitting with the car in the "RUN" state with the engine not running (ie, depressing the START/STOP button without your foot on the brake). I have found that if you sit like this for say 5-10 minutes, the car will give a warning that the battery is "low". This can also happen (atleast to me) if you are going in and out of the vehicle a lot and not locking the door. The interior lights remain on and it will slightly discharge the battery enough that the car has an issue with it.

Running the car for 10+ minutes should be enough to return the battery back to 100%.

Like JagV8 states, if in doubt, put a meter across the battery in both the OFF state (should read 12.6 VDC, anything less than that normally indicates that the battery is getting low or you have a 10+ amp load running in the car with the engine off) and with the engine running (should read 13.7 VDC during steady state, may see up to 14.4 VDC immediately after starting the car, but it will coast down to 13.7 once the ECM thinks the battery is back near 100%). If you need more info on this, let me know.

 

Thanks Guys, I appreciate the good info. I think in dawned on me why I got the messages. I just washed the car the day before, so I had the doors, trunk and hood open quite long doing the sills, vacuuming, window interiors, etc. This vehicle has a ton of lights, inside and out that one doesn't notice during daylight hours. My bad.

 

I have found if this automobile is turned off and if you're going to be away from the vehicle for several minutes or longer it should be locked. With all of the electronics etc. on this automobile the battery gets worn down quite quickly if it is not locked.

 

Again, I totally agree.

Locking the car shuts down superfluous electricity consumption.

Not only that, it prevents unauthorized opening of the car's doors and trunk. With my Corvette, once I walk away with it's key fob, nobody can open the doors or trunk; not so with the Jag.

 

Does the XJ battery require maintenance (topping off with distilled water) or is it sealed?

 

i know this is an old thread, but i wanted to say thanks cuz this is good info. I was removing the inspection stickers and such from my car this weekend and after less than 10 minutes with the doors open i got this warning, so i completed the task with the engine running (and the garage door open). but when its in my garage, i NEVER lock it. it didnt occur to me that a bunch of stuff was running at all times if it wasnt locked, so i will start doing that. Great tip.

 

Yes, lock the car whenever you leave it. I've also noticed you will get the warning message even if the battery is fully charged. I feel like it's on some sort of timer that throws up the message after a period of time.

Also look into getting a CTEK charger. I have a few of them and to me the 7002 is the best all around charger for the money.

 

I'm very pleased with my CTEK MUS4.3. Search for my thread on how I installed it. The older model CTEK 3300 is sold by Jaguar dealers and is co-branded with the Jaguar Leaper logo. Compare features, prices and customer reviews on Amazon.

 

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