This morning I checked resting voltage of both batteries. The main battery, which was replaced two days ago, tested normal. No surprise there. The auxiliary battery is nearly dead. This is the one I specifically asked the SA to check.

Back the car goes this week for new "free" battery, lol
John

 

Mine sat locked for three weeks. This morning when I got in it I had no battery message. I stopped for gas and stood next to it with it unlocked for a whole five minutes. When I got in it I had the battery message. I started it and drove it twenty miles at 40 to 50 MPH and came home never saw the message again. Is it just software saying that anytime you leave it unlocked without the motor running for more than say 3 minutes? That seems to be the only time I get the message. As long as I lock it everytime I get out it doesn't give me the message. Even if I sit in it with the radio playing I don't get the message.

 

The story is that the mechanic did not install an AGM battery as is required. That caused most all of the issues. Also found the auxiliary battery to be faulty. I asked if the non-AGM battery might have damaged the charging system, and the answer was "no." I'll get the car back tomorrow.

John

 

Problem resolved at dealership today. They replaced both batteries( glad for warranty) at 17,000 miles and 3 years. Dash message went away and the ECO start/stop feature works again.

 

I have seen this warning on my '11 XJ V8 on a regular basis since purchasing it in April 2016 at 57K miles. A new battery was installed in ~November 2015 based on the battery date of manufacture. Since I don't have the stop/start option (thankfully), I don't have a second battery. I drive over 50 miles/day at 70+ mph, with numerous instances of the revs being above those during cruising. The car has always started flawlessly, with no signs of a low battery. I have chosen to ignore the warning.

 

I think the warning is triggered by something else. I was cleaning my leather interior on the 2011 XJL Supersport this morning, had several doors opening and closing during the time, and despite having a battery tender attached throughout, still saw the dash warning appear quite a few times. The message would come on then go off again as doors were held open. I checked and saw that the battery tender constantly indicated a full charge regardless of the dash warning's presence.

 

I have had the same experience. It only occurs when I open the driver's door. Odd.

 

Did you figure out the issue with the "Start engine battery low crap".. I have the 2011 XJL 5.0 Aspirated and I have the trickle charger in all night fully charged and always get this message, Whats the fix here if anyone knows. :-(

 

I'm curious about a fix as well. I just bought a '12 XJL super sport and the low battery message several times while cleaning the car. Since I had no idea how old the battery was I decided to replace with a new one (Duralast Gold) to rule out the battery. Then, saw the low battery message the other day.

 

I’ve had this same issue. When cleaning the car or just tinkering around, I quite frequently leave the doors open. After doing this several times, I received the low battery message on the dash. I purchased a trickle charger and connected to the battery terminals in the trunk. The trickle charger states that the battery is full, but I still received the low battery message.

What I did to resolve this is purchase a battery charger from Lowe’s for about $100. After purchasing it, I began using the battery terminal underneath the hood, as opposed to the terminals in the trunk. This truly recharged the battery. Also, if I’m going to be working on my car for an extended period of time with the engine off, I’ll keep it connected. Jaguar dealers also use this method. After making these minor changes, I’ve never seen that low battery message ever again.

I’ve never tried using a trickle charger on the terminals underneath the hood. That may work. Someone can give it a try and report the results. From personal experience, a legitimate battery charger will work if using the terminals under the hood. Tip: Never ever start your car with any sort of charging device connected to it! I hope this helps.

 

Hmmm wow interesting and thanks for sharing. I have a little 1.5 amp slow trickle charger hooked to the battery in trunk shows green light fully charged, long 5 ft cable pigtail so i just pop the trunk quick disconnect door closes on cable just fine weather stripping cushion. You said you bought another charger at Lowe's, why didn't you just put your initial trickle under the front hood and try that before getting a new one? Its funny that it would work under the front hood better because the battery is in the back where my charger is, doesn't make sense hmmm. Did you just hook it up to the positive and negative terminal under that black cover you had to remove under the hood? I have to figure this out I'm sick of looking at the battery low start engine every day....

 

Im still trying to figure this out too, when you replaced the battery did you just plop it in yourself?? I heard from some it has to be taken to the darn dealer for programming which I WONT be doing and some say they just put it in themselves. Hopefully I can just drop it in.. I heard these Jags are very sensative to the slightest batter drain and cant fall under certain volts or that notice comes on. Someone on here said to put a good battery trickle charger under the hood and not at the battery in the back and he never saw the message again. If you find out anything let me know and I'll do the same.

 

I replaced it myself, I lost the one touch window operation and trunk close button operation which had to be re-set but thats easy.

I am not a tech but I have read from multiple sources that electrical gremlins are much more impactful on modern cars. Also, batteries are not trustworthy. So, I don't hesitate to throw money at a battery and am probably going to return the new battery I just bought because I don't trust the battery--even though its new.

 

When you said you replaced the battery yourself you lost the window operation and trunk close button that had to be reset, was that an easy fix and how did you do that? Didn't understand what you meant when you returned the new battery you didn't trust, was your old one ok or did you just get another new battery.. :-)

 

When I replaced the battery, three things happened :

1) Trunk would not power close, but would close manually, then would work normally after that. I cycled it a couple of times to be sure.

2) Had to reset the clock, and temperature units on the instrument display.

3) Got a message about parking brake requiring calibration. This is super-easy, follow the on-screen instructions, hold the brake pedal and apply the parking brake. Done.

I don't seem to have one-touch window close. How do I reset it?

 

Ok thanks much for the info I will definitely make note. I heard when you replace the battery there is a module next to the battery that has to be reset and has to be hooked up to an OBD 2 reader and must be reprogrammed or things wont work etc etc etc,,yawn!!!.. after you replaced it did the low battery start engine light go off permanently??

 

Hold the window up button for 2 seconds after they close then run them down all the way and hold the button for 2 seconds. This should reset the auto up and down. Also you may have to follow this procedure for the sunroof.

 

I’ve replaced the smaller eco start/stop battery. I have the means to do the “programming” after I swapped the battery, and I didn’t. My common sense kicked in and said that it’s just a battery. Essentially your just telling the vehicle that a new battery was installed. Everything worked completely fine. No problems.

Keep in mind, a dealer’s service department is their biggest source of profit. Every time a service tech connects SDD to your vehicle for “programming”, there’s a charge.

 

The battery module with eventually relearn the new battery but I think I read where it might take a month. The best method is hook it up to SDD and do a battery relearn service. Mine has been doing the same thing for the last 6 months. I check the status and we are down to almost 50% battery. The auto start stop quits working at like 70% or something. The SDD will tell you the exact capacity of your battery.

 

Just curious, how much did the little battery set you back?