I just replaced 09 xk battery with AGM because of multiple discussions in the forum about advantages of AGM batteries. There is some question whether AGM should be placed in the xk 07-13 models because they accept charge differently and could possibly get overcharged and explode!! It seems many of you have placed agm's in your xk's, Jaguar recommends them in the older xk8's but not newer xk's. Wonder if this has to do with alternator recharge voltage. Has anybody out there had a problem with AGM after having it for a while?

 

I've owned the car for two years. In the first year I replaced the battery three times because of the electrical gremlins - primarily the touchscreen issues.

The third battery, the AGM, was installed a year ago and I've not had any electrical problems since. I do not use a battery tender and more often than not I leave the car unlocked with the fob inside in the garage. The car has not exploded yet.

Interstate warrantied the batteries and I just had to pay the $$ difference between the lead acids and the AGM. I feel the price difference was well worth it.

Best regards,

 

I have had my AGM battery for almost a year. I was having touchscreen issues and transmission gremlins. However, they went away after I switched to the AGM battery--for a while.

Some of the problems come back if I haven't driven the car for a while (a week or more if in cold weather). The car is not a daily driver, and I don't use a battery tender.

 

About a year, maybe a tad less...
Flawless to date.....

 

Do you know how much energy you would have to apply to get a battery with that much capacity to explode???

An AGM battery accepts deeper and longer charges, as well as more frequent charging. Your car does not the ability to over charge an 880 amp battery (with all of the other circuitry in the car) to the point of explosion. More over, the charging system is intelligent enough charge your battery to a potential and then stop charging until the potential falls below a particular threshold. The stop charging is a little more involved if it were explained accurately but the concept applies.

I had an AGM battery in the 07 XKR I had for over a year and have had an AGM in my 2010 for the 2 years I've had it. I have never experienced any of the electrical gremlins others have (thankfully).

There is a reason why many of the high end car manufacturers put AGM batteries in theri cars.

I have never heard the thing about 07 - 13 XKR's and AGM batteries. That is hard for me to believe...not calling you a fibber, I would just have to see some hard technical evidence before I would believe that.

 

I've yet to see a person with these supposed battery problems ever detail what the current draw was/is on their cars with the key in the locked position or even with the key just to off after thirty minutes.

The 2007 manual says it should be less than 35ma if no other non factory items are installed on the car.

 

Have my AGM battery in now for approx. 10mths. My xkr has always been my daily driver. The electrical issues I experienced previously have not returned. The only change was the battery. So that was obviously the culprit. The most unusual electrical problem I had was for the touchscreen and radio turn off soon after I drove away. It all turned back on in an instant but then my hazard lights were flashing. Really weird the elec issues that can arise from the battery saga. As I said no problems since.

 

anyone worrying about an AGM battery exploding should worry more about a conventional battery exploding ........... because AGM's require a higher charging voltage.

i suspect that the battery charge problems in the later model years of all models relates to the ECM charging control. many manufacturers have dabbled with turning off or reducing battery charging according to software algorithms with the goal of decreasing fuel consumption.

i would just rather have a fully charged battery thanks.

 

U can put a Fluke meter on that has a 24 hour recording that will trace whether ther is a electric draw issue or whether the battery cant keep it up. The Fluke meter can also give u a paper read out. I am not criticizing the xkr, but my experience has shown that new batteries arent the issue. Hi line cars often have problems. The more sophisticated the car, the greater the chance of an electrical issue. A 2013 xkr rag top has, under definition, at least 32 computers. Please do the math. I think the xkr is a great car, you just have to know what keeps it happy!

 

The issue isn't "the battery exploding" - it's the warning that AGM batteries suffer if you charge them at too high a voltage. From the workshop manual:

The implication is that conventional batteries don't have this limitation, and thus the voltage regulation is less critical. We know Jaguar recommends replacing like with like. The concern would be that, in a car with a voltage regulation system designed for conventional batteries, there is a chance that it might apply too high a voltage to an AGM unit. However, it seems that no-one has experienced any problems along those lines. The only thing we don't know is whether damage is 'silently' occurring that will shorten battery life - so far, based on what I've read here, we know they last 2 years without issue.

It's probably no problem at all, but that's the question that's been raised.

 

Thanks guys for all the useful posts! I am sure I made the right decision to upgrade to the AGM, it is just a better battery for cars with high electrical demands. I don't know enough about car electronics to be a "fibber" about it, just relating what I heard from someone with more knowledge than me. That's why I come to the forum to figure this stuff out from people with experiance with these great cars!

 

I knew that was the case.

Not only will an AGM battery work better, it will last longer.

Enjoy your Jag- you may have a collector's item in a couple years!

 

Great post fellows, very timely; conclusion? think I'll put an AGM in my wife's XK8 first !

Adrian

 

For the record the 09 xk convert. is my wife's, I drive the 10 xk coupe. I never told her about the exploding battery theory, didn't think she would be interested!

 

A question on Jag batteries.

BMW has different charge profiles for AGM and non-AGM batteries, as well as either technology as the battery ages.

Voltage applied from the alternator is adjusted to allow for both issues. New batteries must be registered (type, date installed, amp-hours) in the power management controller to set up the system.

Does Jag do something similar in its recent cars, or is it "install and go"?

 

Interesting...is that true for all BMW cars?

Don't know of any setup that is required in software for Jaguar cars - I've never experienced anything like that.

I'm grateful my Jag does not require this.

 

It's on all recent cars (last 10 years at least). The manufacturer data on its effect on battery service length is not available, of course, but the logic of lowering charging system demand, and thus manufacturing costs, makes sense. Perhaps because of German/Euro demands, the engineers spend a lot of time improving CAFE efficiency. I assume this is one of their approaches.

To pursue a question relevant to Jag, is it your practice to replace with a Jag battery, or (like most knowledgeable BMW owners) do you replace with an aftermarket equivalent with no ill effects? Which one, if so?

 

This is the full battery installation procedure from the manual:

I don't know what the reset procedure is - perhaps you do enter the battery type and capacity.

Interestingly, they have this warning:

There is no corresponding warning about fitting AGM batteries to cars fitted with a flooded battery as standard.

 

In my 2007 XK manual there is no mention of the BMS at all. I suspect that BMS is a for newer cars than my 2007 and I have a suspicion that the BMS is only for recording when the last battery was installed and not for any other reason. I'm just guessing and nothing more than guessing.

 

Hmm - looks that you're right - BMS only appears in the 5.0 manual.

However, it does more than that.