I've looked through threads and it's not clear to me whether my car needs AGM battery or not. The owner manual or workshop manual does not say either. And online, I see both offered for my car. If I do parts search on a Jag site it comes with C2P24168 but does not say the size of AGM or not. My current batter says T8-90J on top but that's not helpful either (it is not the original battery)

Is there a reference doc somewhere listing the proper battery type for 2012 XKRS? I know lots of people use AGM, but is this what Jag calls for my car?

 

Give this a read. Your OEM is standard lead acid battery (vented) aka battery wet.

There are comments from Brutal who is a long time contributor and a Jaguar Tech. You can trust his comments.

https://www.jaguarforums.com/forum/g...battery-76529/

 

If i understood it correctly, stock battery is not AGM then, right?

 

Correct.

 

Are you sure about this??

My 2010 XKR has a AGM charging system and a AGM battery. A lead Acid would not make sense in this car.

 

My 2012 had an OEM Jaguar flooded battery replaced in 2014 by the dealer. Also the charging system doesn't care if it is a flooded or AGM battery . Based on what I have read the AGM battery performance is better then the flooded but either one can meet the needs of the car.

 

I've got AGM in both my '07 and '10 XK/XKR

Zero flaws or electrical issues.

In fact, when I got my 2010, it had a 12 month old Lead acid, so I swapped it with the AGM from my 2007XK. Sure enough, the XK went nuts on a 600 mile drive. CD Audio kept cycling. Radio would turn off withing minutes.... Various little things I hear common complaints about.
When I returned from that road trip, I tossed the older AGM back in my '07XK, and bought a new AGM for the XKR.

My automotive world is a happy one now, and still no need for a battery maintainer after what....4 years on an AGM?

Got a perfectly good (yea, right) Lead acid with 73 months left on warranty setting on a shelf...

Vince

 

Yes sir. The OP identified the correct OEM part number for his 2012 XKRS.

C2P24168 is a battery wet.

https://www.jaguarlandroverrenoparts...Y4LWdhcw%3D%3D

While the OP is asking for the proper battery for his car, and he's indicated the OEM part number, the service manual for 2010 acknowledges either flooded (battery wet) or AGM, so it appears JLR doesn't care, they just install Wet batteries. The standard warning on all AGM batteries is one of prolonged overcharging. "Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive."

I've not personally heard of anyone experiencing an overcharge issue and "long drive" isn't defined. I have no issues with my flooded battery and see no issues with using AGM.

Q&C, I looked in the service manual of your 2010 and found no reference to a unique (AGM) charging system. I'm not disagreeing with you. I just didn't see any documentation on it in the service manual so I can't provide any input.

From the 2010 service manual:

Battery and Charging System - General Information - Battery Care Requirements
Description and Operation
1. INTRODUCTION
This document sets out the requirements for care and maintenance of batteries and thereby the standard of battery care at dealers and retailers for new vehicles
This applies to all types of 12 Volt Lead Acid Batteries used in Jaguar and Land Rover vehicles whether they are conventional flooded technology or Absorbed Glass Mat (AGM – also known as Valve Regulated Lead Acid (VRLA)) technology and also applies to both Primary and Auxiliary Batteries. AGM batteries offer improved resistance to cycling as seen in stop start applications.

 

How do you know specifically that its not an AGM? Everything tells me that it is. Perhaps the wet battery description is the confusion. An AGM is also a wet battery.

 

AGM batteries are sealed. There are no caps to add distilled water. and they aren't vented but yes, you're correct, they are both wet.

Perhaps I should have mimicked JLR in the service manual and referred to it as "Conventional Flooded" or flooded as Jagtoes indicated, so apologies for any confusion in my vernacular.

Again, I can't speak to your specific vehicle and don't doubt you have an AGM, but am responding to an OEM part number.

 

As a manufacturer whose survival depends on specifying the right battery and charging environment, (look at Samsung phone problems) and someone who has spent 500hrs on battery research, I cant see a single reason Jaguar would use a SLA (sealed lead acid) in the center of any car 2010 and up. Just from the safety factor alone. When it leaks it will eat through the car in the most vulnerable area.

The downsides are exponentiation and there are no upsides whatsoever to using a SLA. It makes no sense to me. But I will defer to those who know for certain as I dont.

I can say this, you will reduce alternator life if you charge an AGM with a circuit made for SLA. Putting an SLA in a system designed for AGM will give you shortened battery life.

Based on how we hardly see alternator problems on this forum, and plenty of shortened battery life, all fingers point to our car being designed for AGM.

Most importantly, AGM categorically addresses the problems a car like an XKR/s has, infrequent use and short trips. Thus lowest self drainage during periods of rest and quicker charge during short trip.

Gel batteries and then Glass Mat were invented specifically to stabilize liquid Acid- gel converts it to thicker substance, glass mat absorbs the liquid entirely. I cannot understand why one would put liquid acid inside the passenger compartment, on a crossbeam no less. And get lower output, slower charge, reduced life, faster discharge, more weight.

What am I missing? I do tend to give Jaguar engineering the benefit of doubt and may be erroneously biased as result.

 

Feel free to call or write JLR and report back to us Q&C.

I've answered the OP's question.

Stock OEM battery for his vehicle was Conventional Flooded battery.

 

Sean this is more of a learning process for me, not a debate.
Forgive me I have to ask again to learn. How do you know that the stock OEM battery is a SLA. Also how do you know its not an AGM?

Its not possible to distinguish a SLA from AGM visually

 

I looked into the battery issues when I was investigating the "smart" charging system. From the dealer I got a factory info bulletin on battery selection. If I remember correctly, it stated that if the car came with a flooded battery, that is the only one to be used as a replacement. If the car came with AGM then use it.

In my case the info came a bit late as I just replaced my flooded battery with an AGM. Since the Jaguar charging system is a "smart system" it expects the kind of battery impedance (internal resistance) in the charging circuit as installed at the factory. According to Jaguar, installing the incorrect type battery will result in less than ideal battery charging operation.

Having said that, I stayed with my AGM and the car is behaving normally for at least 1 year now.

 

If you keep your AGM battery on a CTEK or other maintainer that is designed to charge both wet cell and AGM types, even though your alternator (that was designed for use with a "flooded" or wet cell) won't fully charge that AGM battery, your CTEK will keep it fully charged.

Interesting that the OEM battery in my 5.0L XJ is AGM, whereas the 5.0L XKR OEM battery is wet cell, just like my 4.2L XKR. AGM is clearly the better technology, since it supposedly holds a charge longer than wet cell.

So, the question is: Assuming all other factors being equal, will a flooded/wet cell and AGM battery last the same length of time if they are both maintained daily on a CTEK? If so, then why spend the extra money for an AGM battery? Or is AGM, by its chemistry, inherently superior and longer lasting and, therefore, worth the incremental cost? Any electrical engineers out there?

Stuart

 

Stuart,
I can simplify the equation.
Say that you have 2 batteries of identical construction/chemistry.
One is twice as large as the other- the large one will last more than twice as long. Here is why:

All batteries have a certain number of times they can be used- aka cycles.
The number of cycles is determined by how much you deplete it.
So a battery will do 500 cycles if depleted to 25% before recharging. That number goes down to 200 if you deplete it to 50% each time before charging it. (Which is what you would be doing with the smaller battery in the above equation)

The reason an AGM last many times longer is that you are not depleting it as much due to 3 factors.
1.They dont self discharge as much
2.They charge up faster
3.They can safely deliver more energy- a regular battery cannot drain more than 25% of its power capacity without destroying its capacity permanently. See how you can reduce the cycles of an infrequently used XK by letting it get below a certain mark, because its draining even if you had nothing connected to it.

p.s my charger has a specific mode for AGM batteries.

I have to ask as a matter of learning, how do you know for certain the battery in your XKR is not AGM? It will shed a lot of light as you apparently have both .

 

Again my apologies for missing the question Q & C. When I referred to the standard "Battery wet conventional flooded batteries" that were installed on our vehicles from the manufacturer, I didn't relate it to an SLA. The OEM units from JLA aren't sealed batteries.

Again, it goes back to my old school thinking whereas Battery wet (in my misused vernacular) have caps to replenish the electrodes and are vented.

SLA vs. AGM is a different discussion and I couldn't tell them apart without a label either, but perhaps others can.

 

Jaguar certainly has created a ton of ambiguity about their battery.

On my car they made a big fuss about not jumping the car, and what battery to do it with, and not hurting the unique charging system.

 

Indeed. According to this Bulletin, you could assume some cars had AGM and some had flooded. Which ones had AGM is the mystery. You would have to look at hte battery, which was probably already switched out in 2010-2013 cars....

 

In 2010 they changed the charging system in the XK. It is a smart charging system designed to reduce drag to give you better mileage. The neg. terminal has a charging module that provides information to the ECU and TCU. If you check out the cost of a 2007-2009 alternator vs the 2010-2015 you will see a difference. The older alternators would usually run at 14V all of the time while the newer system will discharge and charge the battery as the system requires. My 2012 replacement batter is an OEM (has a Jaguar Leeper on it ) and it is a flooded , vented wet battery. I suspect when it goes I will replace it with a AGM. For you guys with a 2010-2015 car if you use torque pro or have the lighter volt meter just plug it in and watch the different voltages when you drive. I bought a 2016 chev truck and it has the same type of system. I watch my volt gauge and it runes from 12v to 15v and it is random.