These are the 2 batteries listed for XKRs.
Anyone know by looking at the specs what one would serve better for a convertible XKR? I have a MTP93 in mine now. Both have the same warranty, the 93 has 850CCA and the 49 has 720CCA.

 

Group 49 is the spec' for our cars. Two biggest considerations, IMO, if considering an alternative would be making sure that it would physically fit in the availavle space, and would have the necessary venting for mounting in a confined space (needed for traditional lead-acid, but not for AGM batteries).

Maybe call Interstate and see what they say sbout those things.


This is a controversial topic, but my own take is that there is no reason beyond cost to install a traditional lead-acid battery at this point. AGM batteries are fully compatible with auto charging systems, and have these advantages:
- much slower self-discharge
- no venting of explosive gas or leakage of corrosives
- truly zero maintenannce

Not everybody shares this view, but there it is, FWIW.

 

You want the 93, it has the proper venting...the other one does not.

 

I installed the Interstate Megatron battery in my 2005 XKR about a year ago and it has been excellent. And as advised you will need to properly vent the battery. I believe the price was around $175-$200.

 

What # was it the MTP-93?

 

Yes, that is the recommended Interstate Megatron battery. The parts store just up the street from me has it for $115.

 

I really don't understand this Group 49 / Group 93 stuff at all.

My battery is from Autozone. Group 49, with the vent right where it ought to be.

The Deka site says Group 49 for our cars. They show Group 93 as an alternate but say the hold-down "may need to be modified".

Yet it seems Interstate says Group 93, right?

Go figure.

 

The Group 49s that I have used all had the Vent Connection.

Sometimes the Vent Connection was different than the original and a Adapter was supplied.

 

Thanks. I've had two Group 49s, both vented from the same spot (center right as viewed from above when installed) First one might have been OEM; not sure anymore.

In googling this, I found myself in a few beemer and mercedes forums where people were scratching their heads on the same Group 49 v. 93 question.

 

My recommendation for the Interstate MTP-93 was based on a footnote on their data sheet that this model was vented, and the MTP-H8 was not. Other manufacturers may differ.

 

Right. Good catch on your part.

Thing is, not everybody asks as many questions as we do arond here, so I bet more than a few people have, reasonably enough, ordered up a G49 to replace a G49 and then, finding no vent in the new one, just made do without. Not so good.

When they make me king, we will have a new rule: if a vendor wants to call something a G49 they must equip it with all the stuff a G49 is supposed to have. Vent included.
I guess the horse is dead by now, huh?

 

Just one more whack at that mule....My Jags since my 96 XJ6 have all used a group 49 battery. They do come with vents, at least all the ones I have bought. I recently changed the batteries in both mine and I found the vents there. I suggest checking for vents when buying just to be sure. Don't want that nasty hydrogen gas in the trunk! One thing I have noticed is that at places like Autozone and Advance Auto, the group 49 batteries are different ( white cases instead of black, different design details, etc.) from the other batteries, probably made by someone else.

 

I bought the 93, where is the vent? The 2 holes near the + terminal??
On the older jags there was a vent hose/tube that attached to the battery and vented the hydrogen outside the car, is this not the case with the newer jags

 

i got the 93....the vent holes are 2 holes by the + terminal?? on the top like 1/8th inch in diameter?

 

No, its the nipple in the center, by the label (see picture). Normally vented batteries comes with a vent adapter....you should ask your dealer if he did not give you one....sometimes they just throw them away.

See my pictures in this thread:
https://www.jaguarforums.com/forum/x...y-50185/page2/

 

After researching this subject, I have found that a AGM Type battery does not need, or have, a vent. The Remy Deka 9AGM49 at about $170 is used in a number of new German cars and should be a satisfactory replacement in the Jaguar. In fact, my Bentley uses this exact battery.

http://www.remybattery.com/Products/...9__9AGM49.aspx

 

Actually, some manufactures of AGM batteries will say that model XYZ is not suitable for vehicle ABC because of the lack of a vent. Their reason is that the remote vent is required in enclosed installations because of the battery will gas if the regulator fails in a overcharge mode. Optima is one of those vendors when quizzed about suitability for series 3 BMW's.

 

I think what they're saying might be more about lawyers than about technology.

An AGM will go its whole life without releasing the least bit of hydrogen, unless seriously overcharged. Even if that does happen, the amount of H2 released is very small compared to what we're used to with flooded cells.

I'd be completely comfortable running one in an enclosed space like the battery box on an XK. There's some mil spec that approves these batteries for use in enclosed areas. Not so with flooded cells.

 

Jaguar Recommendations!!!!!!!!!!!

TSB from 2002

bob gauff

 

I realize that this thread is kinda dated, but in reading the previous posts .. I was still a little bit confused. I may or may not have a deficient battery, but if I do .. gotta know what to order in. Existing battery says .. 65 H8 .. 2003 XK8 .. might even be original equipment for all I know.

Be that as it may, Group 65 was not part of your dialog above .. it was between Group 49 and Group 93. Johnson Controls are branded with many different monikers for most of the branded markets, so I figure .. what do they call what. On my XK8 .. it's the H8 sticker that nails it down .. for me anyway.

Purusing the linked PDF from JC, you will see that Group 49 IS the H8 .. the longest AMG in that family, and the big plus .. shows 900 CCA. Awesome! Guess I'll measure the dern thing to make sure though .. the 49 is exactly 1 1/2" longer than the 93. Cheers!

http://www.johnsoncontrols.com/conte...eet_101212.pdf