battery group interchangeability?

The standard battery size for a '91 XJ 4.0L is group 58. But I noticed that many other groups have higher capacity. Even group 58-R, which is the exact same size with poles reversed, has an extra 50 CCAs or so.

Does anybody know which groups will fit in the jeep? I'm looking for maximum storage capacity, as measured in cold cranking amps (CCA).

Thanks.

I think the regular BCA Group 34 will also fit - whatever the standard size for Optima is.

And, if you're willing to do a little work, you can fit pretty much ANYTHING in the back - just run wiring to it. You can do that with a sheetmetal ground to a good, heavy spot - and get away with just running the "hot" lead forward - which simplifies wiring. You've got to really prepare your grounds for that to work, but I've done it on quite a few vehicles, and I plan to do that with my 88 when I get around to adding the two deep cycle batteries, relocate the starting battery, and clean up all the auxiliary power distribution wiring (I was in a hurry...)

5-90

Ok ... I just went to the Interstate Battery website, and looked it up.

Their Mega-Tron group 58 - MT-58 - 75-month battery has the following specs:
Weight: 28.80 pounds
Length: 9.50 inches
Width: 7.25 inches
Height: 6.88 inches
Cranking Amps: 675
Cold Cranking Amps: 540
Voltage: 12
Termination: A

The MT-34 has the following specs:
Weight: 38.50 pounds
Length: 10.25 inches
Width: 6.88 inches
Height: 7.75 inches
Cranking Amps: 875
Cold Cranking Amps: 700
Voltage: 12
Termination: A

So ... you see that the same line of battery has an extra 160 CCA in the 34 group vs. the stock 58 group.

For size:
The 34s are 0.75 inches longer, 0.37 inches more narrow, and 0.87 inches taller. These are not big differences in size.

So ... if it fits well ... I'd go with the 34 any day.

Why, pray, are you looking for a boost in CCA? Or are you looking for a longer reserve capacity?

I merely ask for information - I'm just trying to get my head around what you're doing...

5-90

Longer reserve capacity. It's just a beefier battery. Can hold more charge in case your alternator goes bad and you're in the middle of the Mexican desert or something. More reserve in case you're starting in -20* temps and the motor doesn't want to start right away.

montanaman said:

Longer reserve capacity. It's just a beefier battery. Can hold more charge in case your alternator goes bad and you're in the middle of the Mexican desert or something. More reserve in case you're starting in -20* temps and the motor doesn't want to start right away.

Click to expand...

Then you want to look at a marine/Start battery like the Exide stowaway line.
Stowaway Marine/RV Dual Purpose Battery - 24 Month Warranty - 12 Volt

BCI Group Size 24 CCA
at
0° F CA 500
at
32° F 625 RC Minutes 120 @ 25 Amps
Part Number heigth Width Height
ST24DP625 10-3/16 6-13/16 9-7/16 70Ah

There is a 2 1/2" spacer under the battery tray you need to cut down because of the height.

If you're looking for reserve capacity and an ability to go low without suffering damage, a marine battery might be a good option, because they're often deep cycle batteries. But you often sacrifice some initial cranking power for the size.

Just make sure you measure height so the posts don't hit the hood, especially with a marine battery that may have additional screw posts, and of course you may have to modify cables if you get a European type battery, whose posts are reversed. I haven't measured the lengthwise space available, but one hefty option might be the "euro-diesel" style battery, which is rather long and wide, but low in height. I don't remember what the type number is off top of head, but look for the OEM style battery for any old Mercedes diesel. Lotsa cranking power in those!

That said, I'm not sure I'd go to that much trouble if the issue is emergency reserve. It might be both cheaper and easier to leave it stock, and when you go out in the wild, to take a good booster pack, or a spare stock battery in a plastic battery box. A whole second battery is better insurance against total battery disaster.

I bought the 34 series battery and it fit’s without any modification. The 34 series puts out more amperage than the 58 series.

You can look at the different dimensions of batteries at Excide's site.
http://www.exidetechnologies.com/pdf/Exide_2002_catalog.PDF

It has lots of good information.

Cox89XJ said:

I bought the 34 series battery and it fit’s without any modification. The 34 series puts out more amperage than the 58 series.

Click to expand...

Thanks for that info ... the 34 generally holds about 15-55% more than the 58 group. My main question was will it fit. I think that height is the main concern, but since the pos. terminal is toward the middle of the engine compartment, it sould be fine, since the hood space is a little higher there.

8991XJ: Thanks for the link ... that is a very thorough guide to battery sizes, and more. The Interstate battery site is set up to make it a little harder to get the info.

In general, my thinking is this: A battery is a device to store electricity. If you are measuring stored energy in CCAs, why buy a battery that stores 540 CCAs if you can buy a battery for the same price that stores 700 or more? This probably won't make a huge difference in your vehicle, but it's a definite improvement.

For example, if you leave your lights on for 2 hours by accident, you'll have more energy remaining in a 700 CCA battery than a 540 CCA battery. That means you'll have a better chance to start your xj without a jump. It also means that you've retained a higher percentage of the total charge in the battery, which is better for the battery's health.

I'm no expert on this subject, but I think that a 700 CCA battery will just do a better job than a 540 CCA battery: It should be more reliable and last longer. But ... I might be wrong.

There are other considerations as well -- like the thickness of the plates -- that are important factors in overall reliability in off road vehicles. GoJeep's website has some good info about that, and also on how he modified his battery tray to take a larger battery.

I’m no expert either but the cca doesn’t mean much.
I thought that once too.
The most important information is not even on the battery anymore and that’s AH or amp/hour.
The deep cycle batters list it and so do the dual purpose.
700 cca for 3 seconds or 580 cca for 3 seconds don’t mean squat when your leave lights on or need to run your Light bar with the engine off.
The AH for a standard starting only battery is about 10 AH
While the AH on a deep cycle /starting battery is 70 to 120 AH.
(Ah) means that a 120 ah battery would put out 12 v for 120 hours with a 1 amp load. Or 12 hrs with a 10 amp load.
I have left my head light on overnight and still started in the morning.

There are (or were) three ratings used commonly on batteries:

CCA - Cold Cranking Amps. This was a measurement of instantaneous power deliverable at 0*F - important, because chemical reactions slow down with temperature drops.

HCA - Hot Cranking Amps. Instantaneous power deliverable at 80*F, or thereabouts (probably higher.) Batteries don't do well a high heat, because the chemical reaction that makes power also tends to degrade the battery.

Reserve - rated in amp-hours. A measurement of how long the battery can produce a fixed power without significant voltage drop. 120Ah means that you can get 120A for one hour, 10A for 12 hours, 5A for 24 hours, or any other combination that multiples to 120Amp-hours. Similar for other ratings.

While CCA and HCA are vaguely related to each other (and largely dependent upon construction,) the "reserve" rating has little to do with the other two - and mainly has to do with plate area more than anything else. This is why larger batteries are able to have a higher reserve capacity - and why "spiral cell" (where the plates are rolled up instead of laid parallel to each other,) typically will have a higher reserve than conventional batteries. CCA and HCA have less to do with plate area, and instead with plate chemistry and electrolyte compositon (about which little can be done. Typically, it's plate construction and chemistry that matters more - sulphuric acid is sulphuric acid, and only the concentration changed.)

Of course, the HCA has long since fallen into disuse (except in some cases,) and the reserve rating is going the way of the Dodo bird - because marketing has gotten people convinced that CCA is the end-all, be-all of battery ratings. It's like hawking truck engines based upon horsepower output - while nice, I'm more interested in torque - and so should be anyone else buying a truck to actually put it to use...

Lesson? Ignore marketing hype - they know sod-all about engineering as a rule anyhow.

5-90

I agree, reserve is what you need. Of course you might assume, and it might be right, that the more CCA the battery gives, the more reserve it has too, but that's not all of it. For example, back to my ol'Merc diesels: it's not that hard to start one of these on a moderate day with an ordinary car battery. It will crank, and it will start. But it will also literally melt the innards of the battery after a while. Those cranking amps are needed for the load. I really don't know if the correct battery will also hold its voltage longer if you leave the lights on. Probably, simply because it's so big, but that's not really why the battery has to be special.

But if you leave the lights on all day, or some malfunction causes the battery to fail outright, it won't matter what the specs are. You'll be better off carrying a booster.

While were talking batteries one little nasty thing we don't hear about is the battery in the new Hybrid cars.
They still only last 3-5 years and cost 3-5 thousand dollars to replace.
Add that to the vehicle cost and you don’t save anything in the long run.

So? As long as the sheeple are convinced that hybrids "fart kittens and rainbows" while they're running, they'll sell.

Here's another concern - aren't they still lead/acid batteries? What happens if one gets hit in the battery, and all that sulphuric acid gets loose? Just a thought...

5-90

im running a duralast gold its rated like 1000 ca 880 CCA and 104 reserve and it only cost me 80 bux at autozone plus the 5 year unlimited warranty. ye iknow i could have had an optima for only 50 more but didnt have it at the time

WELL....because it is an eco-car, Mother Nature jumps in and immediately turns that evil acid in to pure spring water......lol

actually i think there built like the optimas or the might be a lithium ion type too

Just put an Optima D34 in our 89, has lotta room. Heres a link to help sizewize if you go Optima http://www.optimabatteries.com/publ...nfig/product_info/marine/technical_specs.html

dude the hybrids have been shown that it will take forever to actually reach any kind of savings after it is all paid off and blah blah blah they are still to expensive