Any JK guys running a single Group 31 battery instead of dual batteries?

[Comanche Scott]

I was looking at the stock tray, and it looks like it would take a small modification to cut away a tab, then a modification to make a hold down setup to install the Group 31.
I think the evap solenoid would need to be moved as well, depending on which group 31 battery is bought. The Diehard platinum is over 13" long, where a few of the others are a bit shorter.
I may still try this. I can always use the battery in another rig if I don't like it in the Jeep, and the battery tray is discarded with the Genesis setup any way, so it's no loss to modify.
If I do this mod, I'll probably open up the hood vents to help keep the battery cooler.

 

[Johnnyenglish]

Sorry guys. I was traveling a bunch for work and not checking the forum. My battery/solar setup works great. The fridge was able to run for four days without starting the Jeep with no issues. It's very simple and effective.

 

[Johnnyenglish]

You are correct the exam solenoid has to be moved and the small tab cut. Other than that it's super simple.

 

[vtsoundman]

Any pics of the mod? I routinely did this on my boats...small starting battery and fewer large batteries. Routinely saw longer life and less evap (true flooded cells) so the batteries had a much easier go of it. The chemistry supports this approach with scaling, outgassing etc.

I was the lead battery research engineer at a major UPS company for several years - only reason we used smaller batteries was cost. For customers looking for the longest life, always used the the fewest/largest single battery possible.

 

[JCDriller]

+1 A photo of everything would be much appreciated!

 

[Comanche Scott]

Sorry guys. I was traveling a bunch for work and not checking the forum. My battery/solar setup works great. The fridge was able to run for four days without starting the Jeep with no issues. It's very simple and effective.

Hey John,

good to see you back. Hope all is well. :beer:

 

[vtsoundman]

+1 A photo of everything would be much appreciated!

Would really like to see a pic of the battery mounted up!

 

[Comanche Scott]

Would really like to see a pic of the battery mounted up!

If it's helpful, I did a write up on installing the Group 31M Odyssey starting here at post 270, and going over the next page or two.
http://www.expeditionportal.com/forum/threads/129035-2014-JKURX-quot-Bought-Not-Built-quot-er-build-thread?p=2015577#post2015577

 

[Comanche Scott]

Capability of JK to recharge a 31M AGM battery on a daily basis.

Ran a discharge/charge test over the week.
Depleted the battery to 60% Depth of Charge (approximately 12.4V for this battery).
Then fired up the Jeep to see how it would do recharging the battery.
Initial start at idle showed 30A at about 14.52V to 14.54V. Holding the engine at 2,000rpm did not change voltage or amperage.

So I went for an hours drive, city (30% time), country roads (40% time) and freeway(30% time), to see how it would recharge.
Came home, turned off engine, and left the lights on for about 3 minutes to remove any surface static charge.
Battery showed 13.0V at 100*F. Correcting for temperature, that relates to approximately 12.8V. So basically full charge.
I was monitoring system voltage along the drive, which ranged from 14.3V to 14.7V. Mostly averaged between 14.3V to 14.5V.

While certainly not a "scientific experiment" with controls and repeat-ability, it does confirm my confidence in the Jeeps ability to maintain the battery as long as I don't do stupid things.
Hope this helps someone else considering this swap. :beer:

(Note in the picture below the amp gauge shows 25A, but is 5A off when compared to a very accurate shunt meter. So Alternator output to battery was an actual 30A.)

 

[James Pierce]

If it's helpful, I did a write up on installing the Group 31M Odyssey starting here at post 270, and going over the next page or two.
http://www.expeditionportal.com/forum/threads/129035-2014-JKURX-quot-Bought-Not-Built-quot-er-build-thread?p=2015577#post2015577

Looks good Scott. I've been running a 31m since early 2014 with zero issues over the last 2 years. Brandy has a 2 mile commute and we haven't noticed any charging issues even in such a short cycle.

 

[Comanche Scott]

Thanks James,

That means a lot.
This Jeep gets such little / intermittent use, that your confirmation is definitely more valuable! :beer:
I think yours and Johnyenglish' input is more relevant for the average Jeep person for sure.

 

[James Pierce]

I would add that I cary a Micro Start as a back up which I've not had to use. It's just cheap peace of mind and is easy to use on others who need a jump. Our trailer also has 2 31m's and is present on most of our adventures. Being a trailer guy dual batteries were't really a necessity. I could easily swap in a battery from the trailer or give myself a jump should the spod for some reason drained the battery. The 31m is more than capable of handling all of my winching needs. My biggest issue with most of the Dual battery systems, aside from adding complexity, is that they require you to hack up the inner plastic fender / battery tray and replace it with a somewhat open metal framework. Those that I've seen first hand leave a lot of openings for mud to enter the engine and battery compartment.

 

[Tombstone17]

Has anyone tried dual 6 volt cart batteries in series, it would be a deep cycle

 

[Vanhalo]

Started thinking about running one large group 31 AGM, rather than a dual battery setup. Then just keep one of the new Lithium Ion emergency jump kits with the vehicle.
.
Just wondering if anyone else is doing this? If so, what did you do for a battery tray and hold down?
Thanks for the input! ?

DieHard Platinum Battery for a 2012-Up Jeep JK Wrangler – Project-JK.com

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