Dual batteries

At what point do you need to set up a dual battery system. I have my winch power inverter all other car electronics on a battery now. But if I add additional lights frig will my charging system handle it all ?
 

HAFICON

Adventurer
At what point do you need to set up a dual battery system. I have my winch power inverter all other car electronics on a battery now. But if I add additional lights frig will my charging system handle it all ?


Guess the real answer is when you are ready for it. It is not a cheap up grade, benefits are high really is no down fall except the cost. For me it is a great system, great back up. I spend as much time as I can outside the reach of AAA. Having the 2nd battery normally isolated is a nice to have. Only needed it once in 3 years cause I left the key on in a rush going into work. Came back 5 days later to dead battery. Yes I could have gotten a quick jump but simply pressed a button and paralleled batteries and started the Jeep.
 

rubicon91

Explorer
I got a dual battery setup when I was tired of my ARB 50qt getting shut off after a day camping by my stock battery. Granted I could have gone solar or something else to manage it but I had the funds and wanted to not have another item to mess with at camp so I got the Genesis Dual battery tray and 2 yellow tops. Been about 18 months now and there is not a day that goes by that I regret buying it. But like others above has posted it is not a cheap ticket item. To each their own. Is my dual battery setup overkill for just running the fridge at this time. Definitely will I care when I am out camping this upcoming weekend and drinking a cold beer and cooking some nice steak that came out of the 50qt? Not one bit :sombrero:
 

e60ral

2016 4Runner Trail w/KDSS
At what point do you need to set up a dual battery system. I have my winch power inverter all other car electronics on a battery now. But if I add additional lights frig will my charging system handle it all ?

To further clarify what was said above, while your car is running the addition of a second battery will have nothing to do with if your charging system can handle additional lights and fridge (winching is a bit different, as mentioned). What a second battery will do is allow you to run those lights and fridge for a longer time without the vehicle running. If your charging system can't keep up a second battery won't help, you need to upgrade your alternator.

I just use a single 31m battery, I don't even deep cycle it and I have enough ah capacity to run my fridge overnight with daily driving. It really just depends on your specific need if its worth it.
 

rubicon91

Explorer
If your charging system can't keep up a second battery won't help, you need to upgrade your alternator.

Thats the wonderful part of the Genesis Dual Battery tray and all that it comes with for Jeeps. There is no need to upgrade your alternator. Mine has the 200 amp isolater. Here is what it says on Genesis website
Isolator Option:
Technically speaking, the isolator rating should match the alternator output rating. In real world application, the actual output of the alternator is much lower than the published rating, so the 85 amp isolator is plenty sufficient for most Jeep owners. Some Jeep owners like to do everything overkill just for peace of mind, so there's no downside to going with the upgraded version.
Standard 85 amp - suitable for most general purpose uses, including Jeeps with a winch, lights, CB, etc.
Upgraded 200 amp - highly recommended for Jeeps with multiple high amp draw accessories such as big stereo systems or lots of electrical components. Required if using an aftermarket high output alternator.
 

e60ral

2016 4Runner Trail w/KDSS
If your alternator is sufficient I'm not sure why upgrading it would be required for any dual battery kit
 

HAFICON

Adventurer
IMG_3069.JPG

Well if all else fails it looks cool. Built my own set up, like I said out of 3 years I only needed it to bail me out once and it worked great. Nice to know when I am miles from civilization I don't have too worry about a dead battery but from that persoective should I carry an extra starter, alternator, belt..... No.. Dual batteries are a nice to have, they help but one single HD Battery would probably be sufficient. In the frigid winter bordering negative temps the 2nd battery does make starting easier. This extra amps are nice.. Paralleled I get about 2000 cold cranking amps.
 

ratled

Adventurer
I have mine for the fridge to run longer without running the motor. I also have it for winching. If you kill your motor,- water, roll over etc - and can't start the motor the dual battery system will be worth every penny to get you to a safe place to sort out whatever emergency you had and not compound it.

ratled
 

homeguy

Observer
I installed a Genesis Dual battery kit for my JKU. It works flawlessly and isolates everything you have connected to the second battery not the starting battery My battery light never comes on now after I use my winch and camping, I have a ARB 50 qt fridge that is always connected.


Sent from my iPhone using Tapatalk Pro
 

vtsoundman

OverAnalyzer
I just installed a single larger battery...it is an Sams Club AGM Group 31 105ah. Time will tell how it works out...but considering I was running my two doemtics off the stock sized group 34 agm, it should be a hell of an improvement.

I have an amp meter on the alternator and it hits 140amps often, and occasionally hit 160a - the full stock rating.

My reasoning : Dual batteries actually yields 1/4 of the total usable capacity of the two batteries (if leaving the starter battery isolated). I use an lithium jump starter for emergencies...so far it worked great on other's rigs. Also, the CCA on a big group 31 is more than sufficient for the little V6 even at 50% SOC.

At the same time, I installed the single big battery in my 07...a 2nd 100ah sealed agm went under the 40 part of the rear bench. It is charged by a CTEK dual input (solar/alternator)...reason : we are doing more base style camping where the Jeep doesn't run very much. At Expo west, the Jeep sat quite a bit...the whole system worked great. I had 150w of portable solar.

I have a an Aux load bypass relay that transfers the Aux battery loads to the main system (alternator). Thus facilitates rapid recharging of the Aux battery. There is 2nd relay that allows me to connect the CTEK solar charger to the main starter battery if it needs to be topped up.

I used a JSS battery tray and had to do quite a bit of modifying the tray...just to get the tray into the Jeep. The quality and fit left much to be desired. Ultimately, I made it work...it took far longer than it should have...granted the tray is not made for a single group 31, but the damn tray needed a ton of trimming and filing so it wouldn't hit the fender liner. Ill have to tear the whole thing out again as the tray hits the top of the shock mount.

Realized I didn't answer your question - simply add up the expected amp hours you'd draw over a given period before recharging the battery. Expect the Jeep JK charging system to reach 70-80 SOC pretty quickly (from 50) - especially if lights, A/C, seat heaters, etc are off...the last bits will take a while. My stock alternator delivers about 50-75amp (measured) at idle easily...I don't recall how much the Jeep may consume on its own...I think its around 20a or so on its own. It may do more - I didnt load test it as I was pressed for time.

For most fridges, start with a 20ah/day baseline. Add another 20-30% if it's hot and you're in / out of it frequently.

sent via the cone of silence
 
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Comanche Scott

Expedition Leader
Single large battery install

I did the same thing a little over a year ago, for the same reasons.
I've been very happy with the results. Battery (Odyssey 31M) has performed excellent running a 65qt Dual Zone Dometic.

I used the stock tray after modifying it a bit.
Info on the install starts here:
http://forum.expeditionportal.com/t...-Bought-Not-Built-quot-er-build-thread/page27

If I was to do it over, the only things I'd do different is to use better circuit breakers (had one fail due to heat), insulate the bottom and engine side of the battery box, and vent the outside of the box. Due to the cat sitting right under the battery tray, the whole battery gets very hot. That will eventually ruin the battery.
One of these days, when I get a "Round To-It" I'll pull the battery and get that done... ;)
 

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vtsoundman

OverAnalyzer
I did the same thing a little over a year ago, for the same reasons.
I've been very happy with the results. Battery (Odyssey 31M) has performed excellent running a 65qt Dual Zone Dometic.

I used the stock tray after modifying it a bit.
Info on the install starts here:
http://forum.expeditionportal.com/t...-Bought-Not-Built-quot-er-build-thread/page27

If I was to do it over, the only things I'd do different is to use better circuit breakers (had one fail due to heat), insulate the bottom and engine side of the battery box, and vent the outside of the box. Due to the cat sitting right under the battery tray, the whole battery gets very hot. That will eventually ruin the battery.
One of these days, when I get a "Round To-It" I'll pull the battery and get that done... ;)
The 2012 and newer have a different battery tray - would have made it so much easier. I had to relocate the TIPM fwd to get a group 31 to fit. I use blue sea breakers on top of battery similar to your setup and a blue sea fuse panel. The panel runs high current accessories that need to be live all the time (headlights, one of my ham radios, the rear cig lighter power port, the main inverter, and a winch power relay)...

I'll post some photos later...

sent via the cone of silence
 

Comanche Scott

Expedition Leader
Does anyone know of a replacement battery tray for the Jeep JK which fits a larger batter?
I "think" the M.O.R.E tray may fit a large battery.
It might be worth contacting them.

The stock battery tray of your 3016 with just a bit of work will work, as well.
 

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