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Topic Review (Newest First)
11-27-2013 12:47 PM
foo.c I've been having this issue with my reverse lights staying on.

The dealership said the insulation on the wire which goes to the reverse switch in the trans had rubbed through. They said it rubbed on the aftermarket battery tray or a bracket that was part of the tray. (I'm going to see if they can show me so that I can add some extra protection there.)

Keep an eye on this.
06-03-2013 11:51 AM
foo.c The battery light is coming on in the mornings now. If I restart, it seems to go away until the next time it sits a while. I think it's these batteries. I have had terrible luck with Optimas, and these are of unknown age. (They came with a trailer I bought.)

I'm going to replace the primary battery with my OEM battery and see if it goes away. I'll probably get a Diehard Platinum as a replacement.
02-25-2013 10:15 AM
foo.c
Quote:
Originally Posted by LBrito View Post
My Jeep is currently in for a new head. No issues with the dual batteries.
That's good to hear, not that your Jeep is in the shop, but that you didn't have any warranty trouble because of the dual batteries.
02-25-2013 05:30 AM
LBrito
Quote:
Originally Posted by scottmphoto View Post
Curious....what do installs like this (dual batts, fuse blocks, etc) do to your warranty?
Nothing. It is the same as getting a single giant battery and stuffing it in there as far as the rest of the Jeep is concerned. As long as installed properly, it won't be an issue. And by properly, I mean, they are configured in parallel not in series, and all the wiring is secure and not shorting out or anything. If it shorts, you'll be able to tell. If you accidentally set it up for 24V, you'll be able to tell. A bad install is easy to spot, and they will be able to show you where and how it caused a problem (e.g. show you a shorted or damaged wire). If you have a genuine electrical problem, they will track it down and fix it. The duals are also no issue for the big 160 amp alternator.
02-25-2013 05:21 AM
LBrito
Quote:
Originally Posted by foo.c View Post
If I get the dreaded Pentastar dead head, I will fight with them if I have too. The issue is so well documented that I can't see them getting out of it.

If I get an electrical problem, I'm pretty sure I'll be on the hook for it.
My Jeep is currently in for a new head. No issues with the dual batteries.

Unless your dealer service guy is a complete idiot, electrical problems will never be attributed to your dual battery setup either unless they can be directly correlated. For example, if you damaged some wires to the TIPM or things like that, but really, 1 or 2 batteries still only provides 12 Volts, per spec, just has more reserve capacity. Any real electrical problem would be detectable by them, and repairable. You'll be fine, no need to worry about it. At worse, you can remove all the isolation equipment and install a single battery and show that the issue still exists.
02-10-2013 02:23 PM
foo.c
Quote:
Originally Posted by Vin View Post
Thank you.
Here's the link. I was on my phone earlier and couldn't look for it.
02-10-2013 02:21 PM
foo.c
Quote:
Originally Posted by scottmphoto View Post
Curious....what do installs like this (dual batts, fuse blocks, etc) do to your warranty?
If I get the dreaded Pentastar dead head, I will fight with them if I have too. The issue is so well documented that I can't see them getting out of it.

If I get an electrical problem, I'm pretty sure I'll be on the hook for it.
02-10-2013 01:59 PM
Vin
Quote:
Originally Posted by foo.c View Post
Perfect Switch Power Gate 200 amp dual rectifier.
Thank you.
02-10-2013 01:16 PM
scottmphoto Curious....what do installs like this (dual batts, fuse blocks, etc) do to your warranty?
02-10-2013 12:42 PM
foo.c
Quote:
Originally Posted by Vin

Details, please. What isolator did you use?
Perfect Switch Power Gate 200 amp dual rectifier.
02-10-2013 08:22 AM
Vin
Quote:
Originally Posted by foo.c View Post
I installed mine this morning. Kind of a rat's nest but it works.
Details, please. What isolator did you use?
02-09-2013 05:30 PM
1Topp
02-09-2013 04:44 PM
foo.c I installed mine this morning. Kind of a rat's nest but it works.
10-28-2012 01:57 AM
Vin Welcome back, LBrito. I was wondering what happened to you.
10-27-2012 10:18 PM
SilverSport Thanks for the pics!
10-27-2012 09:43 PM
LBrito
Quote:
Originally Posted by Grand Umpah View Post
Did the digital multimeter come with the isolater system or was this a part your sourced independently? If the latter, where and a part number, please?
It strikes me as a good add-on even with a 1-battery system if you're putting a hard load on the alternator (during winching, etc.).
Another post asked if you were going to add a more heavy duty alternator. Is this potentially needed given the extra load that 2 batteries might require, or does the isolator manage the load such that the required amps don't exceed what the alternator can deliver.
Regarding the voltmeter, I sourced the part independently. I got mine from Amazon: Amazon.com: Stinger SVMB Voltage Gauge - Blue Display: Car Electronics
They also come in red.
The isolator is pretty much passive, all it really does is control when the batteries are connected together, and when they are isolated, based on conditions. But, the batteries do have some reserve, so if you exceed the alternator output, then you'll start to tap into the battery reserve.

I responded to the question on the alternator via PM, forgot I never updated this post. Here is a copy/paste of my response:

Forgot to respond to your question on the thread, but no, I don't think a higher output alternator is needed. At idle, the stock 160amp puts out about 100 amps, I think full capacity starts at around 1500rpm. I'll have to measure the current at higher RPM, but, that's plenty of juice. It will charge my fully drained optima in about 30 minutes. Both would be topped off within the hour.

The way the isolator works, it charges the main battery first for a bit, then connects the aux battery, so it doesn't put an unneeded strain on your alternator (not that it couldn't handle charging both, but it might be a strain if you're running a full set of off-road lights, say 4 x 100W, which would draw about 40 amps, plus a bunch of other junk. But, if you're just running normal vehicle stuff, you can overwrite the wait period to charge up the main and start charging them both up together by pressing the Boost switch on the isolator, and it will pair them both to the alternator. The alternator will just see it as a higher capacity battery.

I looked at the offerings for upgraded alternators, and they're really not worth it unless you plan to do a lot of winching. When you think about it, a winch will draw about 200 amps at load, and if 150amps from the alternator go to the winch, then the other 50 amps have to come from batteries. If you have a Optima D34, that's a 55 Amp Hour battery. That means it can deliver 55 amps continuously for 1 hour. So, you can winch, non-stop, for 1 hour, before it dies. I doubt anyone would exceed that. So, with duals, you can extend that to 2 hours max (you probably want to limit it to 1.5 hour, to ensure you can still start the vehicle). This is also talking continuous operation, any time you stop winching, that alternator will keep putting out the current that will charge your batteries back up a bit.

So, something like a Mean Green 200 Amp alternator is still a bit overkill, it makes more sense with a single battery though, instead of doing duals. Cause then you can recharge that battery in about 20 minutes, and the extra juice you'd get from a second battery for winching can be somewhat replaced by a higher output alternator.

But, I don't run all the high current items at once, that may be different for someone who runs 4 x 100W off road lights (40 A), plus 100W Ham radio (10A) going + other stuff, then it might make sense to upgrade so that you don't have to wait so long to recharge the batteries if all those things are running.

Jeep got it right when they chose 160Amps, plenty of juice for most folks. Now, if money wasn't an object, then I'd upgrade. But, because of the way that the engine handles all the electronic, we are limited in our choices of alternators, and the cost of a small upgrade is pretty ridiculous for not so much benefit.
10-27-2012 09:33 PM
LBrito
Quote:
Originally Posted by SilverSport View Post
I understand this mod is classified top secret, but if you get a chance would you mind posting pics of the circuit breaker, fuse box, etc?
Sorry for the late follow up. Didn't get a chance to work on the Jeep till just yesterday.

Here is a photo of my placement of the Blue Sea Systems Fuse Block:

I bought mine from Amazon: Amazon.com: Blue Sea Systems Fuse Block Ato 6 Circuit with Ground: Sports & Outdoors

In this picture you can see how I mounted it using an L-bracket.

And you can also see the 4 AWG cable that feeds into it. Doing some re-positioning of accessories at the moment, so only 1 item is connected to the bus in the picture.

That wire runs over to the other side of the engine bay, and I used the breaker to protect it. Here is a picture of where I located it. There was already a stud there, and so I flattened an L-bracket and used that bolt to secure it to the side of the jeep, and then used other holes in the L-bracket to secure the circuit breaker to it.

Got that from Amazon also: Bussmann Hi-Amp Circuit Breaker - 150 Amps : Amazon.com : Automotive

I just used a 50amp version of one of those: Amazon.com: Bussmann Hi-Amp Circuit Breaker - 50 Amps: Automotive
And ran an 8 AWG wire to the rear of the Jeep. This will feed the rear mounted ARB fridge, which was using the factory plug that was coming from the main battery, with a dedicated charge port from the aux battery. It will also go to additional 12V outlets. I'm running it to the cubby in the trunk, and there I will use a relay/switch/fuse combo to run a 10AWG cable to the trailer for additional accessories. The relay and switch will allow me to terminate trailer power when the trailer is not there, so there isn't any issue with a live wire back there. That's a work in progress, since I am waiting on some water proof connectors and some lots of other things. But, ran the wire using the foam plug method on the passenger side as shown here:

In case anyone was wondering, this is just like the driver side, and feeds into the engine through here:

Easy run, straight to the batteries. Then I fed it through the sills all the way to the rear of the vehicle.
10-27-2012 09:02 PM
LBrito
Quote:
Originally Posted by MountainOffroad View Post
LBrito,
Thanks for your great write up. Here at Mountain Off Road we listen to our customers and their critiques. We have made is simple change to the strap location by lowering the slot down below the top of the battery the strap will now synch both batteries down tight. Thanks for everyone interest in our Dual Battery Tray for 2012 JK. Happy Wheelin!!!!
Glad to hear! Great build quality on the tray!
10-27-2012 08:44 PM
Grand Umpah Did the digital multimeter come with the isolater system or was this a part your sourced independently? If the latter, where and a part number, please?
It strikes me as a good add-on even with a 1-battery system if you're putting a hard load on the alternator (during winching, etc.).
Another post asked if you were going to add a more heavy duty alternator. Is this potentially needed given the extra load that 2 batteries might require, or does the isolator manage the load such that the required amps don't exceed what the alternator can deliver.
10-27-2012 08:28 PM
LBrito
Quote:
Originally Posted by Moabite View Post
I'll look into the Isolator you mentioned. Sounds like it might have been easier to install than the one I used from Hellroaring Technologies. If I remember right, I had to run a wire to the alternator also.
I definitely recommend it. In general, a smart isolator, either MOSFET or intelligent solenoid based is a good idea. There are several Diode based (or silicone controlled rectifier) isolators, and they tend to have the typical 0.7V forward voltage drop of a diode. This tends to have a negative effect on charging batteries, and often leads to them not being fully topped off. I've seen other manufacturers with lower forward voltage drops of around 0.3V, but that's still not ideal. I saw a couple of these at the local auto parts chains for around $40. I recommend staying away from those.

I chose the Cole Hersee 48530 because it was rated for 200 Amp Continuous current, some others rate by peak current, which is cheating. I also like that the Quiescent Current (how much current the actual devices uses when its doing nothing) was very low, 5mA typical, 8mA max. I also really liked that they are SAE rated for protection against RF, EMI (Electromagnetic interference is an important consideration when you will sit this thing next to some high current winch cables and all sorts of clicking power loads), Shock (off road use can shock this unit quite often), Vibration (again, off road it will be subject to this frequently), Thermal Shock (this one is important if you see snow or really cold weather. It can go from freezing to very hot in a short amount of time sitting in the engine bay and its nice to know that this thing is rated to survive such a thermal shock). Oh, an IP65 ingress rating, so its not just waterproof, you can hit it with a pressure washer if you want (don't recommend that). What else? its made in the USA, and I'm probably forgetting a lot more.

As far as the alternator goes, in this case, it does not get separated since it can do an inline sense. So, the alternator and starter cable stay in their factory location tied to the positive battery post . So, yeah, if you had to install one that separated them, this will be a breeze in comparison.
10-27-2012 07:58 PM
LBrito
Quote:
Originally Posted by Hilldweller View Post
I trust Blue Sea switch materials; used that on my Conqueror trailer.

What kind of trailer do you have?

BTW, I run 3 huge batteries when I'm overlanding. The big main and two remote Optima D31Ms. I carry a genny, just in case, but the PW has always been able to charge things back up.
I just love my ARB fridge...
I have an m416 trailer. It's a fun project, a lot more work than I anticipated it would be. I appreciate the commercial off-road trailers and their pricing now. DIY projects end up costing almost the same, more when you factor your own time costs. I've seen your trailer in a few threads. It's an awesome machine.
10-25-2012 07:46 AM
mackdj1
10-25-2012 07:40 AM
MountainOffroad LBrito,
Thanks for your great write up. Here at Mountain Off Road we listen to our customers and their critiques. We have made is simple change to the strap location by lowering the slot down below the top of the battery the strap will now synch both batteries down tight. Thanks for everyone interest in our Dual Battery Tray for 2012 JK. Happy Wheelin!!!!
10-04-2012 10:58 AM
Moabite Great post. I installed dual batteries in my 03 Rubicon shortly after picking it up from the dealership. The spare battery has saved me several times. My Jeep often sits for weeks at a time without being started...and though I usually have a solar trickle charger on it, sometimes the main battery is run down. On modern vehicles, something is always using power even when the vehicle is off. I also have a fridge/freezer mounted in it, and dual batteries make it so that I can leave it running in the wilderness without having to worry about being stranded out there with nothing but a tray of ice.

The 03 tray was made by Mean Green. Since the batteries had to be mounted on their sides, I had to use Optimas. One nice thing about the Mountain Off-Road tray is that the batteries are mounted upright and you can use the OEM battery as the main or backup. The new Jeep will be here in a few weeks. One of the first things I plan to do is install dual batteries.


I'll look into the Isolator you mentioned. Sounds like it might have been easier to install than the one I used from Hellroaring Technologies. If I remember right, I had to run a wire to the alternator also.
10-04-2012 10:06 AM
Hilldweller I trust Blue Sea switch materials; used that on my Conqueror trailer.

What kind of trailer do you have?

BTW, I run 3 huge batteries when I'm overlanding. The big main and two remote Optima D31Ms. I carry a genny, just in case, but the PW has always been able to charge things back up.
I just love my ARB fridge...
10-04-2012 08:52 AM
Vin Thanks, LB. That's what I thought you said, but the switch terminology always gets me. You should have seen when I tried asking the OTRATHW guy about the switch I used for the dual battery set. After he nicely went through a very detailed explaination as to how the switch worked, I was like, "I just need it to work with my Smart Isolator to connect the batteries, and I need an LED that will light when the batteries are connected and fit in an sPod."
10-04-2012 04:44 AM
LBrito
Quote:
Originally Posted by SilverSport View Post
I understand this mod is classified top secret, but if you get a chance would you mind posting pics of the circuit breaker, fuse box, etc?
No classified data here. I will post pictures as soon as I get a chance. The Jeep is spending the night at the dealer getting serviced, and we're taking a trip Friday - Monday, so I might not get to it till Tuesday or so. But, meanwhile, I used this:
Bussmann Hi-Amp Circuit Breaker - 150 Amps : Amazon.com : Automotive for a circuit breaker, 150 amp Bussman. In the picture on my post that shows the isolator on the batteries, the big red cable at the far left slides right onto the side of the batteries. That Bussman breaker is mounted to the side of the Jeep there and that cable connects to one side of it. The other side of the breaker has a big cable that I routed along with the factory wires, so its no longer visible, but it runs along the top with that wire loom that runs on the top of the fire wall, all the way to the other side of the Jeep where there is a lot more space. I made a little bracket to hold the Blue Sea Systems Fuse Box in place. It is this one: Amazon.com: Blue Sea Systems Fuse Block Ato 6 Circuit with Ground: Sports & Outdoors
10-04-2012 04:25 AM
LBrito
Quote:
Originally Posted by Vin View Post
Could you explain this in "amature weekend wrench turner" terms? I think you were in my thread when I asked about 2 analog voltmeters in an A pillar mount. Well the A pillar crapped out, so I was thinkning about a Rugged Ridge A pillar switch panel, and the very same voltmeter you used. I was going to use 2 taking up two spots each of the 4 switch A pillar mount, but I was wondering if the voltmeters stay on all the time, or can you rig it that they only light up with the ignition.
This voltmeter has 3 wires:
1: Voltmeter Power
2: Positive side of measuring load (Battery +)
3: Negative side of measuring load (Battery -)

So, yes, you can wire it so that it comes on only with the ignition if you connect the Voltmeter power to an ignition hot source. I personally like to keep it off, and only turn it on when I want to check on things or when I'd like to be aware of it like on a trip. But, normally, I can quickly switch it on and check that the alternator is putting out 14+ volts (meaning its healthy), and toggle between the batteries, if they're both at 14+, both are charging. If only 1 is at 14, the I know one is isolated, if both are at 12, then the vehicle better be off, or the alternator is not working properly. But, really, determining isolation comes from the status LED from the isolator.

Anyway, I digressed there....back to business.

In my case, I used the DPDT switch, which has 6 terminals, and 3 possible states, its hard to put in words, so I'll draw a picture. But, basically, the switch allows you to connect 2 different sets of cables to a common terminal pair (in this case, the + and - measurement leads of the voltmeter). The 2 different sets of cables you want to connect are the +/- of the Main battery, and the +/- of the Aux battery. And the center position on the switch, leaves the voltmeter connected to nothing (off in my case).

The key difference in my case is that I tied the units power source to the + side of the measurement load (cable 1 and 2 are connected together), so basically, when you are measuring one of the batteries, that battery is also powering the device itself, and as a result, if you are not measuring something, it will be off. Now, if I had used the ignition switch to make it come on with the ignition, this wouldn't work out, because the center position would still leave the device on, but with nothing being measured, so it would show --.

Now, a picture:


This shows how the switch works, and how I wired it to measure both batteries only when I switch it up, or down, for main and aux respectively.

The green line shows which terminals on the switch are connected together at each of the 3 configurations. The first being Center, which is the OFF position in my case, or no wires connected to the voltmeter (sorry, I drew DMM for Digital Multimeter, but this is just a DVM). So, in center position, no green lines, none of the terminals are connected together.

Now, when you go to the Up, or Top, position, you can see the green lines connect the + on the AUX with the + on the DMM, and the - on the AUX, with the - on the DMM. Also, not shown, but implied, the + and the DMM power lead are combined, so when you switch it upward, the unit turns on and makes the measurement. So, now you can measure your aux battery. When you're done, you can switch the switch back to the middle position, and the DMM disconnects from that battery and shuts off.

Next, you do the same, but push the switch to the down position. You can see that in that position, the MAIN + is connected to the DMM +, and the MAIN - is connected to the DMM -, so again, it powers on, and measures the main battery.

So, ultimately, the switch just lets you connect the +/- of the meter to the +/- of both batteries by just toggling between them. So, you can use 1 meter to measure both only when you want.

It sounds like you are interested in using 2 meters, and have them on at all times that the vehicle is on. In your case, you don't even need a switch, since 1 will go to the main battery, one to the aux.
The first Voltmeter, you connect the 1) cable, unit power, to an ignition source (you can splice in to something, its low power). Then, this meter will come on with the ignition. Then, you would just connect the other two cables + and - to the Main battery positive and negative. So now anytime you turn on the vehicle, you will get the battery voltage.
The same thing with the 2nd Voltmeter, you connect it to that same ignition source, and it will also turn on with the vehicle. For this one, you will connect the 2 remaining cables to the positive and negative of the AUX battery (negative is common to both batteries, which they both end up tied to the vehicle chasis by the ground strap that comes from the alternator cable, so all those negative leads can go straight to any ground point on the vehicle). Now, you'll get a reading for the aux battery on that second meter when the vehicle is powered on.

Does that make sense, I think I went off on too many tangents. Let me know if you need a better picture or if you were thinking a different application.
10-04-2012 12:08 AM
Vin
Quote:
Originally Posted by LBrito View Post
This is what my internal monitoring system looks like:


I basically used a double pole double throw with center off switch to wire the batteries to a digital multimeter (this one has compensation functions, so you can dial in an accurate reading using a potentiometer). The boost switch is there, and at the time of this picture, the status LED was not in.
Could you explain this in "amature weekend wrench turner" terms? I think you were in my thread when I asked about 2 analog voltmeters in an A pillar mount. Well the A pillar crapped out, so I was thinkning about a Rugged Ridge A pillar switch panel, and the very same voltmeter you used. I was going to use 2 taking up two spots each of the 4 switch A pillar mount, but I was wondering if the voltmeters stay on all the time, or can you rig it that they only light up with the ignition.
10-03-2012 11:50 PM
SilverSport I understand this mod is classified top secret, but if you get a chance would you mind posting pics of the circuit breaker, fuse box, etc?
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