DUAL BATTERY SYSTEMS? Feedback / Reviews?

[swampflyer]

“Nikones”. I Installed the Genesis and updated to gen 3 on my 20 JLR also the g screen and full river batteries. Very satisfied and works as advertised. Just do it. You wil be glad you did. I also use the Noco gen pro 10 x charger/trickle. I mounted it on top of the fuse box and leave it plugged in when not being driven. I don’t use self start. Hate it. Just push the button when you start. It’s like doing checks in my airplane prior to flight. Make sure you completely charge your batteries prior to install. I charged each one over night. I did all this myself following the video from Shane. If I can do it you can too.

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[Nokones]

Hey Kenny:

In the second picture you linked I see not one, but two cables connected to the negative post of the main battery.

Normally *from the factory* this is a telltale sign of the presence of an Aux battery. One of those cables, always present, connects to the body ground on the passenger's front fender. The other has, as its distal end the unseen negative post of the Aux battery.

But that said, I wonder if you have used that second connection point, absent from the factory, for one of your aftermarket appliances.

Behind your battery is that black box called the Power Distribution Center (PDC): your intelligent fuse box. If you pinch its cover clips and lift it up it will look something like the following picture inside. The two terminals I have circled in my picture below are N1 (closer to the bottom of the picture) and next to it N2. Unlike in this picture do they have a metal jumper connecting the two terminals? If so, I would think that despite the appearance of your battery's negative post with its two cables, that you may not have an Aux battery.

 

[Slate]

I have it. I got it after my main drained down and caused all kinds of problems. I felt kind of dumb on why it drained down, and I have a 4XE so I had assumed that the 12V would never run out with that big ass battery, but it doesn't work like that.

I also have winch, lights, compressor under the passenger seat and I have a Dometic Fridge. So it seemed to fit my use case. I am not going to lie to you and tell you I do all kinds of over-landing or something, but I like the peace of mind and hell, if tricking out your rig wasn't so much fun, we would never do it right?

I think its easy to throw parts at a problem and spend more money than necessary, but I like it and don't worry about my 12V anymore and I know I can run my fridge.
We often hit the "big city" over an hour a way to go to Costco, Trader Joe's etc., and I love having my fridge in the back keep things frozen and I love not worrying about running down my battery while we shop at other places, eat dinner, etc. I do have a Jackery as well - so certainly a "belt-and-suspenders" kind of thing.

 

[Nokones]

I have it. I got it after my main drained down and caused all kinds of problems. I felt kind of dumb on why it drained down, and I have a 4XE so I had assumed that the 12V would never run out with that big ass battery, but it doesn't work like that.

I also have winch, lights, compressor under the passenger seat and I have a Dometic Fridge. So it seemed to fit my use case. I am not going to lie to you and tell you I do all kinds of over-landing or something, but I like the peace of mind and hell, if tricking out your rig wasn't so much fun, we would never do it right?

I think its easy to throw parts at a problem and spend more money than necessary, but I like it and don't worry about my 12V anymore and I know I can run my fridge.
We often hit the "big city" over an hour a way to go to Costco, Trader Joe's etc., and I love having my fridge in the back keep things frozen and I love not worrying about running down my battery while we shop at other places, eat dinner, etc. I do have a Jackery as well - so certainly a "belt-and-suspenders" kind of thing.

And it is another gadget to have on the Jeep and hang with the kool Jeepers and their gadgets.

 

[AndySpill]

Hey again Kenny:

What I'm seeing is evidence that behind that front passenger's tire, in your engine bay and closer to the ground than top of the bay is a factory Aux battery. I say this because I do not see the jumper I described in your picture.

I would ask others to correct me if that assessment is wrong.

But lets operate under the assumption that it is correct. And if so, it opens up IMHO an entire different view of things. Here's why:

Shane of Genesis Offroad's great products will always be limited by the batteries they operate under. And the factory dual AGM battery configuration leaves much to be desired IMHO, particularly for the off-roader.

If you want to do this right, and it will involve more money and installation, I'd consider his kit that involves the installation of his dual Group 25 batteries in place of these two factory batteries.

It is rumored that Stellantis incorporated this dual battery setup to insure that the sensitive vehicle entertainment electronics would have enough power during ESS events. Against battery purists, which believe that batteries in parallel (like these) should be of equal size, chemistry, age and duty cycles, Stellantis incorporated different size AGM batteries with different duty cycles.

Barring ESS events and an instant at cold crank, these batteries' parallel connection, while providing more amp hours, allow one battery going bad to kill the other: usually here the Aux battery destroying the main. You turning off ESS does nothing to prevent that.

Most auto makers implementing ESS do it with one battery. Stellantis uses this Aux battery to run appliances during ESS events to spare the main battery for the post ESS engine crank.

 

[Nokones]

Well, I finally got around to ordering my Genesis Gen 3 Dual Battery System with the Odyssey Batteries and the Engine-On Sensor Circuit Cable. I elected to not get the G Screen because I just don't see the critical need of having it and the fact that I can't decide where is a good place to put it.

I have all my Lights, radios, and refrigerator powered by the Aux circuits which I'll leave as is. My winch and external power point for my air compressor will be the only device connected to the Secondary Battery Buss-Bar.

My Wrangler Rubi will be coming up on 2-years old this coming Spring so it will be the right time to get the itty-bitty Battery out of my Jeep before it fails and leaves me stranded on the Trail.

Also, I ordered the Odyssey 25-amp ASM/Lithium Battery Charger so I can keep my batteries properly charged up between the Trail Runs.

 

[Mguy]

My Wrangler Rubi will be coming up on 2-years old this coming Spring so it will be the right time to get the itty-bitty Battery out of my Jeep before it fails and leaves me stranded on the Trail.

Your post 7 has the manufacturer's sticker which shows your Jeep is eTorque, which means you have no alternator. JLs without alternators do not have aux batteries. Your post 17 has a photo of the high amp fuse array on the N studs, showing a connector strap between N1 and N2. This means your JL has none of the aux battery, N3, and PCR cabling. When you instal the Genesis system you can ignore steps that deal with the aux battery and it's cabling. Good luck.

 

[Nokones]

So, does that mean my Stop/Start system was being worked from my one and only battery?

 

[AndySpill]

Your post 7 has the manufacturer's sticker which shows your Jeep is eTorque, which means you have no alternator. JLs without alternators do not have aux batteries. Your post 17 has a photo of the high amp fuse array on the N studs, showing a connector strap between N1 and N2. This means your JL has none of the aux battery, N3, and PCR cabling. When you instal the Genesis system you can ignore steps that deal with the aux battery and it's cabling. Good luck.

I think I see the jumper now. I missed it on the picks originally, thrown off by the fact that the OP has two cables connected to his main battery's negative post.

My understanding was that factory Etorque looked like this:

https://www.jlwranglerforums.com/forum/threads/aux-battery-how-do-i-know.120115/post-2501518

Perhaps the OP used that opening on the negative terminal for his aftermarket stuff.

Kenny: if you have etorque than your ESS events are being energized through the 48 volt battery.

If you open the PDC (Power Distribution Center) is Circuit 42 absent a fuse? That circuit runs the PCR (Power Control Relay) that separates the two batteries in the dual AGM 12V battery JLs like the regular 3.6L and plays no role, from what I understand, in the Etorque models, hence the absence of a fuse here, as from the factory, being a tell tale sign.

 

[Nokones]

I think I see the jumper now. I missed it on the picks originally, thrown off by the fact that the OP has two cables connected to his main battery's negative post.

My understanding was that factory Etorque looked like this:

https://www.jlwranglerforums.com/forum/threads/aux-battery-how-do-i-know.120115/post-2501518

Perhaps the OP used that opening on the negative terminal for his aftermarket stuff.

Kenny: if you have etorque than your ESS events are being energized through the 48 volt battery.

If you open the PDC (Power Distribution Center) is Circuit 42 absent a fuse? That circuit runs the PCR (Power Control Relay) that separates the two batteries in the dual AGM 12V battery JLs like the regular 3.6L and plays no role, from what I understand, in the Etorque models, hence the absence of a fuse here, as from the factory, being a tell tale sign.

Yes, there is no F42

 

[mark203]

So, does that mean my Stop/Start system was being worked from my one and only battery?

Your Stop/Start system is being powered by the lithium e-torque battery.
At the end of an ESS event (restart), the DC motor-generator that replaces your alternator is used to crank the engine - this is independent of your 12v starter battery.

the "torque" in e-torque comes from the DC motor continuing to run for a bit after the vehicle starts moving again, to give you a bit of boost off the blocks while the engine comes up to speed.

It (sometimes) also kicks in to smooth out gear changes.

The charging system uses the DC motor-generator to charge the 48v lithium battery, and then your 12v starter battery is charged from that.

 

[AndySpill]

Your Stop/Start system is being powered by the lithium e-torque battery.
At the end of an ESS event (restart), the DC motor-generator that replaces your alternator is used to crank the engine - this is independent of your 12v starter battery.

the "torque" in e-torque comes from the DC motor continuing to run for a bit after the vehicle starts moving again, to give you a bit of boost off the blocks while the engine comes up to speed.

It (sometimes) also kicks in to smooth out gear changes.

The charging system uses the DC motor-generator to charge the 48v lithium battery, and then your 12v starter battery is charged from that.

Hi Mark:

Not to hijack this thread but I'm curious, on the Etorque, during ESS events, the sole 12V battery is what *directly* energizes the vehicle's appliances correct?

And I qualify the work "directly" because I was under the impression that the 48V battery can provide charge to the 12V battery, and was wondering (if you know) if such charging between the 2 batteries also occurs during ESS events when the 48V battery is itself not being charged by one of its power sources, such as the idling engine or regenerative braking?

I was also wondering what might preemptively end an ESS event before the vehicle operator takes their foot off the pedal in the Etorque? I'm guessing that the 12V battery's voltage is monitored during ESS events, not unlike the Aux battery's voltage is monitored during such events on the dual AGM battery JLs, early terminating the ESS event if that voltage drops too low.

Perhaps, if the 48V battery can replenish the 12V during ESS events, that early ESS event termination due to 12V battery voltage drops might only be a product of a bad/old 12V battery not capable of accepting (much) charge from the 48V battery.

From what I understand the DC to DC charger between the batteries in the Etorque might have some intelligence built into it such that a bad 12V battery doesn't destroy the 48V one, unlike how in the dual AGM battery JL, for example, a dying Aux battery can take out a main battery given their parallel connection, particularly while the vehicle is parked and at rest, not accepting alternator charge.

This got me thinking how maybe when the vehicle is parked that for dual AGM battery JLs the two batteries should not be connected as they, by design, are from the factory during such idle periods.

 

[Pismo61]

Using an external charger to maintain batteries is not a bad thing. It depends on the battery type and if it is a smart charger rather than a non-smart charger. Non-smart chargers will not have the proper algorithm for the health of the battery, especially batteries that are in storage more than daily used.

For the longevity of the battery, that is not used daily, a smart charger is required that will not only keep the battery charged but also condition the battery and that is where the charger's algorithm is important. A constant charge or trickle charge will ruin the battery over time. The battery needs to be exercised regularly.

I've been using smart chargers for almost 15 years and I have several batteries that are 8-10 years old and still in service with no signs of failing.

Is this considered a smart charger?amazon.com/Battery-Tender-Selectable-Lithium-Charge/dp/B07XMJDJX7/ref=sr_1_5?crid=1EMNBMNBTFM7F&dib=eyJ2IjoiMSJ9.8urFk3TaiOgYKLqkEigRQ1_Ubnxu3Wha2lG-jQ6HdPMS3oYdJroaN3hmLz3gQJrpLmKInN_gVtjcSm3yl6c51IyTQkWNo5JpxfHFBCtIjU2r4u6Ecl_KVsMd13H-Vcy8IBcyLvjio2olb4Hd4DC4_211-vutjy9gYslnJoJF0aBooKmixLSBw_qFIkoivdVAqcvDX-7wMbejNWvcQJ83NqZP8i7MrViKlLLQs_KuNRH8GbhQGfUyrOUjUoHLxTNCqUm2b1lpPNbkOg4ZjvgM7VO2IG16Js3dALZnFvqgQ6Q.CEoh-gzzdcY1pbqQpmNW6d-Fe8k_-b8KnMVc8J7Dh3k&dib_tag=se&keywords=4amp+battery+tender&qid=1732463640&sprefix=4amp+%2Caps%2C328&sr=8-5

 

[AndySpill]

Is this considered a smart charger?amazon.com/Battery-Tender-Selectable-Lithium-Charge/dp/B07XMJDJX7/ref=sr_1_5?crid=1EMNBMNBTFM7F&dib=eyJ2IjoiMSJ9.8urFk3TaiOgYKLqkEigRQ1_Ubnxu3Wha2lG-jQ6HdPMS3oYdJroaN3hmLz3gQJrpLmKInN_gVtjcSm3yl6c51IyTQkWNo5JpxfHFBCtIjU2r4u6Ecl_KVsMd13H-Vcy8IBcyLvjio2olb4Hd4DC4_211-vutjy9gYslnJoJF0aBooKmixLSBw_qFIkoivdVAqcvDX-7wMbejNWvcQJ83NqZP8i7MrViKlLLQs_KuNRH8GbhQGfUyrOUjUoHLxTNCqUm2b1lpPNbkOg4ZjvgM7VO2IG16Js3dALZnFvqgQ6Q.CEoh-gzzdcY1pbqQpmNW6d-Fe8k_-b8KnMVc8J7Dh3k&dib_tag=se&keywords=4amp+battery+tender&qid=1732463640&sprefix=4amp+%2Caps%2C328&sr=8-5

I will say yes. And I will say so because this charger does not merely provide one state of charge, but advertises having different states of charge (e.g. full and float) that we can fairly presume get entered into depending upon the device polling your battery for its state of charge to determine not only what state of voltage it is in, but using different algorithms for making that determination based upon the type of battery (i.e. the battery's chemistry, e.g. AGM (absorbent glass mat, as in your JL: a lead acid variant that can charge and discharge quickly, flooded (also a lead acid variant) or Lithium Iron Phosphate (LiFePO4) you set it for.

Do note that aside from the word "Lithium," Lithium Iron Phosphate and Lithium Ion batteries are worlds apart.

Lithium Iron Phosphate (LiFePO4) is considered a very stable chemistry, safe enough from off gassing to even place in a vehicle cabin--not, mind you because LiFePO4 batteries are so safe in and of themselves, but because invariably such batteries are equipped with Battery Monitoring Systems (BMS) that make them so.

LiFePO4 batteries pack more juice per pound that the various Lead Acid batteries but, barring those with heating elements or user setups, experience issues below freezing, particularly with anything but the slowest of chargings.

Charging batteries is not unlike the consumption of food on our soon to be Thanksgiving: as we get fuller, it's best to slow down.

 

[Nokones]

Oh, I forgot to mention in my recent post that my batteries have outlived most of my battery chargers. Who would think.

I just ordered a 25-Amp Odyssey Battery Charger for my soon to be installed Odyssey Dual Battery System in my 23 Wrangler Rubi. We'll see how this charger will work on the dual batteries.

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