Draining the battery vs draining ESS battery - 2024 V6

[acheron800]

Lithium (LiFePO4) and AGM batteries have identical discharge temperature ranges. With LiFePO4, however, you don't want to charge them below freezing. That can be mitigated with a heater, of course. You also don't want to charge AGMs by more than .3C when it's below freezing.

While LiFePO4 batteries are initially more expensive they're also significantly lighter with nearly double the usable amperage for a given stated capacity (again: don't drain an AGM battery below 50%...~11.95v).

LiFePO4 batteries have 3k to 5k+ charge cycles while AGMs are in the ~500 range.

So yes, you'll anecdotally "have good luck" with AGMs if you don't care about weight, capacity, lifespan, or spending more long-term for multiple AGMs.

The only real disadvantage of LiFePO4 in this application is that you'll need a DC-to-DC converter.

I'll stand by my statement. Lithiums don't work in cold weather.

For my application with a pushrod V8 in my moho and the cost difference. I'll take the AGM all day, everyday. I have 3 of the fuckers and we hardly put a dent in them.

That's neither here nor there. Talking about using or isolating batteries in the wrangler for limited camping usage.

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[acheron800]

When I first installed my Tazer apparently I failed at the 2 sleep cycle step and it drained my battery down to 4 volts. I couldn’t even unlock the doors with the key fob and the eTorque battery was no help trying to start the Jeep.

Good info! Thanks.

 

[Ratbert]

I'll stand by my statement. Lithiums don't work in cold weather.

Which is obviously incorrect. Like I said, lithium (LiFePO4) and AGM batteries have identical discharge temperature ranges. Identical. You simply can't charge LiFePO4 when it's below freezing. If that's your use case then you buy one with a built-in temp controlled heater.

 

[acheron800]

Which is obviously incorrect. Like I said, lithium (LiFePO4) and AGM batteries have identical discharge temperature ranges. Identical. You simply can't charge LiFePO4 when it's below freezing. If that's your use case then you buy one with a built-in temp controlled heater.

Hence, it doesn't work (as a battery should).

In a battery I look for both characteristics, charging and discharging.

Compromising to rely on a computer chip or a "built in heater" is unacceptable and simply unsafe when reliability is king.

I will opt for the tried and true AGM battery at a fraction of the price and guaranteed reliability. Worst case, wet cell deep cycle at an even cheaper cost before going lithium.

I had this same thought struggle in the past. Almost went lithium for the moho when the wets shit the bed for the 90-99% discharge usage. Decided it wasn't worth it.

Agree to disagree.

 

[Ratbert]

Hence, it doesn't work (as a battery should).

In a battery I look for both characteristics, charging and discharging.

Compromising to rely on a computer chip or a "built in heater" is unacceptable and simply unsafe when reliability is king.

I will opt for the tried and true AGM battery at a fraction of the price and guaranteed reliability. Worst case, wet cell deep cycle at an even cheaper cost before going lithium.

I had this same thought struggle in the past. Almost went lithium for the moho when the wets shit the bed for the 90-99% discharge usage. Decided it wasn't worth it.

Agree to disagree.

If you're that serious about using AGMs in extreme cold then make sure you don't run them low in those temperatures. Their freezing point drops as they drain. At a SG of 1.15 they have a freezing point of 5F. At that point it's toast.

 

[Red Willy]

I may be a little confused here, but if you have a 24' class C and are using the Jeep for a toad, why run lights and such off the Jeep battery?

 

[Whaler27]

I understand there are products such as the jackery, however, I like simplicity….

Then you bought the wrong vehicle…

New wranglers are hopelessly complicated, and the list of dysfunctions that flow from a drained battery is long and befuddling. When the battery condition is low/poor on a JL the jeep can lose its mind with all error lights lit up like a Christmas tree, or select error lights lit up indicating problems you don’t have. It can be like the jeep is possessed, with the wipers turning on inexplicably and every dash light lit up brightly, or it can go black and completely dead. I’ve been buying and running jeeps since 1977, and I’ve never experienced anything like it. Protect your jeep’s batteries as though your life depended on it — and get a jackery for running camp stuff. You won’t regret it.

Also, you mention buying a 4xe “for obvious reasons”. For most of us the reasoning isn’t obvious at all. I agonized about buying a 4xe for the better part of a year. I finally pulled the trigger on a 4xe Grand Cherokee a couple months ago. It’s got great power and the battery-driving is fun — like driving a 6,000 pound golf cart. If we stay in the same house, and my wife’s driving habits don’t change, and we don’t take it on long trips, and the cost of electricity doesn’t increase much, and the times when “electric not available” are short and infrequent, and the complex systems are reliable and durable, and we don’t sweat the substantial adverse net impact on the environment (from mining, powering, and battery disposal), the purchase may pencil out. We should revisit this in five or six years.

 

[acheron800]

I may be a little confused here, but if you have a 24' class C and are using the Jeep for a toad, why run lights and such off the Jeep battery?

I will be camping in the jeep, separately from the moho on trips where it is just my boy(s) and I.

Motorhorme stays home.

Then you bought the wrong vehicle…

New wranglers are hopelessly complicated, and the list of dysfunctions that flow from a drained battery is long and befuddling. When the battery condition is low/poor on a JL the jeep can lose its mind with all error lights lit up like a Christmas tree, or select error lights lit up indicating problems you don’t have. It can be like the jeep is possessed, with the wipers turning on inexplicably and every dash light lit up brightly, or it can go black and completely dead. I’ve been buying and running jeeps since 1977, and I’ve never experienced anything like it. Protect your jeep’s batteries as though your life depended on it — and get a jackery for running camp stuff. You won’t regret it.

Also, you mention buying a 4xe “for obvious reasons”. For most of us the reasoning isn’t obvious at all. I agonized about buying a 4xe for the better part of a year. I finally pulled the trigger on a 4xe Grand Cherokee a couple months ago. It’s got great power and the battery-driving is fun — like driving a 6,000 pound golf cart. If we stay in the same house, and my wife’s driving habits don’t change, and we don’t take it on long trips, and the cost of electricity doesn’t increase much, and the times when “electric not available” are short and infrequent, and the complex systems are reliable and durable, and we don’t sweat the substantial adverse net impact on the environment (from mining, powering, and battery disposal), the purchase may pencil out. We should revisit this in five or six years.

Understood, unfortunately a giant battery and a turbo make the system ever much more complicated and with more parts to fail comes less reliability.

This Christmas light feature you speak of when the battery is low, does this only apply to limited engine options? 3.6, ecodiesel, 4xe, 392? Or is this across the board?

Also the battery doesn't allow the seats to fold flat. We are planning on sleeping in the jeep.

Sleeping inside being not being an option was the dealbreaker.

 

[andy29847]

What you describe is exactly what the genesis dual battery system was meant for.

https://www.genesisoffroad.com/gen3-jl-dual-battery-kit

^^^^ THIS!!! ^^^

If you are going to be camping and powering stuff off the vehicle batteries, You need to have your accessory battery isolated. Other methods work but they require attention and management.

JL and JT Jeeps with a main and auxiliary battery can be hard to jump start. The problem is that both batteries go dead at the same time. If the 2 batteries go too far dead, they can take an extended time to recover enough to start the engine.

I have deleted the auxiliary battery for my Jeeps (JL and JT). You can replace the main battery with a an Everstart (Walmart) group 94/H7 battery that has 850 CCA. The 850 number is nearly equal to the 2 Jeep stock batteries.

What would be interesting would be a way to isolate the auxiliary and use it alone to power you toys. The 2 complications are wiring you accessories to the aux battery and charging the aux battery. A mini fuse box would be how I would hadle power distribution. A DC-to-DC charger wired to a circuit that is active only when the engine is running might work for charging.

Regardless of how you do this, it is expensive and/or complicated. If I was considering this kind of activity, I would buy a small suitcase generator and figure out a way to carry it.

Best Suitcase Generators For Charging Your Gadgets Off The Grid (vanclan.co)

 

[STW]

^^^^ THIS!!! ^^^

If you are going to be camping and powering stuff off the vehicle batteries, You need to have your accessory battery isolated. Other methods work but they require attention and management.

JL and JT Jeeps with a main and auxiliary battery can be hard to jump start. The problem is that both batteries go dead at the same time. If the 2 batteries go too far dead, they can take an extended time to recover enough to start the engine.

I have deleted the auxiliary battery for my Jeeps (JL and JT). You can replace the main battery with a an Everstart (Walmart) group 94/H7 battery that has 850 CCA. The 850 number is nearly equal to the 2 Jeep stock batteries.

What would be interesting would be a way to isolate the auxiliary and use it alone to power you toys. The 2 complications are wiring you accessories to the aux battery and charging the aux battery. A mini fuse box would be how I would handle power distribution. A DC-to-DC charger wired to a circuit that is active only when the engine is running might work for charging...

+1
I have wondered if Genesis (or another vendor) could make a cable-set with switch-set that would use the Main and Aux up to function like their dual battery system. So first you will do the jumperless disconnect, pull fuse 42, etc., so the Aux is no longer operating in parallel (that's how I run with Aux on board but neutered and out of the system), and then install this aftermarket Genesis-style harness with switching that would allow the Main and Aux to operate like their double battery system.

Problems with this idea would include that the Genesis system is designed for two identical size batteries so adjustments would need to be make for a big/little battery setup. And might provide fewer advantages because of that.
Also a problem for Genesis since they'd rather sell their dual battery box setup.

For me there is no question that I do not want to run the ESS system the way Jeep has implemented it with two batteries wired in parallel the way they did it. I don't mind ESS in general, but to have it set up so your batteries kill each other steadily unless charging conditions are perfect--that's crazy. And then, worse as you say, our OEM parallel dual battery system prevents a jump after causing the need for it.

From my point of view the necessary steps are:
1) jumperless disconnect.
2) then decide how to manage what's left. If you did this on day one, then just run the OEM AGM Main battery happily for the years it lasts. If your Main/Aux system has already damaged itself like mine did, then replace your Main with something good and high capacity. Turn off ESS. Either leave your Aux in place, disconnected, so you can reconnect for a dealer repair visit without getting hassled and blamed for diverging from stock. Or remove that Aux and save 15 lbs of weight. Or replace both Main and Aux with the Genesis system or similar.

 

[andy29847]

+1
I have wondered if Genesis (or another vendor) could make a cable-set with switch-set that would use the Main and Aux up to function like their dual battery system. So first you will do the jumperless disconnect, pull fuse 42, etc., so the Aux is no longer operating in parallel (that's how I run with Aux on board but neutered and out of the system), and then install this aftermarket Genesis-style harness with switching that would allow the Main and Aux to operate like their double battery system.

Problems with this idea would include that the Genesis system is designed for two identical size batteries so adjustments would need to be make for a big/little battery setup. And might provide fewer advantages because of that.
Also a problem for Genesis since they'd rather sell their dual battery box setup.

For me there is no question that I do not want to run the ESS system the way Jeep has implemented it with two batteries wired in parallel the way they did it. I don't mind ESS in general, but to have it set up so your batteries kill each other steadily unless charging conditions are perfect--that's crazy. And then, worse as you say, our OEM parallel dual battery system prevents a jump after causing the need for it.

From my point of view the necessary steps are:
1) jumperless disconnect.
2) then decide how to manage what's left. If you did this on day one, then just run the OEM AGM Main battery happily for the years it lasts. If your Main/Aux system has already damaged itself like mine did, then replace your Main with something good and high capacity. Turn off ESS. Either leave your Aux in place, disconnected, so you can reconnect for a dealer repair visit without getting hassled and blamed for diverging from stock. Or remove that Aux and save 15 lbs of weight. Or replace both Main and Aux with the Genesis system or similar.

Removing the negative and pulling F42 isn't enough. The aux needs to be fully separated from truck systems. I believe you would need a jumper between N! and N3. The only advantage to using the aux battery is that Jeep has a place designed to carry it.

 

[Whaler27]

I have the Genesis system. I think it's great, but it's expensive, it's not fool proof, and it's not the solution for everybody. If you have significant parasitic draw, it will drain down quickly and leave you just as stranded.

On of the advantages of the Genesis system is having readily accessible batteries that can be swapped or jumped easily in the Walmart parking lot, or wherever. It doesn't require contortion, removal of a tire and wheel, or disassembly of the power center. That's a big plus, for me.

We had LiPHo4 batteries in our motorhome. They were MUCH lighter, had MUCH more available power than the OEM AGM batteries, they held power better in storage, and they charged MUCH faster, regardless of the charging source.

For a camping solution, I'd want something small and light that charges easily and quickly and delivers great power. I went with Jackery and a couple solar panels, but there are lots of options -- and all provide some redundancy and peace of mind if something gets left on and your jeep's electrical system shits itself.

 

[Ratbert]

This Christmas light feature you speak of when the battery is low, does this only apply to limited engine options? 3.6, ecodiesel, 4xe, 392? Or is this across the board?

Across the board.

 

[Vanburi]

Remember with the genesis system to wire all accessories to the aux and not the main. The system has a feature that isolates the main starter battery if the voltage drops to a certain point. Also, you have the button you can push to force the 2 batteries to connect together for self jump starting.

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