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Will the battery protect itself from drainage?

mgroeger

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Heading out camping this weekend and will be sleeping in the Jeep. I plan on running a little 8", 120v fan from the power outlet on the backside of the center console. I suspect that running that will drain the battery so was wondering if at some point the battery kills power to the outlet if it gets low. Anyone have real life experience or info on this?
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Let me start off by saying im no expert and im struggling to understand the dual battery setup but I dont believe it has any drain protection from what ive been reading. Youll just drain the battery to the point there isnt enough voltage to start the Jeep and if it does drain, you'll need another vehicle to jump it as a battery jumper isnt sufficient due to the 24v ESS battery. If you're going alone i wouldn't risk it imo. Im in the same boat, im going for a 4 day solo camping trip in Utah and would like to run a little fan but im worried ill be stranded alone in the Valley of the Gods. I dont have the funds to install a dual battery or deep cycle battery just yet either
 

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Heading out camping this weekend and will be sleeping in the Jeep. I plan on running a little 8", 120v fan from the power outlet on the backside of the center console. I suspect that running that will drain the battery so was wondering if at some point the battery kills power to the outlet if it gets low. Anyone have real life experience or info on this?
Using the inverter outlet is not as power efficient as using a 12 volt fan. You can find them at an RV store and some don’t have large amp draws. I like the Caframo compact fans as they are quiet and only draw .55 amps
 

Ma$$iveDebtAche

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Let me start off by saying im no expert and im struggling to understand the dual battery setup but I dont believe it has any drain protection from what ive been reading. Youll just drain the battery to the point there isnt enough voltage to start the Jeep and if it does drain, you'll need another vehicle to jump it as a battery jumper isnt sufficient due to the 24v ESS battery. If you're going alone i wouldn't risk it imo. Im in the same boat, im going for a 4 day solo camping trip in Utah and would like to run a little fan but im worried ill be stranded alone in the Valley of the Gods. I dont have the funds to install a dual battery or deep cycle battery just yet either
Nope, 12V and many on here have reported success using a jump starter.
 

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Tumbleweed

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Nope, 12V and many on here have reported success using a jump starter.
I couldn't find anything (or maybe didnt understand) as i searched through quite a few threads. do you know if you just attach the jumper to main battery terminals like normal or do you have to disconnect one of the batteries first? Any links would be greatly appreciated! Thanks
 

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Woa, everyone let's take a step back here.

@Tumbleweed : 24 V? Do you know something I don't about the OPs @mgroeger that wasn't listed in the post (i.e. that it's a 2.0L JL as opposed to a 3.6L)? In fact his footnote says he's got a 3.6L. That's !2V.

Most people have the 3.6L. If you do OP then know that 99.9% of the time your main and ESS/Aux battery sit in parallel with one another, including when the rig is off and parked, and as a result, any drain on either battery effects both. Such a parallel connection (plus to plus, neg. to neg.) ups amperage while keeping voltage roughly unchanged (12v).

OK Mike, lets intersect your questions with known attributes of the rig. :)

The 120V outlet you speak of behind the console remains energized only while the rig is cranked. I should be more specific. If the rig is in an ESS event, and technically not cranked, the ESS/Aux battery will energize it until the sooner of you taking your foot off the brake and the engine re-cranks, or the appliance drains the ESS/Aux battery enough that the JL decides to crank the rig for you, before taking your foot off the brake, while it still has enough battery power (both batteries) to crank the engine, and have the alternator then supply power off the running engine.

The USB ports, according to the manually, only remain on for a while after the rig is shut down.

The 12V cigarette port in the front is also an accessory outlet: energized only when the rig is on. I should be more specific. One button push of the starter may be enough to turn it on without cranking the engine--I haven't tried.

If you have the 12V cigarette port in the cargo area, that outlet by default from the factory is energized all the time. You can move a fuse under the hood, as per the manual, to change it to work as an accessory outlet.

Now...power draw. Many things have been written on the board about this but I'll try to condense it. Testing shows that your ESS/Aux battery, all on its own, must have a basic level of power for the 3.6L JL to cold crank. If this battery is dead, or you disconnect it, your main battery could be a 12V nuclear power plant and the rig won't crank.

But once the rig has determined that this ESS/Aux battery has adequate power, BOTH batteries supply power for the crank. This is why you can crank a 3.6L with a fully energized ESS/Aux battery alone, with the main battery disconnected, but not vice versa.

I've written some long winded pieces on the hows and whys of maximizing the chance of getting a booster pack to crank your 3.6L but it has to be a relatively substantial one, and it has to be hooked up a certain way.

Let me know if you're interested and we'll climb down that "rabbit hole."

Cheers.
 

Rahneld

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OK..I can see more is needed based on the thread's direction.

Conventional jump starting of a 3.6L involves a method no different in connection than any other ICE (Internal combustion engine) vehicle. The thing that is different is there is a waiting period once the jumper cables are connected to the main battery's terminals.

This waiting period charges both batteries, most importantly the ESS/Aux--which it can because like I said, both batteries are in parallel when the rig is at rest. It's most important for the ESS/Aux battery to have this current because it's going to, as discussed above, be tested by the rig in isolation for current, that if inadequate, the JL will not let the attempt to crank the engine proceed.

A technique I wrote about on another thread seeks to connect directly to the ESS/Aux battery from a power pack, or I guess jumper cables from another vehicle. The theory here is the power pack's current isn't drained as much charging the ESS/Aux battery, preserving its power for the crank.

More for another post if interest exists.

Some people like to disconnect the two batteries while camping and drain power from the main battery. As long as your ESS/Aux battery has sufficient power you can then crank you rig off of it, and AFTER, reconnect the main battery. You don't want to reverse this order because once the batteries are connected, power will flow to the weaker battery: in this case presumably the main one, used during camping. Best to do this only after a successful crank and the alternator charges both.
 
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mgroeger

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OK..I can see more is needed based on the thread's direction.

Conventional jump starting of a 3.6L involves a method no different in connection than any other ICE (Internal combustion engine) vehicle. The thing that is different is there is a waiting period once the jumper cables are connected to the main battery's terminals.

This waiting period charges both batteries, most importantly the ESS/Aux--which it can because like I said, both batteries are in parallel when the rig is at rest. It's most important for the ESS/Aux battery to have this current because it's going to, as discussed above, be tested by the rig in isolation for current, that if inadequate, the JL will not let the attempt to crank the engine proceed.

A technique I wrote about on another thread seeks to connect directly to the ESS/Aux battery from a power pack, or I guess jumper cables from another vehicle. The theory here is the power pack's current isn't drained as much charging the ESS/Aux battery, preserving its power for the crank.

More for another post if interest exists.

Some people like to disconnect the two batteries while camping and drain power from the main battery. As long as your ESS/Aux battery has sufficient power you can then crank you rig off of it, and AFTER, reconnect the main battery. You don't want to reverse this order because once the batteries are connected, power will flow to the weaker battery: in this case presumably the main one, used during camping. Best to do this only after a successful crank and the alternator charges both.
OK, thanks for the info!

In terms of my scenario I can some up all of your dissertation with this one quote from you, "The 120V outlet you speak of behind the console remains energized only while the rig is cranked."
The Jeep won't be running while I sleep so it's back to the old AAA battery operated camping fan for this trip.
Thanks for the education though, I only fell asleep once while reading it ;)
 

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OK, thanks for the info!

In terms of my scenario I can some up all of your dissertation with this one quote from you, "The 120V outlet you speak of behind the console remains energized only while the rig is cranked."
The Jeep won't be running while I sleep so it's back to the old AAA battery operated camping fan for this trip.
Thanks for the education though, I only fell asleep once while reading it ;)
Didn't know what you're willing to do before answering. Cargo area outlet is an option too if you have one.
 
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mgroeger

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Didn't know what you're willing to do before answering. Cargo area outlet is an option too if you have one.
Yeah I have one, but on such short notice we will go with battery operated for this trip.
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