Dead Main Battery, with Aux battery deleted

[Priherd]

I have a 2020 Jeep Wrangler Rubicon, which I bought brand new in April 2020. After owning the Jeep for a year or so and always hearing about the issues with the auxiliary battery draining the main battery I decided to disconnect my auxiliary battery by removing the negative cable and placing a jumper between the N1 and N3 high amp fuses. This has worked perfectly for two years or so. The original OEM main battery has continued to work properly and strongly until a month or so ago. ( Jeep is three years old and has 36000 miles on it) I got up one morning and went to start the jeep and nothing happened except the gauges went nuts. I put a multimeter on the battery and it showed 5.6 V. Not good, I figured since the battery was over three years old it had finally died. I purchased a Optima yellow top battery knowing that other people have had problems with them but I wanted to give it a shot. I installed the Optima and it worked fine until about three months later. Once again, I tried to start the jeep and the gauges went nuts and nothing happened with the ignition. I put the multimeter on the battery and it read 5 V. I placed a battery charger on the Optima and waited till it showed a 12 V charge and started the jeep and drove straight to AutoZone where I had purchased the optima battery. They replaced it with a new one without question. Heck they didn’t even test the battery I was returning! Now, a few weeks later on a cold morning, it was 29° out in Tucson, I went to start the jeep and the jeep would not start. The gauges just went nuts. Once again, the multimeter read 5 V. I recharged the Optima battery to full capacity and it has been working fine for a few weeks but I’m curious as to what might be the issue is causing this. Is it the battery or is there a problem with the jeep? Yes, I do have a taser installed in the jeep and yes I have preformed a full reboot and two sleep cycles with the Tazer as their instructions require. I have checked the jeep in the evening when it is dark out to see if any lights are on and there are none on. I have ensured all other electrical systems ( winch, air compressor, lights) are not drawing any power. When I first start the jeep the volt meter on the jeep reads 14.4V and after running it for a little while it drops down to 13.5V or less so the alternator is working. Any Ideas of what’s draining my battery?

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[CaboJim]

Sounds like a defective alternator. Just out of curiosity you mentioned that you have a winch installed. By chance, are you running a wireless remote for your winch? I have heard they can drain your battery.

 

[Fudster]

I have a 2020 Jeep Wrangler Rubicon, which I bought brand new in April 2020. After owning the Jeep for a year or so and always hearing about the issues with the auxiliary battery draining the main battery I decided to disconnect my auxiliary battery by removing the negative cable and placing a jumper between the N1 and N3 high amp fuses. This has worked perfectly for two years or so. The original OEM main battery has continued to work properly and strongly until a month or so ago. ( Jeep is three years old and has 36000 miles on it) I got up one morning and went to start the jeep and nothing happened except the gauges went nuts. I put a multimeter on the battery and it showed 5.6 V. Not good, I figured since the battery was over three years old it had finally died. I purchased a Optima yellow top battery knowing that other people have had problems with them but I wanted to give it a shot. I installed the Optima and it worked fine until about three months later. Once again, I tried to start the jeep and the gauges went nuts and nothing happened with the ignition. I put the multimeter on the battery and it read 5 V. I placed a battery charger on the Optima and waited till it showed a 12 V charge and started the jeep and drove straight to AutoZone where I had purchased the optima battery. They replaced it with a new one without question. Heck they didn’t even test the battery I was returning! Now, a few weeks later on a cold morning, it was 29° out in Tucson, I went to start the jeep and the jeep would not start. The gauges just went nuts. Once again, the multimeter read 5 V. I recharged the Optima battery to full capacity and it has been working fine for a few weeks but I’m curious as to what might be the issue is causing this. Is it the battery or is there a problem with the jeep? Yes, I do have a taser installed in the jeep and yes I have preformed a full reboot and two sleep cycles with the Tazer as their instructions require. I have checked the jeep in the evening when it is dark out to see if any lights are on and there are none on. I have ensured all other electrical systems ( winch, air compressor, lights) are not drawing any power. When I first start the jeep the volt meter on the jeep reads 14.4V and after running it for a little while it drops down to 13.5V or less so the alternator is working. Any Ideas of what’s draining my battery?

Hi James:

Did you jump N1 to N3, or N1 to N2?

https://www.jlwranglerforums.com/fo...ry-consolidated-information.25377/post-602294

 

[Priherd]

Yes, my Warn winch has a wireless remote but It doesn't work. The remote lost connectivity and I have to plug it into the winch to operate the winch. But how could a wireless remote discharge the battery?

 

[Priherd]

Hi James:

Did you jump N1 to N3, or N1 to N2?

I jumped from N1 to N3. I've read many forums on recommending diffrent ways and I decided on N1 to N3 with a fuse.

 

[CaboJim]

Yes, my Warn winch has a wireless remote but It doesn't work. The remote lost connectivity and I have to plug it into the winch to operate the winch. But how could a wireless remote discharge the battery?

If your wireless controller is wired up directly to the battery it can cause a draw on your battery.

 

[Priherd]

If your wireless controller is wired up directly to the battery it can cause a draw on your battery.

Only the winch is connected to the battery, the wireless part of my winch is built in the winch control head and once again it's dead. The remote will not connect to the winch unless you plug the remote into the cable on one end and plug the other end of the cable into the winch.

 

[Priherd]

Hi James:

Did you jump N1 to N3, or N1 to N2?

https://www.jlwranglerforums.com/fo...ry-consolidated-information.25377/post-602294

I followed your link, I will switch the jumper from N1 to N2 like in the example and see if that keeps the man battery from draining. But I'm not sure it will because I have ran with the jumper N1 to N3 for a long time with no issues. I also have never removed the Fuse #42 as I have recently read that people suggest after disconnecting the Aux battery negative wire. Not sure if that's nessecary.

 

[Viking Jeeper]

If your battery is being drained the jeep is producing something to show you. The amps in the battery cant just disappear, they have to be creating light, heat, or noise. Id say its possible you have had two bad yellow tops.

 

[Fudster]

I followed your link, I will switch the jumper from N1 to N2 like in the example and see if that keeps the man battery from draining. But I'm not sure it will because I have ran with the jumper N1 to N3 for a long time with no issues. I also have never removed the Fuse #42 as I have recently read that people suggest after disconnecting the Aux battery negative wire. Not sure if that's nessecary.

Hi again James:

I think we could benefit here from some understanding of how things work, and what's going on in addition to "James, connect this wire to this plug and be done with it."

You may know the below. I don't mean to insult. I just want to make it clear.

=============

I'd rather not make assumptions so lets begin with what is a relay. That's an electronic switch, not to be confused with the one on the wall, which is a manual switch.

That wall switch turns on and off by you exerting energy with your fingers. A relay uses electrical current to control whether a switch is on on off, upon which an entirely different circuit that runs an appliance could arguably controlled.

There's lots of relays in vehicles and they serve several basic purposes. One allows a circuit that may contain large amounts of current to be turned on or off by another tiny circuit which just needs the energy to flip the switch. Maybe you need to control a DC circuit with AC, or vice versa. In other situations relays allow items that use different current to be energized together, even though they may operate on different current, or maybe a relay in an other situation guarantees only one thing works at a time.

Relays are classified by the current they control, the current which flips the switch, and whether the current that is being controlled is on/energized when no current runs through the switch (called a normally closed relay), or only when current DOES run through the switch (normally open.)

"Normally" means here: when the switch circuit is de-energerized, is the controlled circuit closed/on or off/open.

If you've got the 120 AC plugs in your rear, they're controlled by a normally open DC relay tied into the ignition. Provided the ignition is on, it closes a switch that allows the vehicle's inverter to convert battery power to the 120 A/C of household appliances.

======================

In your JL is a normally closed relay that is energized by 12V DC and connects the two 12V DC batteries in parallel. When the relay is not energized those batteries are connected in parallel, such as while parked, and driving. The only time that relay is energized is for an instant at crank, and I believe during ESS events.

When you cold crank the engine, for a brief instant, provided fuse 42 is in place, that relay is energized, temporarily breaking the connection between the two batteries. This way your vehicle can do a quick test on the ESS battery in isolation.

If you happen to have a jumpered wire between N1 and N2 it permanently preserves the two batteries in parallel no matter whether that relay is energized or not. All calls by the vehicle to the ESS battery on N1 get routed to both batteries, or just the main battery if you have removed the ESS battery from the electrical schematic of the vehicle by disconnecting its negative cable's distal end from the negative terminal of the main battery.

If you pull fuse 42 that relay can't be energized and the batteries can't be isolated. Think of it as another way, like the fused jumper on N1 and N2, to prevent the batteries from ever being isolated. Having both in place (a pulled fuse 42 and the jumper) in not harmful, just redundant, overkill, superfluous.

Your JL is not aware of your jumper or pull of Fuse 42. It thinks it is testing the ESS battery, as would be the case from the factory.

If your dual battery JL's ESS battery lacks power at this test, an early model 2018 without updated flashing won't crank. Models after will, upon second crank test, attempt to crank off only the main battery. If successful, ESS is turned off and remains so until the next cold crank, if any, that the vehicle thinks its ESS battery has been replaced.

I hope this helps.

 

[Viking Jeeper]

If your dual battery JL's ESS battery lacks power at this test, an early model 2018 without updated flashing won't crank. Models after will, upon second crank test, attempt to crank off only the main battery. If successful, ESS is turned off and remains so until the next cold crank, if any, that the vehicle thinks its ESS battery has been replaced.

I hope this helps.

I have seen in another thread about a 392 (no ESS) but with a weak battery. The poster said sometimes it will start on second attempt to start. Is that related to what you said above? It just seemed random but appears to be purposeful although for a two battery system.

 

[Fudster]

I have seen in another thread about a 392 (no ESS) but with a weak battery. The poster said sometimes it will start on second attempt to start. Is that related to what you said above? It just seemed random but appears to be purposeful although for a two battery system.

I'm sorry Mike. I just don't know enough about the 392, and how much of the original dual battery JLs hardware they kept under the hood in this model, even if not being used.

 

[Fudster]

Hi again James:

I think we could benefit here from some understanding of how things work, and what's going on in addition to "James, connect this wire to this plug and be done with it."

You may know the below. I don't mean to insult. I just want to make it clear.

=============

I'd rather not make assumptions so lets begin with what is a relay. That's an electronic switch, not to be confused with the one on the wall, which is a manual switch.

That wall switch turns on and off by you exerting energy with your fingers. A relay uses electrical current to control whether a switch is on on off, upon which an entirely different circuit that runs an appliance could arguably controlled.

There's lots of relays in vehicles and they serve several basic purposes. One allows a circuit that may contain large amounts of current to be turned on or off by another tiny circuit which just needs the energy to flip the switch. Maybe you need to control a DC circuit with AC, or vice versa. In other situations relays allow items that use different current to be energized together, even though they may operate on different current, or maybe a relay in an other situation guarantees only one thing works at a time.

Relays are classified by the current they control, the current which flips the switch, and whether the current that is being controlled is on/energized when no current runs through the switch (called a normally closed relay), or only when current DOES run through the switch (normally open.)

"Normally" means here: when the switch circuit is de-energerized, is the controlled circuit closed/on or off/open.

If you've got the 120 AC plugs in your rear, they're controlled by a normally open DC relay tied into the ignition. Provided the ignition is on, it closes a switch that allows the vehicle's inverter to convert battery power to the 120 A/C of household appliances.

======================

In your JL is a normally closed relay that is energized by 12V DC and connects the two 12V DC batteries in parallel. When the relay is not energized those batteries are connected in parallel, such as while parked, and driving. The only time that relay is energized is for an instant at crank, and I believe during ESS events.

When you cold crank the engine, for a brief instant, provided fuse 42 is in place, that relay is energized, temporarily breaking the connection between the two batteries. This way your vehicle can do a quick test on the ESS battery in isolation.

If you happen to have a jumpered wire between N1 and N2 it permanently preserves the two batteries in parallel no matter whether that relay is energized or not. All calls by the vehicle to the ESS battery on N1 get routed to both batteries, or just the main battery if you have removed the ESS battery from the electrical schematic of the vehicle by disconnecting its negative cable's distal end from the negative terminal of the main battery.

If you pull fuse 42 that relay can't be energized and the batteries can't be isolated. Think of it as another way, like the fused jumper on N1 and N2, to prevent the batteries from ever being isolated. Having both in place (a pulled fuse 42 and the jumper) in not harmful, just redundant, overkill, superfluous.

Your JL is not aware of your jumper or pull of Fuse 42. It thinks it is testing the ESS battery, as would be the case from the factory.

If your dual battery JL's ESS battery lacks power at this test, an early model 2018 without updated flashing won't crank. Models after will, upon second crank test, attempt to crank off only the main battery. If successful, ESS is turned off and remains so until the next cold crank, if any, that the vehicle thinks its ESS battery has been replaced.

I hope this helps.

@Rhinebeck01 :

You found this post funny.

Ok. But most people take humor in posts that are a either written with some aspect of satire in them, which it's clear from context that this was a purely explanatory post void of comedy, or b) that are factually wrong or even off topic, or two or more of the above.

So that we may all learn, please share with us what's factual wrong or off topic here. The OP, no offense to him, was clearly following instructions rather than understanding, and I sincerely tried to convey to him both....which he seemed to appreciate. If I'm wrong, and that's where you find "humor," as I see it, you do a disservice to the OP and others following here to not correct me.

Be my guest to respond with solely further laughing icons. But in so doing you will IMHO not convey that you're privy to material fact that you don't wish to share.

 

[CaboJim]

James-did you ever find the root to the iuuse?

 

[Priherd]

James-did you ever find the root to the iuuse?

Not sure, I moved the jumper to N1 - N2. Now I just have to wait and see if the problem come up again.

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