Main battery replacement

[bobbylinn]

2023 Sport-S

My main battery has failed, so I replaced it today. While doing this replacement I pulled the F42 fuse and removed the smaller of the two ground cable from the main battery. I expected the auto stop start to then be inoperable. On my test drive the auto stop start engaged. What do I need to do now?

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[ChrisNLA]

2023 Sport-S

My main battery has failed, so I replaced it today. While doing this replacement I pulled the F42 fuse and removed the smaller of the two ground cable from the main battery. I expected the auto stop start to then be inoperable. On my test drive the auto stop start engaged. What do I need to do now?

Auto stop-start still works, like this - you just don't get an error light is my understanding.

You still have to press the button on the dash or buy the thing that remembers the last button setting or use a Tazer or other device to disable auto stop-start.

 

[Mr._Bill]

2023 Sport-S

My main battery has failed, so I replaced it today. While doing this replacement I pulled the F42 fuse and removed the smaller of the two ground cable from the main battery. I expected the auto stop start to then be inoperable. On my test drive the auto stop start engaged. What do I need to do now?

ESS cannot be disabled. There are multiple methods to prevent it from turning off the engine when it calls for it, but that's it. ESS is an integral part of the system. Removing the F42 fuse just disables the relay so the startup test is done on the Main Battery instead of the Aux Battery. You still have to hit the button on the dash every startup.

 

[bobbylinn]

Thanks for the clarity. I have hooked up the aux. battery again since I feel like it is still functioning properly,.

 

[OCJosh]

You may want to rethink that. It's my understanding that if you don't replace the aux battery at the same time, that the aux battery may drain the main battery to charge back to up to it's "optimal" level thereby really defeating the purpose of changing the main battery to begin with.

 

[Mr._Bill]

The Aux battery can last much longer than the Main, and sometimes it fails before. What matters is the state the Aux Battery fails in. When mine failed, it was just dead and had no effect on the system. It took me six months to get around to replacing it.

 

[Lost1wing]

Thanks for the clarity. I have hooked up the aux. battery again since I feel like it is still functioning properly,.

Do yourself a favor and charge both of your batteries. Do not rely on driving the Jeep to charge them.

 

[bobbylinn]

I charged both batteries (old main battery) for 6 hours and 2 hours later the old main battery, when tested at OReilly, was at 11.6V. Thats why I replaced it. I did not test the aux but it started the vehicle with bad battery so I assumed it was OK.

 

[BourbonRunner]

In order to properly bypass the auxiliary battery: Remove it, then take the positive from it, fish it back up to the main and drop it on the positive terminal of the main. It's easier to do this removing the fuse block instead of going at it through the fender. Be sure to tape off the negative cable and zip tie it away safely.

Then, pull fuse 42 so the computer does its startup ESS system check on the main battery instead of the missing auxiliary. ESS will still work but will use the main to do its thing.

To "disable" ESS , it requires either an auto-start eliminator harness or a Tazer. Technically those don't really disable it either, they just "remember" the last setting on ESS, you turn it off and the device will recall that next time you start it up.

Since you're replacing your main, now is a good time to upgrade to a larger, stronger starter/main battery. An H7 drops in the factory location with zero modifications. I have the Odyssey, many have Optimas and a handful of folks have gotten the Antigravity lithium batteries with the jump start feature.

 

[AOGAudiman]

Thanks for the clarity. I have hooked up the aux. battery again since I feel like it is still functioning properly,.

What are you trying to achieve? Disable the Auto Start/Stop? Prevent the batteries from draining? I am using Tazer to disable the Auto Start/Stop and I have disabled the Aux battery, as you have to save my main battery.

 

[Mr Miami]

Not to pee on a parade that seems to go on forever, but what is the big deal with the stop/start thing? You get in the vehicle, you turn it off. My wife gets into her BMW, she presses the switch and it turns off (or when it "happens" later on the drive).

We turn on or off the radio, we change the station, we adjust the volume, we adjust the climate control or turn the air or heat on or off.

Is pressing the button to turn off the on/off thing such a big deal? Sometimes I forget to do it and never notice it. Other times, if I am at a red light and it shuts off, as soon as I start I press the button and it goes away.

What is the issue that is so frustrating to so many with this?

 

[BourbonRunner]

@Mr Miami its an annoyance. No more, no less.

But in the case of these trucks the aux battery it relies on can be problematic and potentially leave you stranded.

 

[Mr Miami]

@Mr Miami its an annoyance. No more, no less.

But in the case of these trucks the aux battery it relies on can be problematic and potentially leave you stranded.

Why do you find the facts annoying. I guess clicking the seat belt is annoying to some. It's the way it is.

But yes, that auxiliary battery thing is a real PITA.

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