Battery discharge at rest

[Cartman]

I replaced both the main and auxiliary batteries. I put dynamic AGM 70Ah and 12Ah. I drove and charged them to 100%. After about 4 hours with the car parked and locked, both batteries dropped to 88%.
That means about 9Ah in 4 hours. That's about 2.2A per hour. And the car would be completely discharged after less than two days.
What is your idle consumption?

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[Reinen]

Nowhere near that much. I haven't specifically measured it but that's what I'd expect after a week, not 4 hours. Looks like you have something siphoning off power or preventing the JL from going into true sleep mode.

 

[Mark75H]

I had to think about it for a minute. I would be concerned if the voltage continued to drop at that indicated rate, but if it stopped there, I wouldn't worry that much

 

[Heimkehr]

I replaced both the main and auxiliary batteries. I put dynamic AGM 70Ah and 12Ah. I drove and charged them to 100%. After about 4 hours with the car parked and locked, both batteries dropped to 88%.

That means about 9Ah in 4 hours. That's about 2.2A per hour. And the car would be completely discharged after less than two days.

As you're no doubt aware, there's a not-insignificant parasitic draw that needs to be identified and reconciled, not least because of the recent expense of two new batteries. You might consider checking for secure ground (earth) connections first, starting with the batteries themselves.

What is your idle consumption?

Unknown. To determine that value, I'd have to connect a volt meter that is energized while the ignition is off. That means it'd be measuring its own parasitic draw, if nothing else. I'll defer doing so until I perceive an issue that needs to be attended to.

 

[THAW]

Are you sure your battery meter/app is accurate? It's just a voltmeter right? If so, I'd be skeptical of both (100%, 88%) readings. And, the margin of error in your Ah calculation is likely too large to definitively determine you have abnormal idle consumption.

In any case, two or 3 Amps draining from the battery/batteries during the initial ~12 hour period after shut down is normal.

 

[Ratbert]

In any case, two or 3 Amps draining from the battery/batteries during the initial ~12 hour period after shut down is normal.

Shouldn't normal parasitic draw be in the 20 to 50 milliamp range? 3 amps over 12 hours would be in the 250 milliamp range.

 

[THAW]

Shouldn't normal parasitic draw be in the 20 to 50 milliamp range? 3 amps over 12 hours would be in the 250 milliamp range.

The initial idle phase consumes more power until modules enter sleep mode and various processes complete. I typically see an IBS Quiescent Current of 1000-2000 mAh (it's presented as a range) after my vehicle sits overnight, and 2000-3000 mAh over a couple days.

OP observed the first 4 hours, which is likely to have a higher consumption rate than a longer period. Then again, maybe his wireless battery meter consumes a lot of power.

 

[Ratbert]

The initial idle phase consumes more power until modules enter sleep mode and various processes complete. I typically see an IBS Quiescent Current of 1000-2000 mA (it's presented as a range) after my vehicle sits overnight, and 2000-3000 mA over a couple days.

OP observed the first 4 hours, which is likely to have a higher consumption rate than a longer period. Then again, maybe his wireless battery meter consumes a lot of power.

Those numbers seem incredibly high to me. More like what you'd expect during the first 15-ish minutes after shutdown. I'm no expert though.

 

[Pape]

ya this is really high IMO.
Back in the JK it was around 80 MA after 1 minutes, when tested I got 55 MA.
Recommended to pull the fuse out and see what is consuming, also get the normal value for sleep mode and when is sleep mode happening so you know what the time line and value should be.
Also did you validate the app number with actual voltage ?

 

[mister flanders]

Typical draw is less than 20mA once all modules are in sleep mode. The service manual gives a nominal base vehicle Ignition-OFF Draw (IOD) of 25mA and states:

If the IOD is over 50 milliamperes, the problem must be found and corrected before replacing the battery.

My guess is that the app is wrong and the battery is fine. I would put a charger on it and monitor charging current. Current will fall below 200mA pretty quickly if it's near a full charge, and below 100mA within an hour or two. If it stays above 500mA for more than a few minutes it's not fully charged or the vehicle has excessive IOD.

 

[hamiamham69]

I seem to remember seeing a video on the ‘tube walking you thru how to track down parasitic draw on Wranglers. Even if not specific to Wranglers the method is still the same and only requires a multi-meter which can be had for $20.

That being said the oftentimes battery was percentages are often so wildly inaccurate as to be almost useless

 

[AndySpill]

I replaced both the main and auxiliary batteries. I put dynamic AGM 70Ah and 12Ah. I drove and charged them to 100%. After about 4 hours with the car parked and locked, both batteries dropped to 88%.
That means about 9Ah in 4 hours. That's about 2.2A per hour. And the car would be completely discharged after less than two days.
What is your idle consumption?

I'm sorry I'm not answering your idle consumption question Andrew beyond the generalities of that which you report being way to high.

That said, as I know you are familiar with, and in the interest of trouble shooting, can I get you to temporarily yank the Aux battery cable and wrap its end in electric tape and also effect the Fuse 42 pull?

I asked this because if your consumption significantly changes for the better as a result of this temporary change, you may be looking at a bad, even though new, Aux battery.

 

[THAW]

@Cartman , I believe you've indicated in previous posts you have JScan. You can use it to check the SOC of your main battery as assessed by the IBS to compare to that provided by your accessory meter/app. And, as alluded to in my above posts, you can check the IBS assessment of your idle consumption (main battery only) by viewing Quiescent Current. Both IBS metrics are found in the Live Data of the Body Controller Module.

 

[Mguy]

I replaced both the main and auxiliary batteries. I put dynamic AGM 70Ah and 12Ah. I drove and charged them to 100%. After about 4 hours with the car parked and locked, both batteries dropped to 88%.
That means about 9Ah in 4 hours. That's about 2.2A per hour. And the car would be completely discharged after less than two days.
What is your idle consumption?

Your photo shows voltages and percentages (apparently SOCs) during charging, both irrelevant for determining inherent and parasitic loads after shut down. So I don't think it useful to decipher and consider your reported data for diagnostic purposes.

 

[mister flanders]

Those numbers seem incredibly high to me. More like what you'd expect during the first 15-ish minutes after shutdown. I'm no expert though.

Indeed, those numbers are absurd. The service manual says all modules should be in sleep mode after one hour. Mine actually takes one minute longer.

The current falls rapidly. The entire discharge from the moment you stop molesting it to full sleep mode 61 minutes later is around 200mAh.

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