Monitor your 12Volt battery

kennethjk

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@kennethjk what's the procedure for checking this? are you just turning off the car and getting out while running car scanner and checking right then? at some point the OBD2 power goes away, right?
I turn on the car, plug in the obd2 and then check the battery section right then. I drove around this morning for 15 minutes or so to get 12V battery SOC us to 88%
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@kennethjk what's the procedure for checking this? are you just turning off the car and getting out while running car scanner and checking right then? at some point the OBD2 power goes away, right?
The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off. It won't change or update while the car is on. You don't have to get out or do anything special, just use the Car Scanner app with an OBD reader.

I don’t t have any 3rd party apps that I am aware of. No utility company integration. The welcome lighting goes off after 5 seconds, or thereabouts, so not sure how that will make a difference but I will try.

the codes the dealer sent me was but not sure they are relevant to this issue.

thanks
6837F2AE-10B0-4342-BF91-A1B7B258861C.jpeg
See my note about having them fix the grille shutters.

The welcome lighting likes to keep going off when you store your keys within 40' of the car at home. You aren't going to be in the garage when it keeps turning on, so you probably have no idea unless you have video surveillance on the parked car.
 

kennethjk

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The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off. It won't change or update while the car is on. You don't have to get out or do anything special, just use the Car Scanner app with an OBD reader.



See my note about having them fix the grille shutters.

The welcome lighting likes to keep going off when you store your keys within 40' of the car at home. You aren't going to be in the garage when it keeps turning on, so you probably have no idea unless you have video surveillance on the parked car.
Thanks , I missed your last sentence about grille.

the key is in a faraday bag and I on,y use PAAk and phone at night is around 50 ft.

my wife’s FOB is a bit closer but will take your advice
 

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The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off. It won't change or update while the car is on. You don't have to get out or do anything special, just use the Car Scanner app with an OBD reader.
ah, interesting, ok.

how about the 12V SOC? i assume that's a moving target since the HV battery starts to charge the 12V battery as soon as the car is fully powered up, right?
 

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If you have welcome lighting and walk away locks disabled, does having the fob or PAAK still do anything to wake up the car when in proximity? I was assuming if it was already left unlocked, the keys should have no effect when nearby anymore, but hard to tell if it could still be waking the computer without any indication like lights anymore.
 


kennethjk

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If you have welcome lighting and walk away locks disabled, does having the fob or PAAK still do anything to wake up the car when in proximity? I was assuming if it was already left unlocked, the keys should have no effect when nearby anymore, but hard to tell if it could still be waking the computer without any indication like lights anymore.
Every time I walk the car by with my phone in my pocket all kind of things start to happen in the car, clicks, lights whirling sounds etc
 

Mach-Lee

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how about the 12V SOC? i assume that's a moving target since the HV battery starts to charge the 12V battery as soon as the car is fully powered up, right?
Yes, it will slowly charge while the car is on all the way to 100%. It just takes a long time.

If you have welcome lighting and walk away locks disabled, does having the fob or PAAK still do anything to wake up the car when in proximity? I was assuming if it was already left unlocked, the keys should have no effect when nearby anymore, but hard to tell if it could still be waking the computer without any indication like lights anymore.
No, it shouldn't. My fob is fairly close by and you can see my drain number is low because I have welcome lighting off.

Every time I walk the car by with my phone in my pocket all kind of things start to happen in the car, clicks, lights whirling sounds etc
Turning off welcome lighting should help with that. Otherwise you need to get the BCM and RFA modules updated to fix the "waking up" issues. I see you have a few updates:

Ford Mustang Mach-E Monitor your 12Volt battery 1678330389692


Note: The GFM update should be done at the same time as the BCM update. Afterwards they can enable the frunk release button on the screen:

Ford Mustang Mach-E Monitor your 12Volt battery 1678330577005
 

kennethjk

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Yes, it will slowly charge while the car is on all the way to 100%. It just takes a long time.



No, it shouldn't. My fob is fairly close by and you can see my drain number is low because I have welcome lighting off.



Turning off welcome lighting should help with that. Otherwise you need to get the BCM and RFA modules updated to fix the "waking up" issues. I see you have a few updates:

1678330389692.png


Note: The GFM update should be done at the same time as the BCM update. Afterwards they can enable the frunk release button on the screen:

1678330577005.png
Don’t know what the GFM update will do , thanks for the tips.

the frunk and trunk buttons already show up as I have updates thru 4.1.3
 

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Don’t know what the GFM update will do , thanks for the tips.

the frunk and trunk buttons already show up as I have updates thru 4.1.3
GFM is the frunk module. That and the BCM need to be updated together otherwise you'll get a warning message every time you start the car.
 

kennethjk

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GFM is the frunk module. That and the BCM need to be updated together otherwise you'll get a warning message every time you start the car.
Interesting that I have the button and I just checked that it works. Not on the main screen but 1 level in , on the mode page

thanks again
 

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Looks like OBD2 dongle left in diagnostic port overnight, remember to unplug the OBD2 adapter after use.

Some ELM327 dongles have auto power-off mode, but all others might keep the electronics awake for very long time and quickly drain the 12v battery.
 
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Shayne

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The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off. It won't change or update while the car is on. You don't have to get out or do anything special, just use the Car Scanner app with an OBD reader.
Thanks for the definition.

Mine I have seen in the 50's so I would say OPer is not alone. I have seen it at 80 mA and 17 mA looking back at OBD so it does vary. Maybe how many times it got woke or other factors contribute to the variation? Mine varies and not sure what the difference between 0.020 to 0.050 Amp would make? The 12V battery says 35 Ah on its sticker so 50% drain would be 36 days and 15 days respectfully. You would think it should not have much of an impact if the car maintains the 12V with the big one. Few more cycles on the 12V. Not sure exactly why mine bounces around guess not too worried as long as the car boots.
 

JimmyMachE

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"The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off."

The last part of the sentence is important. The quiescent current probably does NOT measure power draw in active state whenever electronics is woken up by some internal logic or external polling (Fordpass, 3rd party apps) in a locked vehicle.

Total energy draw overnight should probably be assessed by the drop in the %SOC of the 12V battery from evening to next morning. Of course, one should account for normal (or abnormal if degraded) battery self-discharge rate, and slight SOC fluctuations due to temperature change in a lead-acid battery.

High quiescent current (50+ mA) is probably a circumstantial evidence of such frequent wake-ups in a locked car, especially if paired with a significant drop in the 12V % SOC overnight.
 

kennethjk

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"The quiescent current (parasitic draw) is an average over the past 24 hours, it's measured by the BMS system when the car is off."

The last part of the sentence is important. The quiescent current probably does NOT measure power draw in active state whenever electronics is woken up by some internal logic or external polling (Fordpass, 3rd party apps) in a locked vehicle.

Total energy draw overnight should probably be assessed by the drop in the %SOC of the 12V battery from evening to next morning. Of course, one should account for normal (or abnormal if degraded) battery self-discharge rate, and slight SOC fluctuations due to temperature change in a lead-acid battery.

High quiescent current (50+ mA) is probably a circumstantial evidence of such frequent wake-ups in a locked car, especially if paired with a significant drop in the 12V % SOC overnight.
Thanks

I turned off wake up lights last night and my car 12V SOC went front 76% at 10 pm to 66% at 6 am this morning.

is that normal.

the QA went from 43 last night to 34 this morning
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