12V Battery Suddenly Draining Quickly With "Electrical System Drain Service Required" Message

[SalsabyJake]

I'm having this issue on a 2023 Premium Extended Range. I've had the car about 4 weeks and have had no problems. Took the car out for a drive today, left at about 85% and came back about 70% (on the HVB).

A couple of hours later, I got a notification on FordPass titled '''Electrical System Drain Service Required" and telling me it's "possibly caused by after-market device(s). If that's not the case, please schedule service soon"

I can confirm I have no after market devices installed. I plugged in my ODB monitor, and the 12V battery is draining between 10 and 15A.

I'm staying at a friends in a remote area and several 100 kms from my dealer. Is there any way to resolve this issue? And I don't want to be stranded with the car, is leaving the car on for a few days until I can drive to the dealer a reasonable solution?

What a pain... As a fallback, you can plug the car in using the mobile charger (that used to come free with a new MachE) to keep the 12V charged up until you can figure things out. Maybe it's the battery itself? Ford seems to have some supply issues with it. My '23 MME has been fine for 20 months, but I think about pre-emptively replacing the 12V battery soon. Although if they have a batch of crappy ones, that might not be wise!

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[garyd9]

What a pain... As a fallback, you can plug the car in using the mobile charger (that used to come free with a new MachE) to keep the 12V charged up until you can figure things out. Maybe it's the battery itself? Ford seems to have some supply issues with it. My '23 MME has been fine for 20 months, but I think about pre-emptively replacing the 12V battery soon. Although if they have a batch of crappy ones, that might not be wise!

The "mobile charger" (L2 EVSE) doesn't charge the 12v battery directly. It will charge the HVB, and while the HVB is charging, the HVB will charge the 12v battery. However, once the HVB stops charging (either because it's full or because of a charge stop point), the 12v won't be charged anymore.

 

[SalsabyJake]

Thanks for clarifying! I was never sure about that. Does the HVB charge the 12V whenever it needs it, even when parked?

 

[garyd9]

Thanks for clarifying! I was never sure about that. Does the HVB charge the 12V whenever it needs it, even when parked?

In theory, when the 12v battery gets below a certain threshold (45% SOC, I think), the car is supposed to use the 12v battery to wake up the inverter which will charge the 12v from the HVB. IF your 12v battery is in good shape, this should work.

 

[woody]

Yes it does, it’s just not labeled clearly.

so what does 12v charge level have to do w/ est. distance? I thought 12v health was measured (as w/ a multimeter) in volts, eg 12.2 or 12.4 as healthy. We used to do this once upon a time.....but must be wrong.

 

[Sikkun]

The "mobile charger" (L2 EVSE) doesn't charge the 12v battery directly. It will charge the HVB, and while the HVB is charging, the HVB will charge the 12v battery. However, once the HVB stops charging (either because it's full or because of a charge stop point), the 12v won't be charged anymore.

While true if your not at a higher charge using the mobile charger on a 120v outlet can keep your 12v being charged for days.

 

[Maquis]

so what does 12v charge level have to do w/ est. distance? I thought 12v health was measured (as w/ a multimeter) in volts, eg 12.2 or 12.4 as healthy. We used to do this once upon a time.....but must be wrong.

This is charge level. Not health.

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