Plug in to Maintain 12V Battery

[Frebster]

It’s part of battery management.

I’m certain it means exactly what it says, system off to save battery.

Doesn’t mean [12V] battery’s discharged or anything untoward.

HV battery will charge LV battery when it requires through the DC/DC charger whether the car is on & READY or off and parked up.

Only exception as far as I am aware is if HV battery’s very low but that’s within our control.

Avoid overthinking these things is my advice.

That's exactly my understanding.

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[MachEMaster]

I follow this formula, ABPI=Always Be Plugged In.

 

[Secret Sauce]

You shouldn’t, your car is saying your LVB is low. You should charge it.

No, that isn't what this message says at all. Look, we know Ford's convoluted messaging system seems like it was designed by someone at Microsoft, but this message is still technically accurate. It's saying that some 12v systems were turned off to protect the battery and will be restored when you start the car. Which is exactly what happens. Interpreting this as a warning message is alarmist, because, well, it isn't a warning message. In fact at least one member of this forum checked that theory with a voltmeter and found his 12v wasn't low after seeing it.

Seems those of us who drive our cars less often see this message more often. Which if you don't treat it like a warning, makes perfect sense.

(Sorry just noticed others responded to this in a similar way. Sorry for the repetition.)

 

[WJD]

I have a '22 MME AWD ER since April ’22.

I often get a message on FordPass “Plug in to Maintain 12V Battery.”

I usually drive less than 100 miles a week, often a mile a day.

How can I keep the 12V Charged so as not to receive this message and keep my batteries healthy.

I have an Emporia home charger running at 40 AMPs.

 

[SFT-NY]

This is very helpful thread. I have had 12V warnings in the past and the warning last week. My car is typically used for very short trips so sounds like the 12V charging issue could be the result

 

[WJD]

I have a '22 MME AWD ER since April ’22.

I often get a message on FordPass “Plug in to Maintain 12V Battery.”

I usually drive less than 100 miles a week, often a mile a day.

How can I keep the 12V Charged so as not to receive this message and keep my batteries healthy.

I have an Emporia home charger running at 40 AMPs.

I have a 2021 which I have twice left in the garage, not plugged in, for 5 months and have never gotten this alert.

 

[Ned]

How does one go about checking the voltage on the 12 battery? How can it be charged with a home charger if it dies?

 

[Mach1E]

No, that isn't what this message says at all. Look, we know Ford's convoluted messaging system seems like it was designed by someone at Microsoft, but this message is still technically accurate. It's saying that some 12v systems were turned off to protect the battery and will be restored when you start the car. Which is exactly what happens. Interpreting this as a warning message is alarmist, because, well, it isn't a warning message. In fact at least one member of this forum checked that theory with a voltmeter and found his 12v wasn't low after seeing it.

Seems those of us who drive our cars less often see this message more often. Which if you don't treat it like a warning, makes perfect sense.

(Sorry just noticed others responded to this in a similar way. Sorry for the repetition.)

Except that the message never shows up when your LVB is fully charged.

I had never seen that message until last week, and sure enough my LVB was low. Charged It and it went away.

If someone tested with a volt ohm meter and saw it wasn’t low, it may be they didn’t wait until the car went to sleep to test it.

 

[Teslaeata]

I have a 2021 which I have twice left in the garage, not plugged in, for 5 months and have never gotten this alert.

The only time we should see the attached message is if we allow our HV battery to get too low on charge:

 

[Teslaeata]

Otherwise the following applies…..

 

[Secret Sauce]

Except that the message never shows up when your LVB is fully charged.

I had never seen that message until last week, and sure enough my LVB was low. Charged It and it went away.

If someone tested with a volt ohm meter and saw it wasn’t low, it may be they didn’t wait until the car went to sleep to test it.

Nobody outside of Ford engineering knows what thresholds they use to kick in this power saving mode, but we should know what the message literally says. We can also know that many of us see the battery saving message quite often and have never, ever had a low 12v battery warning. In my case, in nearly a year and a half of ownership. The low battery warning is a separate alert that you will receive if a low battery condition actually occurs.

 

[valeriol]

Dunno. This car seems weird when it comes to the 12v.

I got this message twice today for the first time ever (took delivery Oct 2021). My LVB was at 12.3v so I charged it to 13.

My HVB was around 90%.

I had this once in the past and then twice yesterday. We don't drive ours much, typically 10-20 miles/week. I checked the 12V battery reading in Car Scanner and it said 12.2V, so I left the car on 30 minutes. The car is stored in a parking garage and later I'll stop by to see what it reads now.

Addendum: I just read the post on reconditioning the 12v battery and noticed the paragraph on OBDII adapters. I just got one recently (that's what Car Scanner uses) and didn't realize that it's best practice to unplug it while the car is parked. I will do that later today when I check on the car.

 

[Mach1E]

Nobody outside of Ford engineering knows what thresholds they use to kick in this power saving mode, but we should know what the message literally says. We can also know that many of us see the battery saving message quite often and have never, ever had a low 12v battery warning. In my case, in nearly a year and a half of ownership. The low battery warning is a separate alert that you will receive if a low battery condition actually occurs.

It is a low 12v battery warning. But not the “super low” warning. As you stated it’s a separate alert.

Another way to read it? If you get that warning, your 12v is a little low. Just like it was for the post just prior to this one.

You can test it yourself next time you get the alert. My guess is you’ll be between 12.2 and 12.4 like others have posted here including myself.

 

[TheSteelRider]

Nobody outside of Ford engineering knows what thresholds they use to kick in this power saving mode, but we should know what the message literally says. We can also know that many of us see the battery saving message quite often and have never, ever had a low 12v battery warning. In my case, in nearly a year and a half of ownership. The low battery warning is a separate alert that you will receive if a low battery condition actually occurs.

It displays if there is not enough energy left in the Flux Capacitor to make it back home.

 

[Mrs Chivus]

These “Plug in to maintain the 12v” messages had essentially stopped a while ago after software updates and a visit to the dealer. Ever since the 6.1 software update they are back with a vengeance. Anyone else seeing this correlation?

Yes. Same thing with me. I was getting them and reported it to Ford. They said to ignore them, that they didn't mean anything. Then they were fixed with one of the updates. I got FPU6.1 on 10/12 and got the "Plug in...." message later the same day.

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