Vehicle Power Down Timer

[JJR]

Would work better if you used a L1 charger because it’ll take longer letting the 12v charge more.

You could also get it down to say 10% and just let it slow charge for the 3-4 days and that will charge the 12v nicely. But you’ll need to do it again in a couple weeks.

Granted even if you don’t want to go the battery tender route. I don’t think you need to run it 12 hours to get it back up to a decent charge anyway. Pretty sure 30min-1hr is sufficient.

When all this LVB baloney started I installed a battery monitor that is connected to the LVB and displays the battery health on my phone.
I believe my LVB drops about .06v in 24 hours.

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[RickMachE]

When all this LVB baloney started I installed a battery monitor that is connected to the LVB and displays the battery health on my phone.
I believe my LVB drops about .06v in 24 hours.

I believe that is understated.

 

[Rj786]

I keep it plugged to an L1 charger when I am away. Had done this in winter for three weeks in a row when the temps are -10c at night and found no issues on my return. Car is parked inside in a non heated Garage.

 

[dbsb3233]

Don't know if this really works, but leaving it on the L2 charger and setting a daily departure time might wake it up and drain enough juice to force it to HVB charge a little each day, even if only for 30 minutes or something. Might help.

 

[JJR]

I believe that is understated.

Did you see the graph on my phone?

 

[JJR]

The whole purpose of my post was to point out that if you turn off the timer double check that it stays off.

 

[ARK]

OP, what does not driving much mean?

I bought my MME in February 2021 and was fully remote with work for more than a year after that.

For the past two years, I'd only go into work on average twice a week.

I also have another car that I sometimes drive, and my work is only a few miles away from me.

As a result, I'd regularly go a few days without driving my Mach-E at all, and even then, would only be driving for like 30 minutes total for the day, before the same thing would happen again.

During many work weeks in 2021, I felt I had bought a really expensive front-yard ornament because as much of a looker as the car was, I was driving it so infrequently.

I never took any steps to try and maintain the low voltage battery and mine still seems to be running fine. I don't know when the low voltage battery gets installed by Ford, but my particular Mach-E was manufactured in November 2020 - no one was driving it all for 2.5 months from manufacture to delivery.

Anyway, my low voltage battery still seems to be fine, I have not had issues with it. Unless your driving is truly extraordinarily infrequent, I think you may not need to bother to try and manually keep the LVB charged.

 

[Mach-Lee]

If it "wakes up" to charge battery. Couldn't it wake up charge 12v and then go back to sleep? Wether plugged in or not?

That's exactly what it does when the 12V battery gets low.

300W is the idle draw of the car's modules (about 50 of them). Can't reduce that without a hardware redesign.

 

[milepost1]

That's exactly what it does when the 12V battery gets low.

300W is the idle draw of the car's modules (about 50 of them). Can't reduce that without a hardware redesign.

I did not know that. I really mean that. Question then at what point does car stop charging 12v and allow it to go dead? Or are 12v batteries just reaching end of life?

 

[Maquis]

I’ve owned my Mach-E for almost 3-1/2 years. Sometimes it’s driven every day. Sometimes it sits a couple of weeks. I’ve never even thought about the 12V battery. I can’t imagine all of the angst implied by this thread. I just drive my car when I want to, and park it when I don’t.

 

[Sikkun]

I’ve owned my Mach-E for almost 3-1/2 years. Sometimes it’s driven every day. Sometimes it sits a couple of weeks. I’ve never even thought about the 12V battery. I can’t imagine all of the angst implied by this thread. I just drive my car when I want to, and park it when I don’t.

Ford agrees you should start thinking about it after 30 days.

 

[Mach-Lee]

I did not know that. I really mean that. Question then at what point does car stop charging 12v and allow it to go dead? Or are 12v batteries just reaching end of life?

The recharge threshold depends on the software level and how long the battery has been low. With the latest software I believe it will recharge at around 45%.

The people that run into 12V failures are usually because:

• They have outdated software with bugs
• They have an unresolved 12V drain such as a dashcam
• They park the car with less than 15% HVB - "Plug in to maintain 12V battery"
• The 12V battery has reached end of life and suddenly dies

Not much you can do about the last one other than proactively replace the 12V battery every 3-5 years (do what's typical in your climate).

 

[milepost1]

The recharge threshold depends on the software level and how long the battery has been low. With the latest software I believe it will recharge at around 45%.

The people that run into 12V failures are usually because:

• They have outdated software
• They have an unresolved 12V drain such as a dashcam
• They park the car with less than 15% HVB - "Plug in to maintain 12V battery"
• The 12V battery has reached end of life and suddenly dies

Not much you can do about the last one other than proactively replace the 12V battery every 3-5 years (do what's typical in your climate).

Thank you

 

[Maquis]

Ford agrees you should start thinking about it after 30 days.

I’m aware of that. But it seems that a lot of people are expending a bunch of unnecessary effort to keep the 12V battery charged. The OP never did answer the question “What does ‘not driving much’ mean?”

 

[JJR]

OP, what does not driving much mean?

I bought my MME in February 2021 and was fully remote with work for more than a year after that.

For the past two years, I'd only go into work on average twice a week.

I also have another car that I sometimes drive, and my work is only a few miles away from me.

As a result, I'd regularly go a few days without driving my Mach-E at all, and even then, would only be driving for like 30 minutes total for the day, before the same thing would happen again.

During many work weeks in 2021, I felt I had bought a really expensive front-yard ornament because as much of a looker as the car was, I was driving it so infrequently.

I never took any steps to try and maintain the low voltage battery and mine still seems to be running fine. I don't know when the low voltage battery gets installed by Ford, but my particular Mach-E was manufactured in November 2020 - no one was driving it all for 2.5 months from manufacture to delivery.

Anyway, my low voltage battery still seems to be fine, I have not had issues with it. Unless your driving is truly extraordinarily infrequent, I think you may not need to bother to try and manually keep the LVB charged.

I did the math and I average 2.1 miles per day.
I took delivery April 2022 and the mileage is less than 1700.
Before I began the regimen of turning the car on, I would receive warning messages saying that the 12v battery needed service. Also, because of the low voltage, OTAs would not install. Those problems have disappeared.

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