12v battery problem can have serious consequences

[louibluey]

Unfortunately this isn't just an MME issue. Almost all modern cars have no key hole anymore to manually open a door and obviously you can't open the hood if your 12v dies on any other vehicle either without being able to access the cabin and hood release.

IF there's an immediate need to get someone out when it's -30 then that's why God invented big rocks!

Otherwise you just wait for a tow to air-wedge the door open or if the 12v is dead use the hood release in the front bumper.

It has been warmer in recent years, but odd as sounds, for a lot of us -25F to -30F is just winter (fortunately only a few days in December/January for most of us). We go about life as usual, maybe dressing a little warmer

I lived in the foothills just east, elev. 1,000 ft, when I first moved here from the NJ/NYC metro area. My first morning out on the thruway (-27F), I spritzed the windshield only to have it ice over opaque! We even have to use special windshield fluid, either that peach color rainX, or Prestone used to have a yellow -30F fluid too.

Sponsored

 

[RickMachE]

The Lightning has a key.

The only reason for this is that the Lightning is an F-150, with EV added. They're not going to remove keys on door handles just because it's an EV, nor add fancy buttons to open doors.

Or maybe because the average F-150 owner wouldn't be able to figure out how to push the button?

#IOwnAnF-150

 

[Wildthing]

No mather the draining and the outside temp, there is no reason that the battery doesn't keep is charge. It should be automatically be charged by the HVB. My Hyundai Kona had a LED in the fron bumber that lit when the 12V battery was charging. And it happened even while not plugged to a charger.

Is Ford US is aware of the situation? I spoke with Ford Canada service manager this week and he was not aware of the situation. It seems that dealers make the the repair on a case by case basis, mostly by replacing the batteries. Some had the problem more than once. I don't think that the battery is the problem. I tought the the March 2021 TSB solved that issue.

Do we know if it can happens to any car, whatever the build date or the software version?

 

[TheQ42]

The earlier production Mach-E's have sensors, hardware, and software in place with the goal of maintaining the 12V battery. I'm not sure what sort of rumor you're hearing (or spreading?) but I'm going to assume later production models are still produced with the intent of maintaining the batteries.

Wasn't attempting to spread anything, just trying to learn if they changed anything. I honestly do not know, and it seems like we've got a lot of knowledgeable people here. I'm assuming the same hardware is in place, but it is reasonable to assume software updates could improve the situation since the hardware is there. Just dunno if any software updates have been aimed at the problem.

 

[macchiaz-o]

Wasn't attempting to spread anything, just trying to learn if they changed anything. I honestly do not know, and it seems like we've got a lot of knowledgeable people here. I'm assuming the same hardware is in place, but it is reasonable to assume software updates could improve the situation since the hardware is there. Just dunno if any software updates have been aimed at the problem.

We don't know a lot of details on most updates ("some bugs were squashed"). But one of the very first updates, from March 2021, addresses an issue where the LVB might not be charged while the HVB charger is connected.

My car was built a few months prior and doesn't yet have that fix (it hasn't been back to a dealer), but it also hasn't stranded me or anything like that. Unfortunately this is an example of a fix that service technicians can load but Ford hasn't pushed it OTA yet.

 

[RMoore]

Incorrect, they read Kelvin natively.

Actually I think neither of you is correct. Most would typically read a voltage drop that has some relationship to the temperature, depending on the device. This is then converted to a temperature, with the units depending on which scale is chosen. I don't think any temperature scale is really "native" here, the way Kelvin is from a thermodynamics or statistical mechanics perspective, but we might now be getting more into semantics (then again this whole argument is I suppose ?).

 

[dtbaker61]

here in Quebec we have been experiencing a wave of polar cold for a few days. We reached temperatures of less than 30 Celsius. Several Mustang Mach-E owners have had issues with the 12v battery. One of the people who had this problem was put in a situation that would have serious consequences as she described in her post on the FB site « propriétaires Mustang Mach-E Quebec ».
''A really worrying situation happened to me with my MME premium AWD this morning: I had 115km of autonomy and after a few stops during my shopping my car did not start and I heard a noise in the speakers . I called roadside assistance and there was a 1:30-2:30 wait so someone came to pick me up because I was with my 10 month old baby in the car. After 20 minutes when I got out of the car the door closed behind me and the doors wouldn't open anymore and my baby was stuck in the car for another 30 minutes while the police and the the tug arrives. The tug wasn't able to open the door as it's all electric and there is no emergency way to open the doors if the battery is dead...had to have my dealer move on place and he opens the hood with an intrumejt and dismantles plastic parts to access the battery so that the doors open and I can get my baby out. Words fail me to tell you how my mom's heart suffered during this episode and that I really don't want it to happen again…. After reflection I want to know if this happened to another of you? And here are my solutions and I especially want to hear yours. My car is at the dealership for diagnostics. I would like to be able to have confidence in my vehicle and I will need them to be very convincing for me to agree to take it back…
- change of battery for a more powerful one?
- added smart charger?
- display the level of the 12 volt battery and an alert if it drops below a critical threshold
- Make a reminder for doors that do not have an emergency opening system

Thanks for helping me think through all this….’’
I hope Ford will fix this problem once and for all….
Ps Sorry for m’y english

a very unfortunate and I am sure scary set of circumstances. A lot of the stress could have been avoided if the OP knew there was the emergency charge port on the front bumper, which would have powered up the car enough to use the door pillar unlock code.

The baby-in-the car stress could have been avoided by disabling the 'lock on walk away' setting. I would suggest that its a big mistake to ever lock a baby in a car... whether its hot or cold, or just for a minute.

....and for all those living in frigid places, I would highly recommend buying a 12v electric blanket, pull the Frunk panels and stuff the blanket around the 12v battery, connect it to the 12v connection points next to the battery with some D-rings that won't shake loose, and leave that sucker on all winter. It will pull energy from the HV battery, but avoid all the temperature related problems.

 

[chrisGT]

Cold makes the problem worse but I don't think it is the root cause.
At temperature 45-50f (8-10 Celsius) my GT's 12v Soc can drop 10-20% overnight. I have seen (with Car Scanner) the 12v SoC dropping from 90% to 60% in less than two days with the car parked, Paak disabled, both keys far away and not using Fordpass. It is not that cold here.
I believe something is draining the 12v battery too fast and Ford has to fix it.
That also explains why some owners have experienced the issue even after their 12v batteries were replaced. Something is draining them.

 

[HuntingPudel]

a very unfortunate and I am sure scary set of circumstances. A lot of the stress could have been avoided if the OP knew there was the emergency charge port on the front bumper, which would have powered up the car enough to use the door pillar unlock code.
<SNIP>

The two leads in the front bumper are not charge leads. They are leads that activate the electric frunk release and only work if the 12V battery is dead. Once the frunk is open, the tow truck driver would need to remove two beauty panels, then apply jumper cables to the battery jump points in order to get the car to a point where the doors could be opened. ?‍?

The MME has no emergency charge port. Some people have drilled holes into their beauty panels and capped them off in order to access the jump points more easily. I added this:

 

[Fordmaybe]

The two leads in the front bumper are not charge leads. They are leads that activate the electric frunk release and only work if the 12V battery is dead. Once the frunk is open, the tow truck driver would need to remove two beauty panels, then apply jumper cables to the battery jump points in order to get the car to a point where the doors could be opened. ?‍?

The MME has no emergency charge port. Some people have drilled holes into their beauty panels and capped them off in order to access the jump points more easily. I added this:

Do you have a write up on this install. Looks like a great idea

 

[dtbaker61]

The two leads in the front bumper are not charge leads. They are leads that activate the electric frunk release and only work if the 12V battery is dead. Once the frunk is open, the tow truck driver would need to remove two beauty panels, then apply jumper cables to the battery jump points in order to get the car to a point where the doors could be opened. ?‍?

The MME has no emergency charge port. Some people have drilled holes into their beauty panels and capped them off in order to access the jump points more easily. I added this:

oh yeah, I almost forgot the holes I cut in my 'beauty panels' were partly for emergency charging in addition to Energy Export.... It really only takes 5 minutes if you have a 2" hole saw. Caps cost about a dollar each at a hardware store.

This was the first mod I did after I took delivery of me MME.
https://www.macheforum.com/site/threads/how-to-add-access-ports-for-lvb-connection-points.4107/

 

[dtbaker61]

Cold makes the problem worse but I don't think it is the root cause.
At temperature 45-50f (8-10 Celsius) my GT's 12v Soc can drop 10-20% overnight. I have seen (with Car Scanner) the 12v SoC dropping from 90% to 60% in less than two days with the car parked, Paak disabled, both keys far away and not using Fordpass. It is not that cold here.
I believe something is draining the 12v battery too fast and Ford has to fix it.
That also explains why some owners have experienced the issue even after their 12v batteries were replaced. Something is draining them.

my guess is that the root cause is not that something is mysteriously draining the 12v.... Its a mysterious combination of temperature, HV state of charge, and bad software parameters that are not 'waking up' the HV dc-dc converter to maintain the LVB voltage.

but yes, Ford should address it of course.

If you live in a really cold place, and have to park the MME outside for any length of time, I'd suggest:
- wrapping a 12v electric blanket around the LVB and leaving it on 24x7
- or, leaving the MME 'on' and turning the 'auto-off' setting off, and manually locking doors.

even with cabin heat off, this would maintain HV battery temp, and maintain the LVB at 14.4v rather than let the MME go to sleep.

 

[bruceski88]

my guess is that the root cause is not that something is mysteriously draining the 12v.... Its a mysterious combination of temperature, HV state of charge, and bad software parameters that are not 'waking up' the HV dc-dc converter to maintain the LVB voltage.

but yes, Ford should address it of course.

If you live in a really cold place, and have to park the MME outside for any length of time, I'd suggest:
- wrapping a 12v electric blanket around the LVB and leaving it on 24x7
- or, leaving the MME 'on' and turning the 'auto-off' setting off, and manually locking doors.

even with cabin heat off, this would maintain HV battery temp, and maintain the LVB at 14.4v rather than let the MME go to sleep.

I lost 1% of HVB charge in 3 weeks of sitting in a 40-50F garage. went into deep sleep and woke up no problem

 

[JeffGo]

One day last week, I could not get the doors unlocked, and bluetooth from the phone was not active. The car had been sitting in my driveway for about 65 hours, temps in the 40s the whole time, 55% HVB, no indication of a 12V battery problem but it sure seemed that way. Absurdly, FordPass was able to remotely "start" the car, consoles and parking lights on but still no door unlocking (or bluetooth connected). I had to run off to an appointment and took my wife's car. When I came home, I plugged in my charger. In less than 5 minutes, everything was working again. An OBD scanner showed my 12V battery well above 70% SOC minutes later.

I know Ford has made changes to when the DC/DC converter kicks in if the car is on the charger and I thought off as well. My car is reasonably up-to-date with dealer updates about 2 months ago. Looks like they need to keep working on it.

And yeah, this whole crazy pop the frunk, remove panels, etc. I don't care how they implement it, keyhole or not, but they have to do something.

 

[HuntingPudel]

Do you have a write up on this install. Looks like a great idea

There are pix of the install at page 3 of https://www.macheforum.com/site/threads/frunk-tub-removed-pics.12094/

I never fully wrote it up. The more popular method is to cut two 2” holes in the beauty panel and place furniture caps on the holes. There are several write-ups on that. ??

Sponsored