Dead MME !

[Don_23805]

Did you by chance test the voltage from cig lighter for pwr on and pwr off. That will be the first thing I do if I get the warning... from any place about charge issue. 900 miles seems crazy. Almost like an overhead light was left on...

Didn't check the 12V level. FP message seemed to indicate hat "headlights left on" would affect range, a function of the HVB. Think the problem was leaving the MME plugged in, even though it had fully charged overnight and the 12V charging bug had not been fixed. Never seen the 12V battery, but without needing hundreds of Cranking Amps like ICE, it's probably no bigger than on my lawn mower battery.

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[Don_23805]

Unfortunately you are probably correct, especially in cold locations and if the car isn't driven more than a couple of times a week most of the time.

I would expect that with 90 kwh in the HVB as a charging reserve for the 12V that it would stay charged for a long time.

 

[Don_23805]

Maybe both have an issue and so the HVB is dragging the 12v down. I do hope you get resolve. I have 190 miles (since 12/8)...

The dragging down should be the 12V (slowly) dragging down the HVB since that is its charging source. Still suspect that the "12V not charging when charging cable is plugged in" bug didn't get fixed.

 

[Don_23805]

I would be afraid of putting this car on a transport to Florida from NY for example and it might not start when they try to deliver it.

My MME arrived at dealer day before Xgiving. They said it was only half charged and they would top it off (which would have delayed delivery a day). I said I'd take it at current charge level since I'm only 25 miles away, and have had charger ready to go since April ;=)
I think if you put it on the Amtrak Autotrain, fully charged, there would be plenty of juice to keep the 12V charged for that trip

 

[dixiekidd88]

Still waiting for a diagnosis from the dealership ours was towed to after shutting down on the interstate with no restart and dead 12v. The tech that looked at it and started on it 'called out sick' yesterday and no update today.... This was the codes shown right before it shut down, just at a loss of words now

 

[kennethjk]

Still waiting for a diagnosis from the dealership ours was towed to after shutting down on the interstate with no restart and dead 12v. The tech that looked at it and started on it 'called out sick' yesterday and no update today.... This was the codes shown right before it shut down, just at a loss of words now

Maybe the car has Covid

 

[dixiekidd88]

Maybe the car has Covid

?‍

 

[Crilly]

A deep cycle battery is less likely to short out when draining and recharging. I know sealed batteries can short out. (Not hold a charge)

 

[Mawby]

The dragging down should be the 12V (slowly) dragging down the HVB since that is its charging source. Still suspect that the "12V not charging when charging cable is plugged in" bug didn't get fixed.

True. Could also just be a bad 12v battery period. They fail too. Why 900 miles to kill it. Laptops sometimes are troubled for 30 days but if you use it 1x month. You just went past the 1 year warranty.

 

[Don_23805]

My dealer seemed to have gotten over their lack of personnel (perhaps with some out of department pressure) and emailed that it was fixed and they would deliver it shortly. They said the problem was a bad cell in the 12V battery. Sounds too familiar.

 

[Mach1E]

My dealer seemed to have gotten over their lack of personnel (perhaps with some out of department pressure) and emailed that it was fixed and they would deliver it shortly. They said the problem was a bad cell in the 12V battery. Sounds too familiar.

All that speculation and it was just a bad battery?

Oh well, at least it’s a super easy fix.

 

[Don_23805]

Not sure that's all of it. Going to install my BT OBD reader today and also check out the recovery connectors.

 

[Shayne]

A deep cycle battery is less likely to short out when draining and recharging. I know sealed batteries can short out. (Not hold a charge)

A fob in your pocket and a huge deep cycle RV battery with jumpers in the frunk. Don't leave home without them . Maybe I do need to take out my dividers from the frunk after all; just to get my spare battery in there ?. Should not laugh too loud as a spare 12V and jumpers on a trip has now crossed my mind. Maybe the ACDelco and keep it on a maintainer.

It appears to me to resemble the motherboards cmos battery but unlike the MB it is rechargeable and if it is charged and maintain then it should last a long time. The MB silver dollar cmos batteries last years and you can't charge those. They die quicker if the machine is not ran much but as noted you can not charge them.

My guess not the battery size or type and possibly defective 12V's (or a component) or a logic problem as all the hardware and power it needs to maintain the 12V is sitting right there. If I can do it with a charger plugged into 120V when an ICE is not running I should be able to when plugged into in an EV charging port. Got to be a trickle charger logic in there somewhere? Don't think the size of the cmos battery would be a big deal if healthy and maintained.

My dealer seemed to have gotten over their lack of personnel (perhaps with some out of department pressure) and emailed that it was fixed and they would deliver it shortly. They said the problem was a bad cell in the 12V battery. Sounds too familiar.

I am sitting in that position too. Try it and hope it does not die for the 3rd time. A least so far I have dodged the bullet that @dixiekidd88 caught. Didn't like hearing that story.

Not sure that's all of it. Going to install my BT OBD reader today and also check out the recovery connectors.

The more info the better. ?

 

[Ford Motor Company]

Still waiting for a diagnosis from the dealership ours was towed to after shutting down on the interstate with no restart and dead 12v. The tech that looked at it and started on it 'called out sick' yesterday and no update today.... This was the codes shown right before it shut down, just at a loss of words now

Hi there. Can you send us a DM with your VIN and dealership info? I can look into this on my end.

 

[Rjm]

Lately I have been getting this screen when I start my Mach E. 3 out of the last 4 starts. Has anyone else seen this or can you offer any insight. Could the 12 volt battery be having problems

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