Raymondjram

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Amazing.
The batteries on my Super Duty Power Stroke Diesel trucks die every 22-24 months. Both of them. On both of my personal trucks AND all 18 that we have in our fleet at work. Truck runs fine one day, next day they are dead. No warning lights....dead enough for the truck not to start. 10 volts required to activate the IDM or the injectors wont work.

My wife's C-Max Energi 12v battery died a couple weeks ago. Had to use the physical key to unlock the door, pop the hood, connect jumper cables to the terminals under the hood to provide power to pop the lift gate and access the 12v battery which is right next to the HVB. So close in fact that Ford doesnt even publish instructions or tell the owner where the battery is located. The owners manual just says "see your dealer for service".

Luckily I have the service manuals and am EV trained so I feel comfortable working near the HVB to access the 12v battery. Finding a replacement when the dealership was closed was fun....but we have everything here in Phoenix so I was able to locate a new one and get her car working again.

I dont remember ever owning a vehicle where the 12v battery did NOT wear out eventually.
My 2014 Fusion Hybrid also has both batteries in the trunk, but the 12V unit is accessed by a removable cover on the left side, which is very visible. It was replaced by the dealer at no cost under warranty after one year. The second one is still working today.

This is why I mentioned about a lithium-ion version for the Mach-E, which may cost more but last longer. I am planning to get four lithium-ion cells and build my own replacement for my Fusion.

I recommend Ford to add a standard battery connector used in some UPS installations instead of two loose wires in the Mach-E for the emergency access when the 12 V battery fails. Then just sell a cable set with the same connector on one end and jumper clamps on the other end.
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Raymondjram

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@ARK, you may have a phantom current leak. Power down everything in your Mustang, get a ammeter to measure DC current, disconnect the 12V positive, then connect the ammeter between the positive cable and the battery post (meter positive to post and meter negative to cable). If you measure some active current, it should be some device (maybe a clock or alarm system), so try removing the fuses for such devices, one by one. When the current reading drops, you found it.
 
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JamieGeek

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Seems like in the MME, there is no reason to start it or set a preconditioning schedule (for that purpose anyway). It takes care of itself.
Sure; that is how its supposed to work as per this thread.

Sometimes things don't go always as planned either and its helpful to have a backup strategy.
 

Blanked

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Living in an area where some residents live long term on Islands that have no road access, they choose to park their vehicles at the Embarkation Points. I've seen some parked and covered for more than 12 months.

This leads me to the question:
Is it OK to utilize a Solar Panel situated in the MME Panoramic Roof with a Trickle Charger to the 12v Battery? Should not be any different than our ICE or our RV and House Batteries... or am I wrong?

Ford Mustang Mach-E Darren Palmer talks Mach-E 12V battery and first OTA software update 1612183241036

Ford Mustang Mach-E Darren Palmer talks Mach-E 12V battery and first OTA software update 1612183173955
 

Blinkin

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I don't mind Ford giving every one a second key fob. However, I think you should know that you can use PIN code open the door AND drive the car.
I was also skeptical of the 1 key fob decision until I understood that 2 PINs can get you in and driving without a fob or working PAAK. I'm fine with it - most people would just throw their 2nd fob into a drawer and forget about it.
 


GoGoGadgetMachE

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You probably won’t believe this but in 33 years of driving I’ve never had a dead battery.

I'm not planning on starting now.
On a related note, "not starting now" is typically the problem with a dead 12V battery.

?
 

226ra

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I believe my i3 only maintains the 12V battery charge while the car is on and maybe while it's charging. If you let the car sit for an extended period, the 12V can definitely die.
Same with my Honda Clarity, which I always found strange given the huge drive battery is right there. Great to hear that this may not be the case with Mach-E.
 

sockmeister

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Mine is almost completely stock in this . There is an aftermarket anti-theft system, but the mechanic I took it to tested that by unplugging the system. It stayed with him for five weeks last year as he tried to see what was drawing on the battery.

He didn’t find anything, thought the battery’s connectors to the car were really dirty with build up of something (don’t remember exactly what he said) and he cleaned it real good. So basically he thought it was a charging issue, where these blocked connectors weren’t letting the car charge right. The car started doing much better after he did this. Before, if I didn’t drive it for four days the battery could be dead, so dead that I wouldn’t even be able to get the locks to work. After this, I went for several months without a dead battery until recently.

Now I think because my six CD changer is busted, the Shaker 500 sometimes gets stuck trying to shuffle between non-existent CDs. This might be a new cause for battery drain... The joys of 15 year old cars.
It shouldn't be that bad though. It could be something like resistance between the alternator and battery. Your mechanic should check with an ammeter for parasitic draw on the battery when off.
But, let's not hijack this thread haha. I'm sorry you're having that problem. Even 20 year old cars shouldn't do that. Hope you get it fixed.
 

sockmeister

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Living in an area where some residents live long term on Islands that have no road access, they choose to park their vehicles at the Embarkation Points. I've seen some parked and covered for more than 12 months.

This leads me to the question:
Is it OK to utilize a Solar Panel situated in the MME Panoramic Roof with a Trickle Charger to the 12v Battery? Should not be any different than our ICE or our RV and House Batteries... or am I wrong?

Ford Mustang Mach-E Darren Palmer talks Mach-E 12V battery and first OTA software update 1612183173955
You could, but there'd be no point. The high voltage battery will maintain your 12v, as mentioned in this thread and the manual.
You'd be better off somehow trying to keep the HVB charged above 50%.
 

available_username2

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Sure; that is how its supposed to work as per this thread.

Sometimes things don't go always as planned either and its helpful to have a backup strategy.
but because it has to connect the hv battery to charge it, it has a monitoring system. So if something goes wrong your car is going to send you a message that your 12v isn't being charged
 

JamieGeek

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but because it has to connect the hv battery to charge it, it has a monitoring system. So if something goes wrong your car is going to send you a message that your 12v isn't being charged
Is it? I didn't see that in the owner's manual. That is a pretty big assumption.

Granted we used to occasionally get fault notifications like this with the Focus Electric but they weren't that reliable. Hopefully the Mach-E improves on that.
 

Florida7382

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Id3 owners in Europe are reporting problems with the 12V battery dying, and WV is trying to fix that with software update (which will have to be performed at the shop, car left overnight). e-tron forums are speculating if the HV battery charges the 12V as in some literature it says it does, but people still are reporting problems of the 12V dying. Also, in the e-tron at least, you’re not supposed to jump/replace the battery yourself but it’ll be a tow trip to the dealer...
 

Daraiders76

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My 2006 Mustang has been jump started a few dozen times, unfortunately. It has some sort of fault within it. Changed the battery multiple times over the years, taken it to a few different mechanics to see where the drain is coming from or what the issue is, no one can isolate it or figure out what the source is. Last mechanic did something that improved the issue but didn’t fully resolve it.

Anyway, as hopeful as we are that our Mach Es will turn out perfect, it’s likely that some of us will have a gremlin or two to deal with, like with any make/model. Hopefully not with the 12v as it seems like much more of a PITA to deal with than on an ICE.
I have a 2008 Acura MDX- great car but the battery always died. I was frustrated beyond belief. Did a bit of research and found out it was a faulty Blue Tooth module. Opened up the center console, took that BT unit out and battery hasn't died since! I never replaced it just because I never got around to it.
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