Down for the count :(

[Astraea]

This might be it?
https://www.macheforum.com/site/threads/ac-delco-12v-mme-50-ah-chevy-spark-cadillac-battery.12747/


Another possible option to explore is to find a friendly worker at the parts counter and have them check to see if the police version of the Mach-E has a different battery size. The battery tray is physically larger than needed for the LVB we get so I have to believe that isn't by accident. Unnecessary weight is the silent enemy of EVs so it makes you wonder about the battery tray dimensions.
?

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking, thought this was some good info!

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[mikeho]

@dixiekidd88 @Astraea , did you send the photo of my dealership technician notes to your dealer? My car is also a Job1, delivered 2/17/2021. Changing the High Voltage Regulator seems to have fixed it for me. Been driving the car for almost a month now with no repeat issues. These issues happened in 50-60°F weather in NorCal.

@dixiekidd88 if you're in NorCal, consider talking to or bringing your car to Frontier Ford. Mine was the second car they did this fix for, so at this point, it seems like they know what they're doing.

https://www.macheforum.com/site/threads/our-ongoing-nightmare.12075/post-308916

 

[Astraea]

@dixiekidd88 @Astraea , did you send the photo of my dealership technician notes to your dealer? My car is also a Job1, delivered 2/17/2021. Changing the High Voltage Regulator seems to have fixed it for me. Been driving the car for almost a month now with no repeat issues. These issues happened in 50-60°F weather in NorCal.

@dixiekidd88 if you're in NorCal, consider talking to or bringing your car to Frontier Ford. Mine was the second car they did this fix for, so at this point, it seems like they know what they're doing.

https://www.macheforum.com/site/threads/our-ongoing-nightmare.12075/post-308916

Oh I didn't see this! Any chance you still have the paperwork and could take as full a complete picture of it as possible, while removing any personal information or I could for you before I send it over to my dealership in the morning somehow. I'll have to call and get a good contact email for them, as this could be a fix they could look into and see if it might solve my issue as well, along with any other solution I can send their way. The faster my problem gets solved the faster we can help everyone else!

 

[dixiekidd88]

@dixiekidd88 @Astraea , did you send the photo of my dealership technician notes to your dealer? My car is also a Job1, delivered 2/17/2021. Changing the High Voltage Regulator seems to have fixed it for me. Been driving the car for almost a month now with no repeat issues. These issues happened in 50-60°F weather in NorCal.

@dixiekidd88 if you're in NorCal, consider talking to or bringing your car to Frontier Ford. Mine was the second car they did this fix for, so at this point, it seems like they know what they're doing.

https://www.macheforum.com/site/threads/our-ongoing-nightmare.12075/post-308916

I am in NorCal and I work at a Ford Dealership ? we were visiting fam when it left us stranded, needless to say our surprise visit for Xmas was a huge surprise when we rolled up in a flatbed tow truck.

Was towed to the closest dealer, and has been there since. Hopefully they can figure it out soon, if not we know what we have to do. Just very unfortunate, we love the car!

Thanks for sharing the info I will send a copy of the info to the Ford rep to forward to the dealership, she has been helpful and so has the service advisor. They are doing what they can with limited info….

 

[Blue highway]

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking for thought this was some good info!

thanks for sharing the document.

If I read the document correctly, the high voltage battery only charges the 12v battery when the car is parked AND in the off position AND when the 12v SOC is less than 40% for 48 hours. If the SOC is less than 30% it will not wait 48 hours…. But again the car has to be off AND parked. If you are on an overnight road trip you are SOL.

I now understand why we see cars die because of low 12v battery while being driven.

If the 12v battery state of charge is say 31% and you are driving with the lights on, hvac blower going, stereo playing etc for an extended period (say 5-6 hours fast charging a couple times in a row), then the tiny 35ah battery could easily fall below a level that will keep the modules running and the MORONIC 12v charging design can not cope with this condition.

I now also understand why they hid the 12v battery under the cover…. They don’t want customers charging it or changing the capacity because either of those actions will confuse the 12v battery charging algorithm….

if you do back to back fast charge driving without leaving the car off and parked, the car will stop as soon as the 12v battery is depleted…. If you are starting out at 31% charge that’s only ~4ah away…. Not real far if headlights and blower fan are running….

 

[Logal727]

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking for thought this was some good info!

Wow this is super interesting, all good things to know how it works. Thanks for finding.

 

[Astraea]

Wow this is super interesting, all good things to know how it works. Thanks for finding.

This definitely cleared up pretty much all questions I had about how the system works as it's incredibly clear in the document how it all functions. Just gives me more ideas about how to fix it or work arounds to force the HVB to charge the LVB when it gets low. ?

 

[dtbaker61]

thanks for sharing the document.

If I read the document correctly, the high voltage battery only charges the 12v battery when the car is parked AND in the off position AND when the 12v SOC is less than 40% for 48 hours. If the SOC is less than 30% it will not wait 48 hours…. But again the car has to be off AND parked. If you are on an overnight road trip you are SOL.

THIS cannot be true.

When the car is 'on' with a correctly functioning system, the 12v connection points are at 14+ volts from the dc-dc powering up 12v stuff directly and charging the LVB, which means that the LV battery is being charged whenever MME is 'on'.

If the car is off, sleeping and parked, the system may drop as low as 11.9, but then is checked periodically and supposed to 'wake up' and charge when needed.

The LVB *should* be checked, and charged 'automatically' whether the MME is parked and off, or on and driving. If this is NOT happening, then an module is faulty, or battery is damaged and not accepting a charge.

 

[Blue highway]

I am getting increasingly curious about this.... bad batteries, bad modules, bad dc-dc.... hard to tell, but certainly something popping up way more than acceptable.

The problem may or may not be recorded in ODB2 data, but that's pretty hard for most people to extract. I would SUGGEST that anybody having these issues buy an inexpensive ODB2 unit, capture some data, and perhaps people on the forum can help steer in the right direction.

OR, get a cheap current monitor like an Efergy wireless unit usually used to monitor household current, and see if, when, and how much the LVB is actually getting charged! If you are willing to pull off the 'beauty cover' on the rear and drivers side, and install one of these little guys, it will record current and kWhr fed into the LVB

https://www.amazon.com/Efergy-4-0-Wireless-Electricity-Monitor/dp/B001Q1G4WK/ref=sr_1_1_sspa?

alternatively, get a voltmeter that plugs into the 'power outlet' for $10 or so, and keep an eye on it.... knowing that if it doesn't show 14v while vehicle is on, and at least 11.9 when off, then you are in trouble.

https://www.amazon.com/Zeltauto-Cig...ltmeter/dp/B00VL9JZ0K/ref=asc_df_B00VL9JZ0K/?

It’s bad engineering…. Turns out the LVB is only charged by the HVB when the car is off, parked, and the LVB is below 40% for 48 hours or below 30%… the LVB is not charged when the car is running which is why these failures are happening on the road.

 

[dtbaker61]

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking for thought this was some good info!

I read thru this and it appears written specifically for GT level, which apparently has 220a dc-dc designed to run the extra loads of lights and other 12v loads while driving for Police use.... and was written in Aug.... so I am wondering if it is accurate regarding all the conditions for charging and maintenance of the LVB voltage.

Normal loads in ALL trims *should* be supported by the regular dc-dc and voltage regulator whether the MME is sleeping, or on.

I does suggest that we do NOT want to change the ah capacity of the LVB as all the monitoring parameters are expecting a specific capacity. to estimate life cycles and maintenance.

 

[Blue highway]

THIS cannot be true.

When the car is 'on' with a correctly functioning system, the 12v connection points are at 14+ volts from the dc-dc powering up 12v stuff directly and charging the LVB, which means that the LV battery is being charged whenever MME is 'on'.

If the car is off, sleeping and parked, the system may drop as low as 11.9, but then is checked periodically and supposed to 'wake up' and charge when needed.

The LVB *should* be checked, and charged 'automatically' whether the MME is parked and off, or on and driving. If this is NOT happening, then an module is faulty, or battery is damaged and not accepting a charge.

The Ford document explaining the charge system is in the thread


Conditions where High Voltage (HV) to Low Voltage (LV) Energy Transfer is not supported
When the gear selection is not park (e.g. reverse, neutral, drive, sport etc.) the HV to LV Energy Transfer Feature shall deactivate and/or stop the energy transfer process.
When the ignition status is not key-off (e.g. key-on, remote on etc.) the HV to LV Energy Transfer Feature shall deactivate and/or stop the energy transfer process and reset lock out period.
When OTA update is in the process with a software update (non-interruptible state), the HV to LV Energy Transfer Feature shall proceed after the Over the Air (OTA) software update is complete.
When HV to LV Energy Transfer Feature is in the process of an energy transfer, the OTA update shall stop the energy transfer and proceed with the OTA software update.
When an internal error and/or fault is detected (e.g. HV to LV DTC etc.) the HV to LV Energy Transfer Feature shall immediately deactivate and/or stop the energy transfer process.
The HV to LV Energy Transfer Feature shall be enabled to provide energy transfer when vehicle is in “customer mode” or “transport mode”. The feature shall be disabled in all other lifecycle modes.
The customer shall be notified in the vehicle and/or mobile app of the HV to LV Energy Transfer Status if the HV to LV Energy Transfer Feature occurred because of battery consumption conditions (battery EOL, high KOL, park lamps active, hazard lamps active).
- The 12V battery needs to power modules and close the HV battery contactors upon key-on.
- If the 12V battery is depleted (very low SOC), it will not be capable of performing this function. With no ability to close the

 

[Crilly]

Full accessories power well drain the 12 volt battery pretty quick.

 

[SnBGC]

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking for thought this was some good info!

Fascinating document! Will read again when I have access to a larger screen. I wonder what the difference is between energy transfer and charging?

Sounds like turning on the hazard lights forces energy transfer?
Interesting.....

 

[sockmeister]

THIS cannot be true.

When the car is 'on' with a correctly functioning system, the 12v connection points are at 14+ volts from the dc-dc powering up 12v stuff directly and charging the LVB, which means that the LV battery is being charged whenever MME is 'on'.

If the car is off, sleeping and parked, the system may drop as low as 11.9, but then is checked periodically and supposed to 'wake up' and charge when needed.

The LVB *should* be checked, and charged 'automatically' whether the MME is parked and off, or on and driving. If this is NOT happening, then an module is faulty, or battery is damaged and not accepting a charge.

I've noticed that too. The voltage jumps to around 14 when the car is "On", and it's back to 12.6ish when off.
The regular trim Mach-Es definitely seem to be charging the 12v, at least slowly, as long as the car is running.

 

[sockmeister]

Okay! So I found this PDF and it looks like Ford doesn't recommend a change in LVB even with the extra accessories that would be using it. They do go into depth about the charging of the LVB from HVB so worth the read for some extra clarified information about the system. I'll keep looking, thought this was some good info!

It's interesting that they recommend against any trim level besides GT, due to the inadequacy of the 12v battery to handle additional loads on non-GT trims.
Do the GT trims have a higher capacity LVB from the factory? And if so, what's the reason?

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