12v battery charging

[tim49]

I am confused. My dealer told me that the car could be left for 3 months as the 12v battery would automatically be charged from the main battery pack, and as long as that had sufficient charge there would not be a problem. Reading some of the threads this seems to be nonsense. Does anyone know what the position is with newly built Mach e's? Should I put it on a trickle charge every 2/3 weeks?

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[generaltso]

I am confused. My dealer told me that the car could be left for 3 months as the 12v battery would automatically be charged from the main battery pack, and as long as that had sufficient charge there would not be a problem. Reading some of the threads this seems to be nonsense. Does anyone know what the position is with newly built Mach e's? Should I put it on a trickle charge every 2/3 weeks?

If the car is functioning properly, there is no need to trickle charge the 12V battery. Some people’s cars are not working properly. That being said, Ford does recommend disconnecting the 12V battery if the car will be stored for more than 30 days.

 

[tim49]

If the car is functioning properly, there is no need to trickle charge the 12V battery. Some people’s cars are not working properly. That being said, Ford does recommend disconnecting the 12V battery if the car will be stored for more than 30 days.

So to be clear, the main EV battery keeps the 12v battery charged. I understand disconnecting the battery is not easy, and the bonnet needs the power to open. Sorry these questions are probably obvious but it is amazing how little the dealers know.

 

[generaltso]

So to be clear, the main EV battery keeps the 12v battery charged.

If everything is functioning properly, that's correct.

 

[tim49]

If everything is functioning properly, that's correct.

Thank you very helpful

 

[RickMachE]

If you're not driving it for 3 months, in addition to disconnecting the 12v battery, you want the state of charge on the HVB to be about 50%.

 

[Shayne]

If the car is functioning properly, there is no need to trickle charge the 12V battery. Some people’s cars are not working properly. That being said, Ford does recommend disconnecting the 12V battery if the car will be stored for more than 30 days.

Disagree some people live in colder climates and the car is working as it was designed for all but as it was designed is not working in the colder climates is what I would say. Saying it is a problem for only a few or that those particulate cars are not working properly I would say is inaccurate. If you live in Vermont you have a better chance of not exposing the problem but in no way does it indicates it does not exist.

 

[generaltso]

Disagree some people live in colder climates and the car is working as it was designed for all but as it was designed is not working in the colder climates is what I would say. Saying it is a problem for only a few or that those particulate cars are not working properly I would say is inaccurate. If you live in Vermont you have a better chance of not exposing the problem but in no way does it indicates it does not exist.

I didn't say the problem doesn't exist. There are an alarming number of people reporting dead 12V batteries. In those cases, something is not working as designed. Are you saying that your car and all the others with repeated 12V issues are working as designed?

It has been -10F to -15F for much of January in Vermont. My 12V battery often gets low in those temperatures, which generates the 12V fault warning and kicks on the DC/DC converter to bring the voltage back up. That's how it's supposed to work (except for the horrible wording in the fault message).

 

[Shayne]

I didn't say the problem doesn't exist. There are an alarming number of people reporting dead 12V batteries. In those cases, something is not working as designed. Are you saying that your car and all the others with repeated 12V issues are working as designed?

It has been -10F to -15F for much of January in Vermont. My 12V battery often gets low in those temperatures, which generates the 12V fault warning and kicks on the DC/DC converter to bring the voltage back up. That's how it's supposed to work (except for the horrible wording in the fault message).

Charge fault message here and 12V slushy I think. Nothing kicking on or working right after a few days of it sitting in the cold.

I think based on @louibluey test and others it appears the MME lets the 12V go down to 40% soc before it decides to charge it. At that state of charge I would say the 12V's are freezing. The car comes on and charges the 12V so the hardware is working and most likely as designed. I saw mine down to 62% today which at these temps is not sound. Revised logic that uses a temperature sensor and adjust the minimum soc may solve my problem. I think my hardware is good but 40% soc logic is not. Only a problem below -15F. Let it sit in those temps for 3 to 4 days and do not touch it should do it for you if you are looking for a died 12V.

As the mountain descent problem in Europe it was not only those cars that had a problem as it started to show up in Colorado also. Thinking it was those cars in Norway that were put in that situation first. Drive it every day you may not trigger my problem since as soon as you start it it overrides the 40% and starts charging it right away. Have no idea if all are related here. My car functions no problems above freezing but sits like crap as soon as it gets cold. Posted the image below a number of times here your comments are appreciated. Think it sitting at 45% soc in the cold is a good idea?

Also I lost 30% soc on the 12V battery in a little over a day today just sitting there in a deep sleep? No other car I have owned sucks down a 12V like that or even needs to come on and charge itself regularity. My truck can sit a month on a new battery no problems. What appears to be a large drain would not matter if it was not sucking it down to 40% in a few days.

 

[louibluey]

Charge fault message here and 12V slushy I think. Nothing kicking on or working right after a few days of it sitting in the cold.

I think based on @louibluey test and others it appears the MME lets the 12V go down to 40% soc before it decides to charge it. At that state of charge I would say the 12V's are freezing. The car comes on and charges the 12V so the hardware is working and most likely as designed. I saw mine down to 62% today which at these temps is not sound. Revised logic that uses a temperature sensor and adjust the minimum soc may solve my problem. I think my hardware is good but 40% soc logic is not. Only a problem below -15F. Let it sit in those temps for 3 to 4 days and do not touch it should do it for you if you are looking for a died 12V.

As the mountain descent problem in Europe it was not only those cars that had a problem as it started to show up in Colorado also. Thinking it was those cars in Norway that were put in that situation first. Drive it every day you may not trigger my problem since as soon as you start it it overrides the 40% and starts charging it right away. Have no idea if all are related here. My car functions no problems above freezing but sits like crap as soon as it gets cold. Posted the image below a number of times here your comments are appreciated. Think it sitting at 45% soc in the cold is a good idea?

Also I lost 30% soc on the 12V battery in a little over a day today just sitting there in a deep sleep? No other car I have owned sucks down a 12V like that or even needs to come on and charge itself regularity. My truck can sit a month on a new battery no problems. What appears to be a large drain would not matter if it was not sucking it down to 40% in a few days.

Maybe try to write a letter to Ford engineering? Might take some googling to find an address or email address for an actual engineer in that area.

With the new AC Delco battery, I am seeing cycling now down to 35%. Not sure if something changed in my BMS, or if MME really is deeper cycling because of 50 Ah vs. 35 Ah. Just a note, I understand that is the opposite of what we want. I ordered a new BMS to rule out the bms.

I would cycle the LVB at 70% or 80%, not sure why the go so deep, unless it was just a charge discharge philosophy similar to using the large traction battery. I guess there would be more contactor operations of the positive and negative aux contactors, no sure if that is an issue or would factor into why they go so low. OTOH, if they were in the just in the mode of thinking how we use the HVB, 40% may have seem okay to them.

 

[TheVirtualTim]

While many modules shut down when the car is off, there are some modules that have to remain powered up and working. After some period of non-use the car may go into "deep sleep" mode ... which powers off a few more modules to save more power.

But any modules that remain up are getting their power exclusively from the 12v battery ... so it does have a constant (but slow) drain on it. There is a module that monitors the 12v state of charge. That module is responsible for recharging the 12v battery when needed.

If the car is plugged in, it will charge the 12v using the AC power.
If the car is NOT plugged in, it will connect the high-voltage battery and use that to charge the 12v.

I do not know what at what specific voltage level it will decide to charge ... only where it plans to get the power for the charge.

 

[Shayne]

Maybe try to write a letter to Ford engineering? Might take some googling to find an address or email address for an actual engineer in that area.

With the new AC Delco battery, I am seeing cycling now down to 35%. Not sure if something changed in my BMS, or if MME really is deeper cycling because of 50 Ah vs. 35 Ah. Just a note, I understand that is the opposite of what we want. I ordered a new BMS to rule out the bms.

I would cycle the LVB at 70% or 80%, not sure why the go so deep, unless it was just a charge discharge philosophy similar to using the large traction battery. I guess there would be more contactor operations of the positive and negative aux contactors, no sure if that is an issue or would factor into why they go so low. OTOH, if they were in the just in the mode of thinking how we use the HVB, 40% may have seem okay to them.

Car drew power grizzl-e flashing and charging port on from 6am (woke up) to about 3pm today. Went out after it stopped and the LVB was at 94% soc ?. Never started the vehicle just opened and inserted the dongle when off. When I pulled the dongle and walked away guess what it is drawing power again (another couple of hours)? The car comes on and maintains the 12V so you would assume they should be able to be modified to the logic it comes on at if required. I am not sitting around the table and one of the design engineers may quickly say we have accounted for that you silly bugger? Just brain storming on a problem I have; throwing ideas out there no matter how silly they may sound. Unless there are a whole lot of ford reward points in the equation I'm out ?.

It is plausible by the fact that it is occurring in cold temps, your observations that the car lets the 12V go to very low discharge levels such the 12V's are getting slushy and triggering the contactor not to close. Thinking that may be a cheaper fix than new BECM and HV junction box which may not even help in my case. Car runs great just this one hiccup. Sounds like you may think plausible also or you want to see me being called a silly bugger.

Some days it draws powers for hours and sometimes nothing at all letting it go down to 60% in cold sub-zero temps! Draws a lot doing nothing which does not help. Low tonight -28C with 94% soc on the 12v (baring any huge drain) I am betting it will make it to tomorrow morning. Need this fixed. I do not think too many can keep machines alive and running like some so kind of thinking it has to happen?

While many modules shut down when the car is off, there are some modules that have to remain powered up and working. After some period of non-use the car may go into "deep sleep" mode ... which powers off a few more modules to save more power.

But any modules that remain up are getting their power exclusively from the 12v battery ... so it does have a constant (but slow) drain on it. There is a module that monitors the 12v state of charge. That module is responsible for recharging the 12v battery when needed.

If the car is plugged in, it will charge the 12v using the AC power.
If the car is NOT plugged in, it will connect the high-voltage battery and use that to charge the 12v.

I do not know what at what specific voltage level it will decide to charge ... only where it plans to get the power for the charge.

There is the man. It would be great if you could elaborate on That module is responsible for recharging the 12v battery when needed.

Can you dig up the definition of when needed? At what specific voltage level it will decide to charge. Is that a function of temperature or does it just drain it to 40% soc regardless of how cold it is?

 

[Shayne]

My post above was a quote to another that has now been modified. Also the post I quoted has been deleted. I understand you can delete your posts but did not think you could modify others and delete quotes from theirs. Unless of course the modifications are being carried out by the administration without members knowledge or consent which would is highly questionable.

 

[macchiaz-o]

My post above was a quote to another that has now been modified. Also the post I quoted has been deleted. I understand you can delete your posts but did not think you could modify others and delete quotes from theirs. Unless of course the modifications are being carried out by the administration without members knowledge or consent which would is highly questionable.

If that's happening, I'd be quite upset, too.

The other "club" was definitely doing this to my posts, even fully deleting them without letting me know. Once I noticed I stopped contributing to their forum.

Are you sure posts you quoted were removed? Try loading this page with an InPrivate/Incognito browser tab. It could be that the other person added you to their block list.

 

[Shayne]

If that's happening, I'd be quite upset, too.

The other "club" was definitely doing this to my posts, even fully deleting them without letting me know. Once I noticed I stopped contributing to their forum.

Are you sure posts you quoted were removed? Try loading this page with an InPrivate/Incognito browser tab. It could be that the other person added you to their block list.

@Kamuelaflyer sorry dude. Ranting up here in the cold.

Ya there is something going on here since if I log out I get this

If I log in I get this

But here are my settings? Blocking does not block their quotes by others. You see them? I don't block I skip.