Lots of talk about SOC 12V Bat.

[SonicBlue]

It is my belief that it is because Ford has deliberately made it so that HVB will first the LVB charges at around 30- 40% SOC, which thus destroys the LVB battery prematurely, instead of keeping the LVB charged from the HVB between 80 and 100% (This gives flow in product sales, now that the oil does not have to be changed, as with petrol cars about 3000 miles) because electric cars do not require so much maintenance, Which the dealers are not happy about.

But i do love the car, and think it is the coolest electric car bye fare on the market when you compare prices for another electric car. And love the interior ?

Of course, that's just my opinion?

I sometimes think there’s a bit of mass hysteria on this board, too. The HVBJB issue, for example, was very serious but relatively rare. But it was calamity on this board.

But I’ve seen more than enough people posting about LVB issues, plus my own multiple experiences even though I’m a daily driver, to know that the LVB charge management appears to be a widespread problem.

At this point, telling people to “just drive” is borderline misinformation. Especially when the fix is usually pretty easy: charge the car.

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[Mach-Lee]

I have a 2021 MME with 38,000 miles. I plug it into my home level 2 charger whenever I am not using the car. I get this error message about once a week, so often that I now ignor it. I have brought the car to the dealer about 5 times now and asked them to look into this. Each time they say they did a software upgrade to fix it, then I get the same message a day or two later.

I love the car and it runs great, but these messages are a bit anoying. Does anyone know how to fix this?

Silver pony.

You may have a drain or poorly calibrated BMS, see this for troubleshooting: https://www.macheforum.com/site/thr...-system-drain-service-required-message.36140/

 

[profdraper]

I sometimes think there’s a bit of mass hysteria on this board, too. The HVBJB issue, for example, was very serious but relatively rare. But it was calamity on this board.

But I’ve seen more than enough people posting about LVB issues, plus my own multiple experiences even though I’m a daily driver, to know that the LVB charge management appears to be a widespread problem.

At this point, telling people to “just drive” is borderline misinformation. Especially when the fix is usually pretty easy: charge the car.

Sure. & that in essence is social media … ‘the wisdom of crouds’ [not]. The UK fora are near unbearable.

Having said that, there always special cases & some of the true experts on this form have been just brilliant in helping out. Mach-Lee for one. Thanks.

 

[profdraper]

Being a new owner of a Mach-E, how does one keep the 12V batterie charged, what is/are the best practices?
If I have the car plugged in (with a 48amp charger) and the traction batterie is charged to 80 or 90% (max), which at that point the charge rate drops to a trickle (which it does), does that also keep the 12v batterie charged?
Do you have to drive it to keep the 12v batterie charged?
Will the OTA software install while the car is plugged in?

I went with one of these for piece of mind, seems quite accurate & I just plug into the cigarette lighter from time to time - when the car is off OR when running.
https://www.innova.com/products/battery-monitor-3721

In practice I find that driving the car regularly does the job. I’d probably be monitoring more closely if it were garaged all week. Also charging at home regularly does the trick.

 

[MailGuy]

A more useful approach might be to suggest there are some perceived issues in the 12v system that can be addressed by ‘x, y, z etc’.

You missed the entire point of my reply. Managing a 12v battery on the MachE should NOT be necessary, but you may encounter issues. No snark, but it is responses criticizing other members that have caused me to read this forum less and less.

 

[medriver]

The 12V battery is not perfect. Mach-Lee has a thread on it but its thorough. Essentially the way the car works is the battery only charges when the HVB in engaged and NOT fast charging, so when driving or when charging using the inverter.

The when functioning nominally goes to sleep and conserves battery decently. When it "wakes up" it can use a few percent of the 12v battery (computer, puddle lights, car lights, etc), you can wake it up through fordpass or walking by with a key. My key functions pretty well and unless I am pretty close to the car it doesn't cause a wakeup and the car start to ignore the key after a while.

One of the problems is that I would assume with PAAK, Bluetooth is relatively bad at calculating ranges and i would assume (i used paak for 1 day)that can and probably does wake up the car at unpredictable ranges.

If you open ford pass and look at the car a bajillion times, 12v battery drain.

If you don't drive much and frequently charge at 48 amps, 12v battery may not top off properly.

There is a safety mechanism where if the 12v battery goes low enough it'll slug it from the HVB, the only problem with this is when the charge on an AGM battery gets too low it'll suffer from sulfation and be damaged, so your 12v can sit at just low enough to be damaged but high enough to not be proactively charged by the hvb through salvage, leading to battery failure.

There are other factors such as a drain from a device such as a dashcam, etc.

Ultimately drive the car and charge it as slow as is practical and avoid unnecessary wakeups and it should not be a problem, i.e. the majority of people.

This is why ford is so restrictive about fordpass integrations because it can really mess up the car.

 

[rreddy3]

You missed the entire point of my reply. Managing a 12v battery on the MachE should NOT be necessary, but you may encounter issues. No snark, but it is responses criticizing other members that have caused me to read this forum less and less.

Precisely what useful, actionable, advise did you give OP in your response to him?

 

[JJR]

Being a new owner of a Mach-E, how does one keep the 12V batterie charged, what is/are the best practices?
If I have the car plugged in (with a 48amp charger) and the traction batterie is charged to 80 or 90% (max), which at that point the charge rate drops to a trickle (which it does), does that also keep the 12v batterie charged?
Do you have to drive it to keep the 12v batterie charged?
Will the OTA software install while the car is plugged in?

Questions, Questions, Questions

George M

I struggled with this issue because I drive very little. 2022 with 1700 miles with 1000 the first six months. I was getting 12v battery fault messages frequently.
The first thing I did was install an Ancel 12v Battery Monitor. It attaches to the 12v battery and connects to an app on my phone via bluetooth. I had to remove the Frunk tub to get at the 12v battery.
Now when the battery needs charging, about once a week, I turn on the car and let it idle in my garage for 10 or 12 hours. This requires me to turn off the auto shut off setting which is under the Vehicle tab.
This costs me about 2% or 3% of HVB charge.
Since I've been doing this I haven't received any 12v battery fault messages.
There's no reason this can't be done without the Ancel, just remember to run the vehicle once a week.

 

[Space_Pony]

It seems you could also just go on a drive for an hour or so once or twice a week and enjoy the car

 

[JJR]

I struggled with this issue because I drive very little. 2022 with 1700 miles with 1000 the first six months. I was getting 12v battery fault messages frequently.
The first thing I did was install an Ancel 12v Battery Monitor. It attaches to the 12v battery and connects to an app on my phone via bluetooth. I had to remove the Frunk tub to get at the 12v battery.
Now when the battery needs charging, about once a week, I turn on the car and let it idle in my garage for 10 or 12 hours. This requires me to turn off the auto shut off setting which is under the Vehicle tab.
This costs me about 2% or 3% of HVB charge.
Since I've been doing this I haven't received any 12v battery fault messages.
There's no reason this can't be done without the Ancel, just remember to run the vehicle once a week.

The "auto shut off setting" is the Power down Timer.

 

[Jgg181]

Maybe I am singularly annoyed by this…but does anyone know why Ford stopped displaying the 12v battery SOC in the website, and/or not include the SOC in the Fordpass recent update?

 

[Snakebitten]

Soon after acquiring my 2023.5 GTPE, and joining the forum, I saw all the AGM angst documented here.
I thought I'd prepare to address it before it ever became an issue for me. I immediately installed a Bluetooth voltmeter to make sure a low SOC didn't catch me by surprise.

Alas I've so far had nothing to worry about. I suspect Ford's latest version of lvb management/charging strategy is superior to what was in place the first few years?

It coincides with a similar anemic lvb charging strategy that the Powerboost F150 was released with. Those trucks have thread after thread listing the problems a low SOC causes. But about 6 months ago, FDRS had a fresh update that drastically improved the charging and target SOC during normal use.

I still monitor the SOC/Static-resting Voltage on both vehicles. But they both are just fine and neither require any extra effort on my part to keep them healthy.

 

[lesz]

I struggled with this issue because I drive very little. 2022 with 1700 miles with 1000 the first six months. I was getting 12v battery fault messages frequently.
The first thing I did was install an Ancel 12v Battery Monitor. It attaches to the 12v battery and connects to an app on my phone via bluetooth. I had to remove the Frunk tub to get at the 12v battery.
Now when the battery needs charging, about once a week, I turn on the car and let it idle in my garage for 10 or 12 hours. This requires me to turn off the auto shut off setting which is under the Vehicle tab.
This costs me about 2% or 3% of HVB charge.
Since I've been doing this I haven't received any 12v battery fault messages.
There's no reason this can't be done without the Ancel, just remember to run the vehicle once a week.

I also drive infrequently and have had problems with a too low SoC for the LVB. Charging at L1 works for me - it takes long enough to reach my target SoC for the HVB the my 12v gets charged adequately.

 

[dtbaker61]

In my opinion, the 12v battery in the MachE is the most under engineered component in the car. Over 16 years I have owned 5 electric or hybrid vehicles with combined mileage over 700,000 miles. All but one have used Li Ion 12 v batteries. Only one of those Li Ions was replaced after 10 years of use and that was mostly user error on my son's friends fault. I honestly never paid attention to the 12v system. It just worked, or still works in two of the cars I still own. Not so with the MachE. The AGM in the MachE failed after 42 months and 30,000 miles.

The AGM in the Mach-e has a 36mo warranty, I got 40mo, you got 42m... that pretty good. I think a proactive Dealership should be contacting owners at 35mo and off 'free testing' .... and have a replacement sitting on the shelf for all vehicles over 36mo

 

[N1naz]

Ok So this was my first experience monitoring the 12V battery.

Before my latest trip I measured the 12v bat SOC to be 97% (at 13.3v) using an OBD2 scanner with the MME just unplugged (after ~36h not driven but pluged in and at 100% SOC, I do this about once a month. (The 100% part)).
After a ~1.5-hour trip (48 miles) both highway and side roads. The reading after pulling into my driveway was the same before and after shutting the MME down 92% 13.1v (rounding of the OBD2 or system, don’t know exactly what the voltage should be at 92%).
Plugged in the MME at a charge rate of ~3Kw (16amps) and a max SOC to 90% for the HV Bat. I lowered my “charger” from 48A to 16A to extend the charging time. Approx. 1.5-2 hours. After that time, the 12v battery showed 97% at 13.3 Volts.
My take is a slower charge rate is a benefit to the 12v battery and unless you need the car right away for a long-distance trip, charge at a lower rate for a longer time to give the 12v battery a chance to charge.

Obviously one trip does not prove anything and your milage my vary, but I will continue monitoring and report back.

Why it drained while driving is another mystery. Maybe it needs to get down to a certain SOC before the BMS says time to charge, other than the “40-50%” SOC emergency charging.

Just my observations

George

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