Mach-e dead again

[chrisGT]

Sat 8 days 17th to 26th. Plugged in a new Christmas present and this is what I got.

After 8 days the 12V started at 75% and charged to 91% when powered on (started). Appears the battery is taking a charge now. Wondering if it sat for two weeks if it would be below 75%?

Does anyone know what is normal while sitting and at what % sync will charge the 12V battery or does it not maintain the 12V when parked? Appears the battery health is better to test it again. Hoping the battery was the cause not a symptom. Time will tell.

Best to all for the new year.

Mine was 64% after being parked for less than 24hours. I drove 25 mins and it went up to 70%. Then I parked again and within half an hour it was down to 65%.

 

[Shayne]

Mine was 64% after being parked for less than 24hours. I drove 25 mins and it went up to 70%. Then I parked again and within half an hour it was down to 65%.

Thank you for your confirmation. Mine sat started plugged to 240V for the 30 minutes to get a new battery up 15% to 90%.

12V maintenance logic under different states? Would be nice to be educated on this new tech a bit. Thought educating the users was part of it? How does it sitting at 65% make you feel about taking off on a trip? Think that is in spec? Maybe it does not kick on and charge it to 90% until it hits 60%? Maybe mine got drained below 11.8V and killed the first one? Time will tell I think.

I have been informed defective battery after 10 months and it got cold. Possible. Not too worried but will now be looking before I take off on any distance again. Forgetting about it and letting it sit; it is getting cold here. Ford has being good at trying to fix hiccups. There has been a few for me now.

 

[louibluey]

Thank you for your confirmation. Mine sat started plugged to 240V for the 30 minutes to get a new battery up 15% to 90%.

12V maintenance logic under different states? Would be nice to be educated on this new tech a bit. Thought educating the users was part of it? How does it sitting at 65% make you feel about taking off on a trip? Think that is in spec? Maybe it does not kick on and charge it to 90% until it hits 60%? Maybe mine got drained below 11.8V and killed the first one? Time will tell I think.

I have been informed defective battery after 10 months and it got cold. Possible. Not too worried but will now be looking before I take off on any distance again. Forgetting about it and letting it sit; it is getting cold here. Ford has being good at trying to fix hiccups. There has been a few for me now.

In @Mach-Lee 's thread, How to Recondition/Service Your 12V Battery, he posted the graph below showing voltage vs. soc. Use of the graph is a little difficult, because when the MME is first opened, lots of small loads come on which cause the voltage to be a lower, loaded voltage. Waiting until the frunk light goes off seems to be the best indicator of a good time to measure. (keep the fob and phone away, so MME does not come on). The 12V negative cable could also be lifted for a while too, but clearly that is a pain (10mm socket if you want to try it, keep something handy like a glove or towel to keep it from falling back onto the negative terminal, or tape it to the stiffening bar above).

The consensus to date appears to be that MME turns on the DC/DC converter (my tests were MME not plugged in) between about 11.9V and 12.1V (more report 12.1V). From the graph below, that is below 40%. Others have reported MME self charging back to 90% from there.

Clearly the care and feeding of the LVB is not working correctly in some MME, seems most common lately in the GT. Not clear yet if it is damaged batteries, or a software issue. With Ford and so many of us looking at the issue (some by finding discharged or "dead" LVB), I imagine the fix will follow soon, just like in the first round early 2020.

This is not for everyone (and you shouldn't have to do it), but if you are a DIY type, try to recondition your battery according to How to Recondition/Service Your 12V Battery. You don't need the lab gear I have access to, but I can report from my testing that despite the warnings I was getting, my one year old LVB reconditioned back to new with little effort (so it was not damaged).

 

[JimmyMachE]

The consensus to date appears to be that MME turns on the DC/DC converter (my tests were MME not plugged in) between about 11.9V and 12.1V (more report 12.1V). From the graph below, that is below 40%.

The 12 V battery BMS uses a more elaborate method for calculating SOC, based not only on voltage under recent load, but several other factors.

The % SOC of the 12V battery (value calculated by MME) is readable through obd port, as already mentioned by other members.

 

[louibluey]

The 12 V battery BMS uses a more elaborate method for calculating SOC, based not only on voltage under recent load, but several other factors.

The % SOC of the 12V battery (value calculated by MME) is readable through obd port, as already mentioned by other members.

Correct, and probably some what cumulative, which is why likely why Ford wants you to reset the BMS when changing the battery. But, note that BMS goes to sleep often. The latest BMS values may be old. The second X-Y plot here shows that MME off (this case was L2 plugged in), BMS sleeps a lot.

Measuring as above gives a "real-time" look at the LVB now.

 

[JimmyMachE]

Actually the BMS probably never goes to sleep, it even measures the standby drain in a locked car (quiescent average), which is readable with Car Scanner app.

In ICE Fords the standby drain of the 12V battery is measured every few minutes or so (as far as I remember).

 

[louibluey]

Actually the BMS probably never goes to sleep, it even measures the standby drain in a locked car (quiescent average), which is readable with Car Scanner app.

In ICE Fords the standby drain of the 12V battery is measured every few minutes or so (as far as I remember).

At least on my FE, Dec 20, LIN Bus #4 (which includes the BMS) is commanded to go to sleep shortly after MME is turned off. In some cases BMS wakes for a short period every 15 minutes. I am literally monitoring LIN Bus #4 with a CANedge2 LIN monitor as described in the link above.

 

[Shayne]

In @Mach-Lee 's thread, How to Recondition/Service Your 12V Battery, he posted the graph below showing voltage vs. soc. Use of the graph is a little difficult, because when the MME is first opened, lots of small loads come on which cause the voltage to be a lower, loaded voltage. Waiting until the frunk light goes off seems to be the best indicator of a good time to measure. (keep the fob and phone away, so MME does not come on). The 12V negative cable could also be lifted for a while too, but clearly that is a pain (10mm socket if you want to try it, keep something handy like a glove or towel to keep it from falling back onto the negative terminal, or tape it to the stiffening bar above).

The consensus to date appears to be that MME turns on the DC/DC converter (my tests were MME not plugged in) between about 11.9V and 12.1V (more report 12.1V). From the graph below, that is below 40%. Others have reported MME self charging back to 90% from there.

Clearly the care and feeding of the LVB is not working correctly in some MME, seems most common lately in the GT. Not clear yet if it is damaged batteries, or a software issue. With Ford and so many of us looking at the issue (some by finding discharged or "dead" LVB), I imagine the fix will follow soon, just like in the first round early 2020.

This is not for everyone (and you shouldn't have to do it), but if you are a DIY type, try to recondition your battery according to How to Recondition/Service Your 12V Battery. You don't need the lab gear I have access to, but I can report from my testing that despite the warnings I was getting, my one year old LVB reconditioned back to new with little effort (so it was not damaged).

Thank you for the info. November 2020 build here so not GT. Maybe GT owners are more in tune? My battery is brand new so no reconditioning is required at this stage. Why would you need to recondition a 1 year old battery? I would assume it would come back brand new. 11.8 V is the critical line so not coming on until 11.9V (many 12.1) makes little sense to me. I would of thought it should never drop below 80%. It is plugged in to 240V so why would it be sitting at 40%? Not too much room for any error or hiccup when it is sitting at that SOC.

 

[Mach-Lee]

At least on my FE, Dec 20, LIN Bus #4 (which includes the BMS) is commanded to go to sleep shortly after MME is turned off. In some cases BMS wakes for a short period every 15 minutes. I am literally monitoring LIN Bus #4 with a CANedge2 LIN monitor as described in the link above.

I think the chip in the BMS stays active 24/7 and continuously measures current draw, but only communicates on the LIN bus when the car is awake. I believe the chip can update its SoC reading while it's in standby and communicates that to the car during the next scheduled wake period.

Have you tested if pulling a large draw wakes up the LIN bus early?

 

[JimmyMachE]

At least on my FE, Dec 20, LIN Bus #4 (which includes the BMS) is commanded to go to sleep shortly after MME is turned off. In some cases BMS wakes for a short period every 15 minutes. I am literally monitoring LIN Bus #4 with a CANedge2 LIN monitor as described in the link above.

Very interesting research, thanks for your efforts.

I am not expert in the field, so just a working hypothesis - BMS is not active on LIN as other units go to sleep, yet BMS might still monitor the battery current/voltage and store data internally, to be retrieved periodically or when car is opened.

A bit like the aftermarket BM2 bluetooth adapter installed on 12V battery to constantly monitor battery voltage, causing almost no extra drain (1mA according to spec). Collected data is retrieved later via bluetooth from BM2.

12V BMS sensor is used in ICE Fords, maybe FDRS or Forscan contain more details or parameters?

My standby drain is between 18mA and 30mA in Car Scanner.

 

[chrisGT]

I had a long trip on Friday and rerurn trip on Saturday. Each time the car was ON for about 4hours. I did not even turn it off for fast charging.
The 12v battery SoC went from 65%(before the trip) to almost 100%.
Today it was 87% after being parked for 14 hours. The car was charging the big battery half of the time. Garage temperature was in the low 40s F.
It looks like the 12v battery does not hold its charge at a high level for too long. I am not sure if this is because of the battery not being in great condition or the parasitic drain of the car.

Ps. Btw my GT got about 220 highway miles with a full charge each time. I find this disappointing. Exterior temps were 38-40 and heater was set to 71 and climate control used 9% of total (about 20 miles). So the problem is not just the missing heat pump. The powertrain is inefficient at high speeds.

 

[JimmyMachE]

The 12v battery SoC went from 65%(before the trip) to almost 100%.
Today it was 87% after being parked for 14 hours.

Do you lock the car when parked? What is your standby drain (quiescent)? Value can be read with Car Scanner app.

 

[Shayne]

I had a long trip on Friday and rerurn trip on Saturday. Each time the car was ON for about 4hours. I did not even turn it off for fast charging.
The 12v battery SoC went from 65%(before the trip) to almost 100%.
Today it was 87% after being parked for 14 hours. The car was charging the big battery half of the time. Garage temperature was in the low 40s F.
It looks like the 12v battery does not hold its charge at a high level for too long. I am not sure if this is because of the battery not being in great condition or the parasitic drain of the car.

Ps. Btw my GT got about 220 highway miles with a full charge each time. I find this disappointing. Exterior temps were 38-40 and heater was set to 71 and climate control used 9% of total (about 20 miles). So the problem is not just the missing heat pump. The powertrain is inefficient at high speeds.

Interesting tests by @louibluey here he has a thread started now here. Initial results indicate the logic lets the 12V drain to near 30% soc before it attempts to charge it. Hoping there is not a huge parasitic drain when at 30% but it is possible with the car in a certain state? There are a lot of states; last February it was right after charging from what I understood and a contact problem. Your 87% has 57% to go before it gets a charge or another 60 hours based on the first 13%. What was the voltage at 100% that may hint on health?

P.S. I am around the 250 mile range for 65 mph @ 68F with a premium awd so your GT sounds about right. Mine is pretty close to what the EPA numbers stated. I have found if I can make the charging stations I have plenty of range. The new DCFC curve is good enough here that I no longer have math base range anxiety. I can get it to 100% at a DCFC @-10F. Charging schedule now works, range now works at DCFC's ............... now if these 12V's could quit dying on me I am all set . Guesstimates based on epa of an MME 4x. I think if we drive no faster than 50 mph we are all set .

 

[chrisGT]

60mA is

Do you lock the car when parked? What is your standby drain (quiescent)? Value can be read with Car Scanner app.

60mA is the standby drain with the car off and locked. I always lock the car, the key fob is far away and I don't have PAAK set up. There is nothing plugged in.

The state of charge is 12v SOC is 72% today after sitting for about 16 hours. It was 90% when I parked 16 hours ago.

 

[Shayne]

Was going to wait a week but after parked 6 days FP crapped out on me so thawed it out this morning as temps went up to -5C (23F). It has been cold the last week never above 0C (32F) with a constant daytime around -10C (14F) dipping to -28C (-18F) for the last 6 days. Plugged into 240V and saw it pulling power for over 2 hours out of schedule and not charging ?. Not following it too closely and do not care how much it needs. This morning 12V started over 13V, 90% soc and went up to 96%. Feeling better every week.

Just a few ups and downs not sure if it is the app?

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