Down for the count :(

[Socalsp3]

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 seems HV to LV charge is only during parking. They may not want the DCDC converter regularly working or regular external demands on HVB while driving. They probably didn't foresee the LVB being deconditioned during shipment delays and draining and dying during driving when it is not getting charged. This doesn't happen in ICE because of alternator. They need to enable LVB charging while driving when SOC is below a certain level.

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[Timelessblur]

With all the issue of the LVB I am surprised ford did not do what some other manufacturers have done. That is in the car put an override button that forces power from the HVB to the DCDC converter to power on the car. Once the car is turned on then LVB is not exactly needed. Mind you if you have to hit the override button to often then you clearly need to get that battery replaced. Hell that button should only be hit a few times at most between battery replacements. And ideally never hit at the car should send a warning it is seeing issues with the LVB.

 

[MachTri]

This happen to me this morning. The two red battery indicators were illuminated when I tried to boot up the car. I turned it off and tried again. I turned it off, opened the door. Waited until everything shut off, tried again, same thing. So I plugged my Ford 240V Charging cable back in. Waited until the 4th circle light started blinking. Then unplugged it (after like 30 seconds). Got back in and it booted up fine. Dropped off my dogs with my daughter (about 40 min drive) car stopped and started properly. Then drove 30 min to work and plugged it into the L2 charger. Fingers crossed.

It sat outside all day yesterday because I was working from home. I don't have a garage but it stays plugged into my L2 charger. Air Temperatures yesterday (Jan 12) were 20F - 45F it was 28F when I tried to start this morning.

I don't know if that bit of incantation will work for everyone or not. Next time I'll use @tonesto7 amazing script to see what the 12V batter says.

Maybe related: It was supposed to be doing a preconditioning to be ready at 7:00 am. At 6:45 I decided I was leaving early so I hit the Charge to 100% and turned started the car through the Fordpass app -- Theory being that charging above the 95% level I had set and heating the cabin would approximate an immediate precondition. The fordpass app said that the remote start succeeded and it was charging to 100%. However as I was puttering around in the cottage getting the dogs ready, the car's horn beeped. Then when I went outside I noticed that the charging port lights weren't blinking (they normally blink to indicate it's charging).

 

[dtbaker61]

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

my point is I cannot believe that document is correct.... It looks like maybe it was slapped together for Builders adding 'responder accessories', and not intended to apply to regular trims. This document is highly suspect in my eyes, it would make no sense at all not to maintain/charge the LVB when MME is on and driving. lights and sirens need to work whether the vehicle is moving or not.

The way I have observed my MME working is:

As soon as you turn the MME 'on', the dc-dc wakes up and brings the entire 12v system up to 13.5-14.5 volts.... supplying runtime power to all 12v accessories whether you are in Park, or Driving. Also charging the LVB as it is all in the same circuit and there is no 'disconnect' that takes the LVB out of the loop when you are not in Park.

When the MME is 'off', the LVB is powering the computers and there is some *small* drain on the LVB. If the computer/monitors/sensors/modules are working correctly, part of the processing they are doing even when the car is sleeping, is to check the LVB voltage occasionally. If and when the LVB drops to 11.9 from this background load, the MME is supposed to wake up the dc-dc and initiate a 'charge cycle' from the HV to maintain the LVB. It seems to bring the LVB up to about 12.8v and then go back to sleep.

That is the behavior when everything is working correctly as far as I know.

Problems occur if any of the sensors/modules are not working correctly, or if the LVB itself was damaged from deep discharge by not being maintained correctly when the MME was in 'transport mode'. Steps I would suggest for anybody suspecting their LVB system is not working correctly:

- (optional for the DIYer types) pull off the rear and drivers side beauty covers, disconnect the 12v ground for 10 minutes.... this should 'reset' all amp-hr counters, etc. reconnect, and consider adding 2" access holes for easy access in future if external 'jump' is needed or you want to measure system voltages directly.

- buy a $10 'socket' voltmeter, and stick it in one of the 'power ports' like the one in the armrest between driver and passenger. when the car is off, the accessory port voltage will hover between 12.1-12.4. in 'deep sleep', the power to the ports is cut and you will see no voltage at the accessory port, this is normal. If you leave the center cubby cover up and peek thru the window occasionally, you MAY see the accessory power come back on when it drops to 11.9-12.1 and wakes up the dc-dc for a sip of juice from the HV battery. When you enter the MME, and hit the 'on' button WITHOUT foot on the brake, the accessory port should wake up and show no less than 11.9 volts powered from the LVB. If you turn car 'on' the dc-dc kicks in and you should see 13.5-14.9v.

The only parameter I know of that prevents the 'wake and maintain' charge of the LVB is if the HV state of charge is very low.... the computer lets the LVB die rather than discharge the HV too much. Probably because the LVB can be revived with a jump, and its way more cost effective to replace the LVB than the HV. This is how *some* of the MMEs sitting around for too long at partial charge during delivery probably killed their LVB.... Or the parameters/modules to wake up the dc-dc were faulty.

....if the power port ever shows less than 11.9, then head for the Dealership because LVB is not getting charged and it will strand you.

 

[sockmeister]

This happen to me this morning. The two red battery indicators were illuminated when I tried to boot up the car.

What red battery indicators? If it's this icon:

That's normal, and appears every time the car is turned on briefly as a test.
If the icon remains on after more than a few seconds, or stays on permanently, then THAT's a problem.

But otherwise this is very normal, and it's on all the time while the car is in Accessory mode (on but not running).

 

[sockmeister]

It seems HV to LV charge is only during parking. They may not want the DCDC converter regularly working or regular external demands on HVB while driving. They probably didn't foresee the LVB being deconditioned during shipment delays and draining and dying during driving when it is not getting charged. This doesn't happen in ICE because of alternator. They need to enable LVB charging while driving when SOC is below a certain level.

Again, I don't think that's true.
Otherwise, the 12v battery would quickly die just from running the stereo system for 15 minutes, let alone they myriad of pumps and other equipment to maintain the 12v battery.

If you measure the voltage, it's at 14V while the car is running. The DC-DC converter runs all the time while the car is running.

 

[louibluey]

It seems HV to LV charge is only during parking. They may not want the DCDC converter regularly working or regular external demands on HVB while driving. They probably didn't foresee the LVB being deconditioned during shipment delays and draining and dying during driving when it is not getting charged. This doesn't happen in ICE because of alternator. They need to enable LVB charging while driving when SOC is below a certain level.

The LVB can be, and in my recent experience, the LVB is charged during driving. Here is an example:
Two short trips today ... DC/DC converter running while driving

Need to work this morning, but will study the Ford document and thread more later.

Clearly there are some serious LVB issues beyond the bogus 12V warnings. It will be interesting to see if there are any common elements, or two or more different root causes. For example, @Shayne I think found a note about an open hv contactor. I haven't studied the hv diagrams, but imagine that all hv is out in that case, including the DC/DC converter.

So, take the example by @Astraea, where the car was started several times during the day to be sure the LVB would be ready to go when needed, but then MME was dead. It could be (wild speculation) that the normal 40% to 90% off cycle was not working, and the several starts made the situation worse, not better, by using what was left of the LVB charge, reducing it each time.

Again, I have not studied the hv wiring, but it would seem that, in that condition, driving MME would be better, and if MME will move, then we know the hv contactor did close.

 

[louibluey]

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!

I think there may be some advantages to a slightly larger LVB, such as the RP rating, which supposedly refers to robustness during periods of non-use and more Ah, however a larger Ah battery will not solve the current crop of LVB problems.

The issue seems to be that LVB is not being properly maintained (not even to the 40% level) while off and parked. The additional question of plugged in or not can be considered, but at least parked, in this case MME still ended up dead, probably caused by a depleted 12V LVB.

Ironically, starting it several times, with failed charging while parked, probably made it worse, using the last of what charge was remaining at the end of the last drive (speculation).

So, a 35 Ah battery that is not being properly charged/maintained by MME (say by some kind of MME failure) vs. a 50 Ah battery not being charged, particularly on a -20F to 0F day is about the same, and both will fail, probably ending in the same dead MME. From the temps, I'm guessing you are north of here (I'm in the Utica area), maybe in the Plattsburgh area?

More later.

 

[Accord07]

As others have noted, I also see the voltage jump to ~14.1V immediately after starting my MME. I have also seen the reported LVB state of charge slowly increasing while the car was driven.

 

[DevSecOps]

For anyone who is interested I spent hours upon hours testing the voltages to the LVB for a different issue. In that case it was monitoring dips below 12.5 and cutting power to a dashcam. So, I had to figure out why the cutoff was happening and how to prevent it. More can be found here:

https://www.macheforum.com/site/threads/has-anyone-installed-a-power-magic-battery.11823/post-291728

 

[dtbaker61]

For anyone who is interested I spent hours upon hours testing the voltages to the LVB for a different issue. In that case it was monitoring dips below 12.5 and cutting power to a dashcam. So, I had to figure out why the cutoff was happening and how to prevent it. More can be found here:

https://www.macheforum.com/site/threads/has-anyone-installed-a-power-magic-battery.11823/post-291728

right, and so in the MME, did you ever see the LVB dip below 11.9 when it was 'off'?

and, can you confirm that as soon as the MME is on, system voltage comes up, and LVB is charging the whole time the vehicle is 'on'

 

[DevSecOps]

right, and so in the MME, did you ever see the LVB dip below 11.9 when it was 'off'?

and, can you confirm that as soon as the MME is on, system voltage comes up, and LVB is charging the whole time the vehicle is 'on'

My testing was specifically when the vehicle was off and when it was charging. So I didn't do any tests when it was on. I can and will do some for the purpose of helping ya'll here.

As for dropping below 11.9 when it was off, I never saw that. The lowest I saw it go was 12.3 when it was off and that was when the walk away lights were on etc. It would then bounce up once those lights were off and the car went to sleep.

While charging however it appeared that the battery was always being juiced, held and maintained 13.5.

I'll do some testing while on and let you know what I find.

 

[mikeho]

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!

Sent more details via PM

 

[dtbaker61]

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?

I don't think the battery is different.

The detail I noticed was the reference to a 220a dc-dc converter as opposed to the 160a on other trims. I do not know if this is true. Only thing I can think of is that the GT trim would be specified for higher pursuit speed, and the possible extra dc load for the Magnaride active suspension.

 

[littlD]

The same dead dinosaurs that charge my MME at 12am every day ?

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Granted, those electrons just contribute to the overall grid... yet

https://www.ameren.com/missouri/company/environment-and-sustainability/solar/community-solar

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