Marlin's Dead Low Voltage Battery (LVB) -- Followed by Stuck in Park

[dtbaker61]

AGM batteries are not happy if they are charged too quickly - above 13.8V, if I remember correctly. With ICE alternators, charge voltage is typically 14.4, but if you install an AGM, the voltage needs to be turned down to below 13.8V. The company I work for builds a vehicle with AGM battery because it often sits without being used for weeks at a time. However, a special 13.8V alternator is used. Anyone know what the DC-DC LV charging voltage is?

AGM batteries have a slightly lower charge/equalize voltage because they are sealed and you don't want the electrolyte in the 'glass mat' to boil and create gas/pressure inside the battery or dry out the mat. The dc-dc output voltage is probably controlled pretty tightly and factory set for the AGM installed in the car, and compensates for voltage drop in the LVB with low temperatures. Tight control of the charge voltage is needed to regulate the current going INTO the battery to prevent problems and extend life.

This is why my best guess is there are some issues with the dc-dc voltage regulation, charge controller, software, and/or sensors monitoring the LVB voltage and temp. which *might* be temporarily sidestepped by swaddling your LVB in a 12v electric blanket for the winter... at least until there is a more general fix

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[ChasingCoral]

Friday evening update: Marlin won't be home this weekend.

I spent 20 minutes late this afternoon chatting with the Field Service Engineer who has been working with Marlin at Koons Ford all week. It looks like Marlin had a "common" (my word) problem followed by a unique problem.

First a correction. The FSE working on Marlin wasn't sent down from Dearborn as someone at Koons had told me. He's one of a couple of FSEs assigned to this area (makes much more sense).

The "common" problem:
I don't say this meaning it is common to all the early build Mach Es. However, it has been seen in multiple Mach Es (perhaps @eponyinIL and others here who have had drained LVBs) and is being solved with a software update. My understanding of the problem explains why it looks like there are two problems: a vampire loss from the LVB and the HVB isn't keeping the LVB charged. It is really just one problem: sometimes, after charging ends for whatever reason, a system related to the DC-DC converter is somehow remaining open and draining the LVB. That explains why the LVB is draining and the DC-DC converter isn't keeping it recharged off the HVB. The solution is a software upgrade with the latest version that should eliminate this situation. It sounds like the same solution applied to @eponyinIL's Mach E and is how they solved Marlin's battery drain issue.

The unique problem:
Unfortunately, when one of the Koons employees went to drive Marlin around from the shop for me to take him home, something activated the electronic parking brake pawl. This is not the drive problem other cars have had and has only been seen in a couple of EU preproduction models with very different control modules. The good news is there has been no sign the battery issue is still there and they managed to get the problem cleared today and test drove Marlin but they can't fully reproduce the issue or identify the problem, even with a bunch of sophisticated sensor equipment plugged into Marlin and the enhanced logging software. With a desire to give it more intense diagnostics to find and solve the second issue, the FSE asked my permission to move Marlin up to Ford's Washington, DC area Training Facility up in Frederick, MD. There, the FSE and regional service trainer, collaborating with the Dearborn team, can better work on Marlin to get to the bottom of the issue. They'll probably take him up there Monday.

I did volunteer to take Marlin over the weekend and do some driving so they can gather more data. I also offered to drive him up to Frederick. The FSE indicated such a decision was well over his head and suspects the answer will be no ?. It was worth asking, though .

The FSE was great to talk with, very apologetic this was happening but very reassuring that the Ford engineering team is doing everything they can to diagnose and solve the problem.

I definitely won't have Marlin back (for good) before next week. It looks like I may have to scratch the plan to get PPF and ceramic before heading to Florida. The Florida trip may still be possible. ?

I should get regular, perhaps daily, updates from them next week.

So, a slight update to my earlier post:
The unique problem, the “can’t shift out of park” appears to be a voltage anomaly that occurred on one of the circuits that communicates with the Integrated Park Module. That is what they will be addressing at the regional Service Training center in Fredrick, MD.

 

[MitchAK]

Part 2 of this saga is getting to the bottom of the problem. Here's where I think a very important message needs to be included: Ford is really standing behind the Mach E.

Note that Marlin shut down on Saturday night. The friends I mentioned in the first post reached out to some folks in Ford. The Mach E engineering team was communicating with me on Sunday. By Sunday night they were already running some diagnostics they could do on the telemetry the car sends out and had started reviewing the videos I posted above. I dropped off Marlin Sunday afternoon. By Monday morning Ford engineers had been talking with the management and shop foreman at Koons Ford to prepare diagnostics and work. That's where we stand now. I feel confident that they are all working to figure out this problem to get Marlin back in top shape and prepare to help others who have posted similar issues. More on this as I find out how it is going.

Sorry for your troubles, and thanks for documenting it and taking the time to lay it all out.
I hope all is well for you and hopefully if I get mine soon ill know what to do. ?

 

[ChasingCoral]

Sorry for your troubles, and thanks for documenting it and taking the time to lay it all out.
I hope all is well for you and hopefully if I get mine soon ill know what to do. ?

Hopefully when you get yours, you won't need to do anything!

 

[engnrng]

AGM batteries have a slightly lower charge/equalize voltage because they are sealed and you don't want the electrolyte in the 'glass mat' to boil and create gas/pressure inside the battery or dry out the mat. The dc-dc output voltage is probably controlled pretty tightly and factory set for the AGM installed in the car, and compensates for voltage drop in the LVB with low temperatures. Tight control of the charge voltage is needed to regulate the current going INTO the battery to prevent problems and extend life.

This is why my best guess is there are some issues with the dc-dc voltage regulation, charge controller, software, and/or sensors monitoring the LVB voltage and temp. which *might* be temporarily sidestepped by swaddling your LVB in a 12v electric blanket for the winter... at least until there is a more general fix

Great information, Dan, thanks! I saw a photo of 12V socket voltage well over 15V, but that may not have been reading the voltage being supplied to the battery itself, which is probably regulated separately after the DC-DC bus.

 

[MitchAK]

Hopefully when you get yours, you won't need to do anything!

Amen ?

 

[BK2EV]

Thanks Coral for all you have endured and helped with the issue(s). You are a patient person for sure.

Hopefully when things are figured out we will all be good with zero worries.

When you get your car back the mexican (and beer) is on me.

Thanks

BK2EV

 

[back_at_it_19]

BEVs, 30% coal fired.

0% coal here. 100% hydro, wind, nuclear.

 

[Griddlez]

Wanted to be another saying thanks for keeping us all updated and hope you have your car back real soon. Ford seems to be sparing no effort, great to see.

P.S. Where did you get all your sweet ME apparel? I kinda want some now haha.

 

[Maric]

I wrote a letter to Biden asking for the congressional Medal of Honor for @ChasingCoral . You deserve it!

In all seriousness as other have pointed out, you are handling this better than most anyone else would. I hope Ford compensates you somehow. Again, you deserve it! Hope you have Marlin back soon!

 

[Accord07]

I wrote a letter to Biden asking for the congressional Medal of Honor for @ChasingCoral . You deserve it!

In all seriousness as other have pointed out, you are handling this better than most anyone else would. I hope Ford compensates you somehow. Again, you deserve it! Hope you have Marlin back soon!

Uh, I think you either meant the Presidential Medal of Freedom, or should have written to Pelosi instead ? Either way, I agree that @ChasingCoral deserves the medal.

 

[ChasingCoral]

BEVs, 30% coal fired.

Not mine. When I charge at home (>90% of my charging) I get ~70% solar, 30% regional wind.

 

[ChasingCoral]

Wanted to be another saying thanks for keeping us all updated and hope you have your car back real soon. Ford seems to be sparing no effort, great to see.

P.S. Where did you get all your sweet ME apparel? I kinda want some now haha.

Thanks.

Mach E gear is from our own @Mach-E VLOG and @Liv's Redbubble store:
https://www.redbubble.com/people/zealology/shop

 

[mattsaradan]

Not mine. When I charge at home (>90% of my charging) I get ~70% solar, 30% regional wind.

100% wind RECS here

 

[SnBGC]

AGM batteries are not happy if they are charged too quickly - above 13.8V, if I remember correctly. With ICE alternators, charge voltage is typically 14.4, but if you install an AGM, the voltage needs to be turned down to below 13.8V. The company I work for builds a vehicle with AGM battery because it often sits without being used for weeks at a time. However, a special 13.8V alternator is used. Anyone know what the DC-DC LV charging voltage is?

According to the service manual it is variable.

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