Joules
Member
- Joined
- Jan 20, 2022
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- 17
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- Location
- Utah
- Vehicles
- Mach e premium awd sr
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- Teacher
I appreciate your perspective. Thank you. I think you can see the part in question at thread below.This pending recall certainly raises a lot of questions/concerns. While we have not experienced any HVBJBL vehicle failures, we took vehicle delivery on 1/9/2022, I did notice some anomalies with the EVSE charging equipment over time. On a previous post I suggested to all to frequently check temperatures of the ESVE AC equipment/components during charging sessions. I check temps just about every week.
My garage /EVSE is the Ford OEM version, made by Webasto, with a 4 ft Pigtail, NEMA 1450, plugged into a NEMA 1450 receptacle on a 50 Amp circuit breaker circuit. I noticed from day one, that during a charge session @ 40 amp draw, there was a slight temp rise in the 1450 molded plug, pigtail and power cord that plugs into the car. Based on my electrical systems repair experience, I deemed a slight temp rise as normal. However, over time the 1450 power cord plug continued to register higher and higher temps. It went from a 10 degree rise, in a 70 degree ambient, in January to over a 70 degree rise in May, to approximately 150 degrees. This suggested a bad connection somewhere in the wall receptacle or inside the molded plug. I checked the wall plug connections, found nothing so then I replaced the molded plug and the problem went away. Therefore: There must have been a compromised wire connection inside the molded plug. ( Which was made in China . . . . . not surprised.)
Conclusion/concerns: IT appears I avoided an eventual electrical disaster by changing out the 1450 plug. I am 100% convinced that if I had not replaced the bad molded 1450 plug, it would eventually had a major thermal failure. But now I am left wondering about the high voltage circuitry inside the vehicle, where I cannot monitor component temps. It is obvious there is a problem with the HVBJB and it is heat related but what we do not know root cause: What type of connections does this device have? What is the source of the overheating problem? Is it mechanical connection assembly error or a design error or both? Is this a component design error? Not sure, but my own extensive electrical systems repair experience has taught me the problem could be one or the other or both.
I would be curious to see a HVBJB and electrical circuit schematic. From what I have read it sounds like an electromechanical device, like a typical electrical contactor relay. i.e. I read that the "contactors may melt/fuse". This is a typical electrical contactor type failure. However, with most , high voltage equipment, systems controlled by a contactor, they are usually easily accessible for eventual replacement and it is a 100% certainty, in typical high voltage/high amp load systems, the relay contactors will fail at some point. Therefore, did Ford engineers, in there great wisdom, foolishly bury this device in a place on the vehicle that is labor intensive to replace/repair? I guess we will find out.
As I speculate the root cause and possible solutions these thoughts occur to me: When in charging mode and/or driving mode does all high voltage battery power flow through the HVBJB? If it does than this device should have a design criteria to handle an extremely wide amperage load, i.e. up to 50 amps or more during L2 charging, much higher during DC Super charging sessions, and probably much higher during extreme vehicle acceleration. Therefore, if the design is minimal, it is going to constantly heat up and cool ( thermal cycling) under normal use. And this means, based on my electrical systems repair experience, the HVBJB connections/conditions should be routinely inspected/serviced. At this point, I am not aware of any such service recommendations for this vehicle.
Also, based on what I have read, this problem is not inherent in all MME's, but the problem does seem to occur with enough frequency to cause alarm. This suggests a possible assembly or use driven root cause, but in any case, it must be resolved.
As the Ford engineering team muddles through this problem, there will probably be several resolution options considered. If indeed all power flows through the HVBJB, and it is failing because of overheating the logical solution is to reduce amp/circuit load and therefore reduce the heat. However, that creates a host of compromising issues:
Admittedly, all of this is just my speculations, based on what I have experienced and what I have read. Time will tell what the final solutions will be. However, this unfortunate episode for the MME just reinforces my future plans to NOT own this vehicle past the warranty period. There will surely be continued EV design and technology improvements over the next couple of years and I do not want to be stuck with legacy technology issues.
- You can lower the charging rate, via software, but now it will take longer to charge the batteries and that will negatively impact the user experience/expectations.
- You can lower amperage loads during acceleration, to control HVBJB temp, but that will reduce vehicle performance, i.e. more user experience disappointments and a PR disaster because everyone in the EV market spaces brags about acceleration. .
- You can design, install a new improved HVBJB, that can handle a wider operational amperage, heat range and add temp sensors, along with analytical software to warn/predict failures. This means the recall includes a major parts replacement which will be time consuming , expensive and it will take time to develop/test.
- You can address possible assembly/manufacturing errors at the plant or vendors. This normally creates a manufacturing versus engineering "witch hunt" as the Ford organization tries to place internal or external blame for the problem. This will just slow down the eventual solution.
- Ford could locate this device in an easily accessible place for routine service. This will probably be very difficult/expensive on legacy vehicles and would be a redesign on new production.
What I am going to do, now, just in case..
Question: Does anyone have any detail information and/or photos the the HVBJBL? I would live to see how it is designed, hooked up, integrated into the system.
- Limit charging rates to 40 amps or less. I am considering resetting my EVSE to 35 amps.
- Avoid DC fast chargers. Those things push a lot of power, fast, back into the car and that creates heat.
- Closely watch this Forum for updates. Participants on this Forum all tell their "truth". They are not hindered by any corporate responsibilities/concerns/liabilities.
- Avoid jamming the accelerator, putting excessive load on the HVBJBL.
PS: To all my Forum colleagues that think by concerns are overblown. My lifelong professional experience as a Global Product Manager for a multinational, multi-billion dollar company taught me that sh*t happens. People, organizations, make mistakes.
Consider these questionable design/quality issues with the MME:
- You can't tow/pull this car from the rear. No pull points - major design mistake.
- There was an early recall because they did not glue the windshields or the roof glass properly. This was a major assembly/manufacturing error.
- There was a major problem with charging the Low voltage, 12v battery, that left a lot of users stranded. This was either a component or system design error.
- Now there is an elusive, yet to be resolved serious problem with the HVBJBL. This problem will eventually be resolved, but it will take time.
Good Luck to all.
https://www.macheforum.com/site/threads/my-stop-safely-now-saga.17610/
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