Survey: High Voltage Battery Junction Box issues?

[SpaceEVDriver]

If those of you who responded early to the survey would like to send me a DM with your responses to the survey and add responses to the three new questions, I can update the spreadsheet. I don't have your email address or any identifying information for you, so sending me just the responses for the new questions won't help correlate mileage and build date with your other data.

I won't be able to update the table until I'm back from field work in a couple of weeks. (Really, really wish I had my F-150 Lightning or R1T for field work.)

The three new questions are:

If you had a failure, what is the approximate mileage at the time of failure. If your vehicle has not experienced the failure, please enter 0.	What is your vehicle's current mileage?	What is your vehicle's build date?

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[dtbaker61]

Yes Sir Twice.
Towed in 01/04/22
Drove it it 02/14/22

I have several posts on this

I'm wondering if the shop was SURE they updated BECM, and put your 12v on a charger overnight before firing up the new HVBJB and test driving? i.e. if 12v was really weak and not charged, it would fit with the theory that low 12v causes HV contactors to flutter, arc, and fail.

 

[SpaceEVDriver]

great survey.... going to get some good data there I think.

In the meantime, I have a new theory on root cause of contactor (HVBJB) failure.... I'm thinking is could start with low 12v system voltage causing contactor relays to 'flutter' and not close solidly, arc, and weld shut.

I'm thinking that if the 12v battery happens to be run down, lets say close to 12.0 v, you hop in the car, start, turn on 12v loads like heat/air conditioning, then drive off right away... flipping on the 12v loads pulls the 12v system voltage down before the dc-dc has time time to 'charge the 12v', and the contactor relay can't hold good contact while you are accellerating getting rolling, and weld themselves together; which the car notices probably at your next stop when the contactors fail to open. This might also happen at a DCFC station I suppose if the 12v system is low, you plug in the DCFC and have big current flowing and the 12v system voltage sags a bit and can't hold the contactors....

This may explain why the vehicles don't have, or solve 12v charging issues, avoid the HVBJB problem.

Sounds like a possibility.

 

[Billyk24]

I'm wondering if the shop was SURE they updated BECM, and put your 12v on a charger overnight before firing up the new HVBJB and test driving? i.e. if 12v was really weak and not charged, it would fit with the theory that low 12v causes HV contactors to flutter, arc, and fail.

With the F150 EV in production. Will similar issues arrive in that vehicle?

 

[BigMach-E]

This is a highly unscientific response I am about to make, but I would say that incidence likelihood is close to 0.3 to 0.7 percent. This is extrapolated by knowing that at least 100 of the MMEs in the US have had this issue.

 

[Logal727]

This is a highly unscientific response I am about to make, but I would say that incidence likelihood is close to 0.3 to 0.7 percent. This is extrapolated by knowing that at least 100 of the MMEs in the US have had this issue.

Inside info?

 

[BigMach-E]

Inside info?

Not really, I have just seen the amount of people who have actually self-reported in this forum, and figured that conservatively, one could actually expect that it was about less than half of the actual occurrence. It's an significant number, but I hope it's not troubling to people about to take delivery. It happened to me, but I would still absolutely recommend the car. It's been about 4k miles since BECM and HVJBC replacement, hasn't happened again.

 

[SpaceEVDriver]

This is a highly unscientific response I am about to make, but I would say that incidence likelihood is close to 0.3 to 0.7 percent. This is extrapolated by knowing that at least 100 of the MMEs in the US have had this issue.

I've been throwing around 0.2 to 0.4% for basically the same reason you expounded on in your other post. There aren't 100 posts about it on this forum, but there are ways to extrapolate from a sample to the population. Simple ways and more complex ways, but the biggest difference is the confidence in the final extrapolation.

Given the lack of media about this, I suspect it's on the low end of 0.3-0.7%. If there were 420 worldwide, I think we would have heard something and it would have been picked up by all the anti-EV pundits out there. I mean we see posts on this forum picked up by various EV pundits at least a few times a month, so it's not like this is an obscure forum.

 

[BigMach-E]

I've been throwing around 0.2 to 0.4% for basically the same reason you expounded on in your other post. There aren't 100 posts about it on this forum, but there are ways to extrapolate from a sample to the population. Simple ways and more complex ways, but the biggest difference is the confidence in the final extrapolation.

Given the lack of media about this, I suspect it's on the low end of 0.3-0.7%. If there were 420 worldwide, I think we would have heard something and it would have been picked up by all the anti-EV pundits out there. I mean we see posts on this forum picked up by various EV pundits at least a few times a month, so it's not like this is an obscure forum.

Right, but I think we can definitely agree that this isn't happening to 12.5 percent of the vehicles out there. That would be a catastrophe, and would necessitate a full on recall. That's not what we have on our hands.

 

[SpaceEVDriver]

Right, but I think we can definitely agree that this isn't happening to 12.5 percent of the vehicles out there. That would be a catastrophe, and would necessitate a full on recall. That's not what we have on our hands.

Oh, yes, I absolutely agree.
It's not happening to even 1% of the cars that have been delivered. We would have heard by now if there were 600 cars with these failures.

The least interesting number in the survey is the Yes:No ratio.

Far more interesting is that there isn't (yet) a clear trim or drive or battery that stands out as obviously the main parameter in why the failure happens.

 

[BigMach-E]

Oh, yes, I absolutely agree.
It's not happening to even 1% of the cars that have been delivered. We would have heard by now if there were 600 cars with these failures.

The least interesting number in the survey is the Yes:No ratio.

Far more interesting is that there isn't (yet) a clear trim or drive or battery that stands out as obviously the main parameter in why the failure happens.

Yes, I don't think that such a parameter exists. Furthermore, I would go so far as to say I don't think there is a common parameter of user action beyond driving the car and charging the car. That being said, I have been far more mindful after having the parts replaced to press the charger unlock button, and the J1772 release trigger for 3 seconds prior to disconnect during a home charge session. Now I am thinking to be mindful to avoid having HVAC or lights or stereo running at first on the car, and waiting 30 seconds after turning it on to start moving.

 

[SpaceEVDriver]

Yes, I don't think that such a parameter exists. Furthermore, I would go so far as to say I don't think there is a common parameter of user action beyond driving the car and charging the car. That being said, I have been far more mindful after having the parts replaced to press the charger unlock button, and the J1772 release trigger for 3 seconds prior to disconnect during a home charge session. Now I am thinking to be mindful to avoid having HVAC or lights or stereo running at first on the car, and waiting 30 seconds after turning it on to start moving.

Yeah.

We're not going to develop a fishbone diagram that can solve this the problem; we just don't have the data.

But I do think we can have conversations that aren't based on fear or anger and try to understand if there are any approaches, like the ones you mentioned, that might provide some level of mitigation.

I still have no worries. It's like being a blade of grass on a golf course. We know some blades are going to be hit after a long drive, but most blades aren't going to be disturbed.

Of course, it would be nice to know this particular golfer's disc selection, disc speed, glide, turn, and fade so we know if we're in the path.

 

[BadgerGreg]

If those of you who responded early to the survey would like to send me a DM with your responses to the survey and add responses to the three new questions, I can update the spreadsheet. I don't have your email address or any identifying information for you, so sending me just the responses for the new questions won't help correlate mileage and build date with your other data.

I won't be able to update the table until I'm back from field work in a couple of weeks. (Really, really wish I had my F-150 Lightning or R1T for field work.)

The three new questions are:

If you had a failure, what is the approximate mileage at the time of failure. If your vehicle has not experienced the failure, please enter 0.	What is your vehicle's current mileage?	What is your vehicle's build date?

First time: ~19,000 miles
Second time: ~22,000 miles
My vehicle's build date is mid March 2021 (Job 1)

 

[Shayne]

First time: ~19,000 miles
Second time: ~22,000 miles
My vehicle's build date is mid March 2021 (Job 1)

Can you pipe in if you did not make the poll?
3 times ~600 km and last at ~9000 Km
Production Date: "2020-11-26",
received February 2, 2021
Hoping 3rd time is the charm?

 

[SpaceEVDriver]

Can you pipe in if you did not make the poll?
3 times ~600 km and last at ~9000 Km
Production Date: "2020-11-26",
received February 2, 2021
Hoping 3rd time is the charm?

Please fill out the survey in the first post. It's fully anonymous.

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