Is there a correlation between fast charging and HVB issues?

[MachLee]

Hi!
I am not the MachLee of which you seek. You're looking for @Mach-Lee.
Yes, I get that a lot lol.

Happy Driving!

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[Terence Murphy]

Drive up the Grapevine at 100 mph, and if your HVBJB is going to fail, I bet that puts at least one foot in its grave.

Care to guess at a mi/kWh draw estimate for this, or kW being pulled? Just curious how that compares to charging speed.

 

[mkhuffman]

Care to guess at a mi/kWh draw estimate for this, or kW being pulled? Just curious how that compares to charging speed.

It is a much higher load than doing a DCFC. When charging, at the max charge rate of 150 kW, the car will pull about 350 Amps. If you check out the data, some failures occurred when the car was pulling over 700 Amps. And all of the failures occurred at 400+ Amps.

Driving at high speed up the Grapevine is probably going to run 700+ Amps when accelerating, I bet. But only those who actually drove it know for sure...

Here is the link to the data if you have not seen it.
https://www.macheforum.com/site/threads/data-hvbjb-mega-data-aggregation-thread.21198/

 

[GordonW]

Interesting...sounds like the jury is still out about fast charging damaging battery. I used cruise control 95% of the time because I wanted to take advantage of the regeneration. Before the trip I was amazed at how many miles I would gain from it. I took the car up close to 120mph one time on the trip, but the rest of the time it was pretty much cruise control at 65-70mph. Fast charged to 100% a couple times on long legs of the trip, though after 80% the KWs would drop way off so I didn't think I was hurting the battery. When I get an answer from the dealer after the 10k check I will post what they say. Thank you all for your responses.

 

[mkhuffman]

Interesting...sounds like the jury is still out about fast charging damaging battery. I used cruise control 95% of the time because I wanted to take advantage of the regeneration. Before the trip I was amazed at how many miles I would gain from it. I took the car up close to 120mph one time on the trip, but the rest of the time it was pretty much cruise control at 65-70mph. Fast charged to 100% a couple times on long legs of the trip, though after 80% the KWs would drop way off so I didn't think I was hurting the battery. When I get an answer from the dealer after the 10k check I will post what they say. Thank you all for your responses.

The jury isn't out for me. DCFC does wear the battery more than L2 charging - that is a fact. But does it damage the HVBJB? I don't think it does, and so far, there is no data that indicates that it does. High speed driving, on the other hand...

 

[Peugfan]

It is a much higher load than doing a DCFC. When charging, at the max charge rate of 150 kW, the car will pull about 350 Amps. If you check out the data, some failures occurred when the car was pulling over 700 Amps. And all of the failures occurred at 400+ Amps.

Here is the link to the data if you have not seen it.
https://www.macheforum.com/site/threads/data-hvbjb-mega-data-aggregation-thread.21198/

Watching a teardown video of the HVJB, I seem to remember that the contactors used in DC fast charging were a different pair than those in driving. If that is true, then would not the specific contactors that failed give some clue to the problem. Can anyone clarify or correct my info.

 

[mkhuffman]

Watching a teardown video of the HVJB, I seem to remember that the contactors used in DC fast charging were a different pair than those in driving. If that is true, then would not the specific contactors that failed give some clue to the problem. Can anyone clarify or correct my info.

I believe it is the same set of contactors used for DCFC and driving, and there is a different set for L2 charging and maintaining the LVB. Maybe someone else can confirm my memory...

 

[Mach-Lee]

Watching a teardown video of the HVJB, I seem to remember that the contactors used in DC fast charging were a different pair than those in driving. If that is true, then would not the specific contactors that failed give some clue to the problem. Can anyone clarify or correct my info.

I can answer this since I've taken them apart. DCFC uses all 4 big contactors, so the current also flows through the main contactors.

Source: https://www.macheforum.com/site/thr...-the-problem-of-overheating-contactors.20373/

If you have a bad main contactor, high-power DCFC WILL heat it up. If it's already hot from driving this can further melt it and cause a SSN/stuck contactor after DCFC (or the next time the vehicle is shut off). Less than 100 kW charging isn't as much of a concern.

The HVBJB is going to fail regardless of if you DCFC or not. It's just a matter of time and how good of a part you got.

 

[Peugfan]

OK, now I can see that both DC fast charge and high power draw scenerios could be factors. Seems to me that high amps conversion to heat can happen quickly so that does not give much of a safety factor if part design is marginal.

 

[MellowJohnny]

<snip>
The HVBJB is going to fail regardless of if you DCFC or not. It's just a matter of time and how good of a part you got.

You figure even the "new" ones? I ask because half of me feels like essentially the HVBJB is a "wear" item, just like a clutch. Thoughts?

 

[Mach-Lee]

You figure even the "new" ones? I ask because half of me feels like essentially the HVBJB is a "wear" item, just like a clutch. Thoughts?

I think the new ones will be fine since they have the new contactor design, they will hopefully last the life of the pack. We haven't had any issues with them yet.

 

[GordonW]

You have no battery issues.

Your lost range was not lost. It was the vehicle's Guess-O-Meter reacting to your driving and conditions. You got lower miles per kilowatt than the factory default, and it adjusted to your driving, exactly as it is supposed to.

The displayed range is based on your driving history, and temps. The temps in Washington have dropped some, and therefore the range is lower than the day you got it when you had no driving history and it was warmer.

Ford knows everything you do with the car, so there is no creepiness about it. If you didn't understand this from day 1, now you do.

I expected Ford to know everything I do with the car, and I approved sending the extra data. What I didn't expect was their speaking to me in particular through a firmware update because I assume those updates go to all the cars. Also, the loss of range happened before the temps started to drop, we had our summer last through October this year. I've lost 33% of my battery's capacity, I think that is something the dealer or Ford needs to address, but we'll see. Thank you for your info.

 

[Mach-Lee]

I expected Ford to know everything I do with the car, and I approved sending the extra data. What I didn't expect was their speaking to me in particular through a firmware update because I assume those updates go to all the cars. Also, the loss of range happened before the temps started to drop, we had our summer last through October this year. I've lost 33% of my battery's capacity, I think that is something the dealer or Ford needs to address, but we'll see. Thank you for your info.

You went from temps in the 70's to temps in the 30's. That will cause a 33% range drop, which is normal for cold temps. You work in propane so I'll make an analogy. Just like the vaporization rate and pressure of propane drops in cold temps, the energy release rate of a battery also drops in cold temps due to slower chemical reactions. That effectively shrinks the capacity of the pack, just like the usable capacity of a propane tank shrinks in very cold weather (can't vaporize that last bit in the tank very fast). It's like trying to draw 200k BTU/hr continuously from a 250 gallon tank, that's fine in the summer but in the winter you might only be able to draw it down to 50% before it can't keep up anymore. The air is also more dense and you need to use cabin heat, both of which use more energy than driving in 70F weather. The range display factors that in, which is why it goes down in the winter. Expect to lose 40% of your range in the winter, it will come back next summer when it warms up. There is nothing for the dealer to address, that's just how it works due to the laws of nature.

 

[GordonW]

You went from temps in the 70's to temps in the 30's. That will cause a 33% range drop, which is normal for cold temps. You work in propane so I'll make an analogy. Just like the vaporization rate and pressure of propane drops in cold temps, the energy release rate of a battery also drops in cold temps due to slower chemical reactions. That effectively shrinks the capacity of the pack, just like the usable capacity of a propane tank shrinks in very cold weather (can't vaporize that last bit in the tank very fast). It's like trying to draw 200k BTU/hr continuously from a 250 gallon tank, that's fine in the summer but in the winter you might only be able to draw it down to 50% before it can't keep up anymore. The air is also more dense and you need to use cabin heat, both of which use more energy than driving in 70F weather. The range display factors that in, which is why it goes down in the winter. Expect to lose 40% of your range in the winter, it will come back next summer when it warms up. There is nothing for the dealer to address, that's just how it works due to the laws of nature.

Yes, I understand that, but it was in the 60's all the way through October this year in the northwest and I noticed the loss during that month, right after my trip. I suppose the dealer will say the same thing and I will have to wait until next spring to make my case. Its okay for now, I never drive over 100 miles in a day so I'll be fine until then. Thank you for your intelligent reply, its nice to find people that know what's going on "under the surface" with things like propane. Its amazing to me that propane vapor can be compressed 271 times its normal volume.

 

[Mach-Lee]

Yes, I understand that, but it was in the 60's all the way through October this year in the northwest and I noticed the loss during that month, right after my trip. I suppose the dealer will say the same thing and I will have to wait until next spring to make my case. Its okay for now, I never drive over 100 miles in a day so I'll be fine until then. Thank you for your intelligent reply, its nice to find people that know what's going on "under the surface" with things like propane. Its amazing to me that propane vapor can be compressed 271 times its normal volume.

Thanks, I try. So if the range loss happened with the same temps, then it's due to a driving style change. If you took a trip at faster speeds than you normally drive, it will average that in and the range will go down since 70+ MPH takes a lot more energy than 50+ MPH for everyday driving. I think it looks at average efficiency over last 500 miles as part of the range calculation. The latest version will also adjust your range based on your nav destination and expected average speed and terrain on the route.

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