Meet a Ford Engineer Today

[dbsb3233]

Yes I know, I'm either a) preaching to the choir here; or b) preaching to those who don't mind, but this is certainly the only part of the car that's annoying to me - even PaaK, which doesn't even work on any of my phones, is as annoying!

I guess I'm a lot closer to the (b). While it would certainly be nicer if that 80% cliff were at 90% instead, I don't really find it to be all that significant in practice. But I do see a number of reactions like yours that think it's a really big deal. I'm curious why?

For road trips, I usually leave home (or the hotel) at 100%, so I get max range out of the first leg. My understanding is that most people usually only charge other BEVs to around 70-80% on DCFC anyway because of tapers (they're just not as dramatic of a cliff as the MME). So the 2nd/3rd/4th legs are usually shorter in any BEV.

In studying some other BEV charge curves, the MME looks like it actually holds power up to 80% better than many. I'm usually still seeing 85kW all the way to 80%, which is quite good. Many BEVs are down to ~50kW by that point. So while we lose some after 80%, we gain some before 80%. And the part before 80% is far more important since we commonly actually charge there.

I just charge to 80% each DCFC leg. If it's the lunch stop, we might take an hour to eat in-restaurant and let it go past 80%, which is fine too (prevents idle charges).

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[silverelan]

interesting that he says 80% rather than the 90% in the manual says. I am wondering how much of a degradation they found between 80% and 90%. It must still be sizeable to recommend that over 90%.

I'd bet it's more

I guess I'm a lot closer to the (b). While it would certainly be nicer if that 80% cliff were at 90% instead, I don't really find it to be all that significant in practice. But I do see a number of reactions like yours that think it's a really big deal. I'm curious why?

For road trips, I usually leave home (or the hotel) at 100%, so I get max range out of the first leg. My understanding is that most people usually only charge other BEVs to around 70-80% on DCFC anyway because of tapers (they're just not as dramatic of a cliff as the MME). So the 2nd/3rd/4th legs are usually shorter in any BEV.

In studying some other BEV charge curves, the MME looks like it actually holds power up to 80% better than many. I'm usually still seeing 85kW all the way to 80%, which is quite good. Many BEVs are down to ~50kW by that point. So while we lose some after 80%, we gain some before 80%. And the part before 80% is far more important since we commonly actually charge there.

I just charge to 80% each DCFC leg. If it's the lunch stop, we might take an hour to eat in-restaurant and let it go past 80%, which is fine too (prevents idle charges).

Just like everybody else, I'm really curious why Ford went with a unique time-based system for DC fast charging instead of a more conventional approach.

Ford's time-based profile does have its advantages if you start your charge session from between 30-40% vs a conventional charge curve. A VW ID.4 has a charging curve that's already tailing off at 40%.

I think people are grumpy about the MME DC charging because we get a two minute glimpse of what it can do before it settles into an unremarkable ~100kW average over 30 minutes.

 

[dbsb3233]

I'd bet it's more


Just like everybody else, I'm really curious why Ford went with a unique time-based system for DC fast charging instead of a more conventional approach.

Ford's time-based profile does have its advantages if you start your charge session from between 30-40% vs a conventional charge curve. A VW ID.4 has a charging curve that's already tailing off at 40%.

I think people are grumpy about the MME DC charging because we get a two minute glimpse of what it can do before it settles into an unremarkable ~100kW average over 30 minutes.

Yeah I see some of that too (why only super power for 2 minutes?). And I get the frustration over that one more.

But I see a lot of very strong comments about the 80%. That's the one I'm more curious about why such strong feelings, since it rarely even comes into play for any BEV.

 

[db4z]

I'd bet it's more


Just like everybody else, I'm really curious why Ford went with a unique time-based system for DC fast charging instead of a more conventional approach.

Ford's time-based profile does have its advantages if you start your charge session from between 30-40% vs a conventional charge curve. A VW ID.4 has a charging curve that's already tailing off at 40%.

I think people are grumpy about the MME DC charging because we get a two minute glimpse of what it can do before it settles into an unremarkable ~100kW average over 30 minutes.

They could have gone time based because the hottest spot in hotest battery cell does not have a temperature sensor directly on that hot spot, and therefore a safe time limit was developed off of special development batteries covered in hundreds of temperature sensors.

Another way to look at it is they may have developed the battery pack for a lower charge limit (say 100kw) but then realized they could safely allow for a short burst of higher charging up to 150kw, helping with the total power/range added for those quick 10-15 mins stops.

 

[dbsb3233]

Another way to look at it is they may have developed the battery pack for a lower charge limit (say 100kw) but then realized they could safely allow for a short burst of higher charging up to 150kw, helping with the total power/range added for those quick 10-15 mins stops.

Perhaps, but it's pretty minuscule. Getting 160 kW for 2 minutes instead of probably 120 at that point is an extra 1.3 kWh. Saving less than a minute.

I suspect it's more just to say they met the "150 kW" charging claim.

 

[kltye]

I guess I'm a lot closer to the (b). While it would certainly be nicer if that 80% cliff were at 90% instead, I don't really find it to be all that significant in practice. But I do see a number of reactions like yours that think it's a really big deal. I'm curious why?

For road trips, I usually leave home (or the hotel) at 100%, so I get max range out of the first leg. My understanding is that most people usually only charge other BEVs to around 70-80% on DCFC anyway because of tapers (they're just not as dramatic of a cliff as the MME). So the 2nd/3rd/4th legs are usually shorter in any BEV.

In studying some other BEV charge curves, the MME looks like it actually holds power up to 80% better than many. I'm usually still seeing 85kW all the way to 80%, which is quite good. Many BEVs are down to ~50kW by that point. So while we lose some after 80%, we gain some before 80%. And the part before 80% is far more important since we commonly actually charge there.

I just charge to 80% each DCFC leg. If it's the lunch stop, we might take an hour to eat in-restaurant and let it go past 80%, which is fine too (prevents idle charges).

My use case is probably quite different than most. I don't have home (or reliable work) charging, and every so often I make a trip to from Chicago to West Virginia (aka no DCFC in the entire state), which is already a long trip to make in a gas car, and "wasting" almost an hour (compared to faster-charging EVs) to get to my destination with a reasonable amount of charge is frustrating.

Yes yes, I know I made the decision to buy an EV when I don't have at-home charging, etc. etc., but the point is it seems possible for the pack to charge much faster, yet we're stuck with this very odd charging curve. I get that Ford really wants to discourage DCFC especially at high SoC, but I still think we deserve to be treated like adults and make the decisions for ourselves by either a) allowing us to limit charge rates easily, or b) give us a stern warning every time we charge above 80% with DCFC.

 

[silverelan]

Another way to look at it is they may have developed the battery pack for a lower charge limit (say 100kw) but then realized they could safely allow for a short burst of higher charging up to 150kw, helping with the total power/range added for those quick 10-15 mins stops.

I'm wondering if the MME's origin as an uninspired compliance car has anything to do with its ho-hum charging and cooling? Chief Heiser had only two years or so to pivot from a me-too EV to a Mustang so he had to work with what was already there. 100kW charging for a 300mi FWD EV version of the Escape would have been generally accepted as pretty good.

 

[Pibbman]

At a car show I was at today in Utica, NY, a young guy walked up to me and presented a small Mach-E Pony Logo sticker and introduced himself as a Ford Engineer who works on the Mach-E team. After talking for a few minutes I found out he had his Mach-E out in the parking lot nearby.

He had an Iconic Silver Premium with Extended Battery which was the other color I was considering before my wife indicated she preferred IB.

In talking with him, he shared some graphs on the data they worked with on the Mach-E battery life. He showed me a chart indicating if an owner charged his Mach-E to 100% on L2 charging only, the battery would only degrade 5% over 5 years. Less degradation at 90% and 80%. He said Ford was assuming owners would only DC Fast Charge a couple of times a month on average over the length of ownership. The more DC Fast Charging the faster the battery pack will degrade. I believe that is common knowledge and applicable to all current EV battery tech.

do you happen to remember the percentage of degradation for 90% and 80% over 5 years?

 

[JohnnyForensic]

I'm wondering if the MME's origin as an uninspired compliance car has anything to do with its ho-hum charging and cooling? Chief Heiser had only two years or so to pivot from a me-too EV to a Mustang so he had to work with what was already there. 100kW charging for a 300mi FWD EV version of the Escape would have been generally accepted as pretty good.

Maybe it's safety involved? Enough EVs have caught fire when charging that maybe Ford said, "Let's try to avoid this, shall we?"

At least I hope that's what happened.

 

[ChasingCoral]

At a car show I was at today in Utica, NY, a young guy walked up to me and presented a small Mach-E Pony Logo sticker and introduced himself as a Ford Engineer who works on the Mach-E team. After talking for a few minutes I found out he had his Mach-E out in the parking lot nearby.

He had an Iconic Silver Premium with Extended Battery which was the other color I was considering before my wife indicated she preferred IB.

In talking with him, he shared some graphs on the data they worked with on the Mach-E battery life. He showed me a chart indicating if an owner charged his Mach-E to 100% on L2 charging only, the battery would only degrade 5% over 5 years. Less degradation at 90% and 80%. He said Ford was assuming owners would only DC Fast Charge a couple of times a month on average over the length of ownership. The more DC Fast Charging the faster the battery pack will degrade. I believe that is common knowledge and applicable to all current EV battery tech.

Good enough for me. I just backed my standard charging off to 80%. Thanks.

 

[Larry Paul]

Moral of the story, don’t DC fast charge unless necessary such as a long trip.

Does anyone have a copy of that chart? The link from the thread seems to be broken.

View attachment 33957

 

[stmache]

Does anyone have a copy of that chart? The link from the thread seems to be broken.

View attachment 33957

If you are referencing the chart I saw, I was not allowed to photograph it to share.

 

[Larry Paul]

If you are referencing the chart I saw, I was not allowed to photograph it to share.

Yes I was asking about that- there was a link to I presume that image- but the link is not live…

 

[stmache]

Yes I was asking about that- there was a link to I presume that image- but the link is not live…

The link was for a photo of the engineer's car which I removed for privacy reasons.

 

[Malacandra]

No but I could guess his answer by the way he talked about charging the batteries. I said couldn't I just charge it to 100% every night since there's a 11 Kwh buffer? He said he'd recommend 80% if you didn't need the range on a daily basis. As has been postulated a few times here, Ford is being VERY careful with the battery packs until they get a lot more data. So, I'd guess, he would have told me "no" on the question of improving the Fast Charging curve.

He also said, for those thinking Ford will lower that buffer, it will not happen. I believe he reads this forum, too. Hi!

I just found this thread.

It turned out the Ford is both decreasing that battery buffer and improving the fast charging curve. Which goes to show how hard it is to predict which way Ford will zig or zag.

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