Do you think it’s likely that the 5 second acceleration limit will change?

[BigMach-E]

It doesn’t bother me too much, and I totally understand that there are a lot of factors at play. However, the unnamed T company could and did unlock performance on some of their vehicles after purchase as a cynical money grab. I know some folks (like me in the past) tend to drive a car until it costs more to upkeep then to buy another. Do you think Ford might leave the money on the table for people who won’t buy another in the short term, but would be willing to part with 1-2k to have Ford unlock the limiter?

Do you think that either this community or some outside enterprise will come up with a “fix”? I personally am leaving my car bone stock while it is still under warranty, and possibly forever.

I know that the limiter is in place for battery longevity, braking performance, thermal management and to prevent HVJB welds, and so I wouldn’t ever consider aftermarket, but I feel some would. Thoughts?

There are a bunch of smart folks here who know how to code, know their in’s and outs of FORSCAN and FDRS. The limiter is likely software based, correct? Is there any real hardware component to it?

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[Mach-Lee]

The limit is in place so the battery doesn’t start on fire. A completely new pack design that supports more amps would be required before anything will change. Maybe the next version of the Mach-E will have an upgraded GT pack, but there is no hope for current GT models. Aftermarket won’t be able to fix this either since the problem is with the entire pack design.

 

[BigMach-E]

The limit is in place so the battery doesn’t start on fire. A completely new pack design that supports more amps would be required before anything will change. Maybe the next version of the Mach-E will have an upgraded GT pack, but there is no hope for current GT models. Aftermarket won’t be able to fix this either since the problem is with the entire pack design.

I’m not disagreeing with you on this, I want that to be clear.

I am just asking if you can point me in the direction to some data that validates that the battery has a high potential for thermal runaway due to complete pack design if there wasn’t a limiter in place.

Isn’t it possible that the limiter is in place due to the HVJB or another component? Does removing it require a full pack redesign?

 

[AKgrampy]

I’m not disagreeing with you on this, I want that to be clear.

I am just asking if you can point me in the direction to some data that validates that the battery has a high potential for thermal runaway due to complete pack design if there wasn’t a limiter in place.

Isn’t it possible that the limiter is in place due to the HVJB or another component? Does removing it require a full pack redesign?

I can’t point you anywhere but I too recall that it is the battery manufacturer that essentially necessitated the 5 sec limit. It may well be for thermal runaway as you mention but my guess is the buss-work is not rated for the continuous amps and it will become damaged. That includes the contacts in the HVBJB I believe. There is a thread somewhere where you can find the part number for the contacts and then review their specs.

 

[Mach1E]

I’m not disagreeing with you on this, I want that to be clear.

I am just asking if you can point me in the direction to some data that validates that the battery has a high potential for thermal runaway due to complete pack design if there wasn’t a limiter in place.

Isn’t it possible that the limiter is in place due to the HVJB or another component? Does removing it require a full pack redesign?

The “so it doesn’t start on fire” is hogwash/hyperbole.

We do have logged data from all the temp sensors in the car.

When you floor it, temps very temporarily spike, then actually drop even during the 5 seconds of full throttle.

Fire wouldn’t happen.

Battery temps? Almost unchanged during full throttle runs.

That said, there are plenty of components just not up to the task. The HVJB can’t even handle the power of a rwd sr let alone a GT.

So Ford isn’t going to change it until they beef up the components (future models).

Obviously they know how (Lightning).

Aftermarket tuners seem uninterested. Even Shelby has been silent for 2 years on power upgrades.

 

[Mach-Lee]

I am just asking if you can point me in the direction to some data that validates that the battery has a high potential for thermal runaway due to complete pack design if there wasn’t a limiter in place.

Isn’t it possible that the limiter is in place due to the HVJB or another component? Does removing it require a full pack redesign?

I've spent time examining the design of the pack, size of busbar, cell tabs, etc and it's my own engineering opinion. For example, the size of the busbar in the Model S plaid pack is about 6x larger than our busbars even though it only has 2x more horsepower. That would suggest our busbars are undersized by a factor of 2-3x.

See: https://www.macheforum.com/site/thr...ain-contactors-may-overheat.18681/post-442187

The “so it doesn’t start on fire” is hogwash/hyperbole.

We do have logged data from all the temp sensors in the car.

When you floor it, temps very temporarily spike, then actually drop even during the 5 seconds of full throttle.

Fire wouldn’t happen.

Battery temps? Almost unchanged during full throttle runs.

It's not hogwash, I've explained this before, but there aren't temp sensors in the hot spots in the pack! You cannot conclude the busbars are not getting hot just because you don't see a hot cell temp reading on the scan tool! The scan tool only shows you the internal cell temps which are nowhere close to to the tabs and busbars which are the things that get hot first. The cell temp sensors are LAST to warm up in the pack.

I can guarantee you running 1050 amps through a 1/8" x 3/4” busbar is going to get it HOT in a jiffy. That's about the size of #0 gauge wire, which is only rated for about 170 amps in an AC power application. In other words, they are running 6 times more current through the busbar than you legally could if it was installed in your house. Ford is already running the thing at the absolute limit with the 5 second rule in place.

This is still my argument: https://www.macheforum.com/site/thr...due-to-battery-manufacturer.17580/post-428879

 

[Mach-Lee]

Any for anyone that doesn't believe me, this is what 1000 amps (same current as GTPE) does to a kitchen knife and lawnmower blade:




Notice how it's glowing in less than 10 seconds. And the Mach-E busbar is smaller than that knife.

Shorting out a car battery is also going to be around 1000 amps:

 

[breeves002]

I've spent time examining the design of the pack, size of busbar, cell tabs, etc and it's my own engineering opinion. For example, the size of the busbar in the Model S plaid pack is about 6x larger than our busbars even though it only has 2x more horsepower. That would suggest our busbars are undersized by a factor of 2-3x.

See: https://www.macheforum.com/site/thr...ain-contactors-may-overheat.18681/post-442187



It's not hogwash, I've explained this before, but there aren't temp sensors in the hot spots in the pack! You cannot conclude the busbars are not getting hot just because you don't see a hot cell temp reading on the scan tool! The scan tool only shows you the internal cell temps which are nowhere close to to the tabs and busbars which are the things that get hot first. The cell temp sensors are LAST to warm up in the pack.

I can guarantee you running 1050 amps through a 1/8" x 3/4” busbar is going to get it HOT in a jiffy. That's about the size of #0 gauge wire, which is only rated for about 170 amps in an AC power application. In other words, they are running 6 times more current through the busbar than you legally could if it was installed in your house. Ford is already running the thing at the absolute limit with the 5 second rule in place.

This is still my argument: https://www.macheforum.com/site/thr...due-to-battery-manufacturer.17580/post-428879

This 100%. They don’t have temp sensors literally everywhere they have calculations to figure out temp limits of other components not monitored. Like the bus bars…

 

[Mach1E]

I've spent time examining the design of the pack, size of busbar, cell tabs, etc and it's my own engineering opinion. For example, the size of the busbar in the Model S plaid pack is about 6x larger than our busbars even though it only has 2x more horsepower. That would suggest our busbars are undersized by a factor of 2-3x.

See: https://www.macheforum.com/site/thr...ain-contactors-may-overheat.18681/post-442187



It's not hogwash, I've explained this before, but there aren't temp sensors in the hot spots in the pack! You cannot conclude the busbars are not getting hot just because you don't see a hot cell temp reading on the scan tool! The scan tool only shows you the internal cell temps which are nowhere close to to the tabs and busbars which are the things that get hot first. The cell temp sensors are LAST to warm up in the pack.

I can guarantee you running 1050 amps through a 1/8" x 3/4” busbar is going to get it HOT in a jiffy. That's about the size of #0 gauge wire, which is only rated for about 170 amps in an AC power application. In other words, they are running 6 times more current through the busbar than you legally could if it was installed in your house. Ford is already running the thing at the absolute limit with the 5 second rule in place.

This is still my argument: https://www.macheforum.com/site/thr...due-to-battery-manufacturer.17580/post-428879

Hot? Yes.

Catch fire? Hyperbole/hogwash.

This “your car will explode in a ball of flames” argument always seems to show up in the 5 second debate.

And yet? No Mach Es have caught fire due to heat from acceleration.

I don’t know that any BEV from any manufacturer has (from heat from acceleration).

Now if you run it into a tree and rupture your battery…… that’s a different story.

I do not believe that we are a few seconds away from catching fire, and that if we didn’t have the limit that we would.

FWIW, I do agree, like I said above, that the components are under engineered and can’t take the heat. Just not sure why people always claim “fire.”

 

[BigMach-E]

Any for anyone that doesn't believe me, this is what 1000 amps (same current as GTPE) does to a kitchen knife and lawnmower blade:




Notice how it's glowing in less than 10 seconds. And the Mach-E busbar is smaller than that knife.

Shorting out a car battery is also going to be around 1000 amps:

Thank you for educating us, I appreciate it. I can live with the design, it’s not a terrible disappointment. The MME GTPE is plenty quick enough for me as it is, big of course one could always want more.

 

[breeves002]

And yet? No Mach Es have caught fire due to heat from acceleration.

Yes because the limits are working as designed in software ???

 

[Mach1E]

Yes because the limits are working as designed in software ???

?

None turn into flying unicorns either. Does this prove the software prevents that as well?

Can’t use the lack of something as proof it exists.

I’ll add flying unicorns into the same hyperbole category as Mach Es catching fire. Feel free to come back and tell me I’m wrong if you run into either one of those things. ?

The software is designed to prevent component failure. But failure doesn’t mean fire (as we learned from the HVJB ).

 

[MachEMaster]

Bring on the 2026 MME!

 

[breeves002]

?

None turn into flying unicorns either. Does this prove the software prevents that as well?

Can’t use the lack of something as proof it exists.

I’ll add flying unicorns into the same hyperbole category as Mach Es catching fire. Feel free to come back and tell me I’m wrong if you run into either one of those things. ?

The software is designed to prevent component failure. But failure doesn’t mean fire (as we learned from the HVJB ).

I mean it won’t necessarily catch on fire, in fact it’s fairly unlikely, but it’s absolutely possible. It’s likely 10 seconds at 1050A would melt the insulation on the bus bars which would be problematic.

I really am not sure what you’re arguing. Fire is possible, just unlikely. The risk is not 0. If you don’t limit the power the bus bars are going to melt the insulation, warp, and over time have issues. If you had 1050A for 30+ seconds you may even melt them. Watch the video mach_lee posted again. That could start a fire,

 

[Mach1E]

I mean it won’t necessarily catch on fire, in fact it’s fairly unlikely, but it’s absolutely possible. It’s likely 10 seconds at 1050A would melt the insulation on the bus bars which would be problematic.

I really am not sure what you’re arguing. Fire is possible, just unlikely. The risk is not 0. If you don’t limit the power the bus bars are going to melt the insulation, warp, and over time have issues. If you had 1050A for 30+ seconds you may even melt them. Watch the video mach_lee posted again. That could start a fire,

Sure it’s theoretically possible. Any time there is high heat there “in theory” could be fire.

What am I arguing though?

That this statement in the beginning of this thread “The limit is in place so the battery doesn’t start on fire.”

Is hyperbole and just really not true.

That’s like saying we have radiators so we don’t catch fire. Fire is the super duper unlikely thing that would happen after a ton of other horrible things happen first.

The reason isn’t “fire prevention.” The reason is component failure.

The components would fail waaaaaaaay before any risk of fire.

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