5 Second Battery Limit due to Battery manufacturer?

[MachEMaster]

I believe the engineers' concern was heating in connections and areas that don't have temperature sensors. Just because you don't see crazy temps on scan data doesn't mean they aren't happening somewhere. Components only have a certain surge capacity. If the full current continued for too long it may have melted connectors or started to make bus bars or cell tabs get too hot and melt their insulation or risk thermal runaway in a cell. I believe the pack was designed way back when it was thought the Mach-E was going to be a compliance car only. With unexpected popularity, it was likely later decided to add a GT model, but it uses the same pack as the regular models to save on manufacturing costs. To make due with the existing pack design, "surge" capacity was added, similar in concept to overboost on a turbo car like the Focus ST.

The 4X premium draws up to 750A, while the GTPE draws up to 1050A IIRC. 750A is probably what the pack was designed for, so the extra 300A is an overboost with a moving average function applied in order to limit the power to a certain average during a timed window (e.g. 700A average over the past 10 seconds).

The proper way to fix this is to give the GT its own pack design with upgraded internals so higher currents can be maintained, similar to how the Model S Plaid has its own special battery with huge bus bars.

Enter….Shelby Mach E GTPE

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[Mach1E]

Enter….Shelby Mach E GTPE

When will it actually enter though? Even the prototype had zero power upgrades.

 

[kkriskal]

I just got a 2023 Mach E GT and even the 2023 models have the power limiter. So no change

 

[Mike G]

We need an HVJB that uses the same contactors that the Lightning uses.

When will Ford Performance start offering upgrades like that for the GT or GT PE?

Are there any engineers in the house?

Hello?

 

[silverelan]

We need an HVJB that uses the same contactors that the Lightning uses.

When will Ford Performance start offering upgrades like that for the GT or GT PE?

Are there any engineers in the house?

Hello?

It's been said more than a few times now that it's not the HVBJB that's the limiting factor, it's the battery pack itself. Something like 1080 amps is drawn when the GT is at wide open throttle but the pack is allegedly unable to sustain these high current loads for long without melting some important bits.

 

[JLowe]

It's been said more than a few times now that it's not the HVBJB that's the limiting factor, it's the battery pack itself. Something like 1080 amps is drawn when the GT is at wide open throttle but the pack is allegedly unable to sustain these high current loads for long without melting some important bits.

It would be interesting to know which “important bits” may be susceptible to high current loads. What’s the weak link? And then let me upgrade them (Not considering voiding warranty).

 

[Mach1E]

It's been said more than a few times now that it's not the HVBJB that's the limiting factor, it's the battery pack itself. Something like 1080 amps is drawn when the GT is at wide open throttle but the pack is allegedly unable to sustain these high current loads for long without melting some important bits.

This is the theory at least.

But no one here knows “how long” since the 5 second limit is so conservative that NO ONE has melted any “important bits.”

I would be more likely to believe the theory if a few cars broke due to wide open throttle runs.

Kinda like how we know a transmission or rear end is a weak link on an ICE vehicle when a few people blow those up.

But since no one is breaking anything from full throttle runs…… we have no clue what the weak link is…… or if there even is a weak link.

Ford created the 5 second rule due to the lack of temperature sensors in the battery. So rather than risk component’s overheating, they gave us a limit as a preventative measure.

But for us……. Lack of evidence against something isn’t evidence of the thing. Thus the “theories.” We can’t measure the temperature of the “important bits,” so people just ASSUME they’re in danger of melting.

 

[AKgrampy]

This is the theory at least.

But no one here knows “how long” since the 5 second limit is so conservative that NO ONE has melted any “important bits.”

I would be more likely to believe the theory if a few cars broke due to wide open throttle runs.

Kinda like how we know a transmission or rear end is a weak link on an ICE vehicle when a few people blow those up.

But since no one is breaking anything from full throttle runs…… we have no clue what the weak link is…… or if there even is a weak link.

Ford created the 5 second rule due to the lack of temperature sensors in the battery. So rather than risk component’s overheating, they gave us a limit as a preventative measure.

But for us……. Lack of evidence against something isn’t evidence of the thing. Thus the “theories.” We can’t measure the temperature of the “important bits,” so people just ASSUME they’re in danger of melting.

I will begin by saying I have no idea either how long it will take for the bits to melt or if they would even melt at all or rather just have component failure. I will say that we limit the ampacity of the wiring in our houses, etc without monitoring the wiring temp as the cables are rated for certain amount of current at certain temps. We do not have to burn down our houses to trust these limits. I assume the same is true for the battery pack or Ford is just idiotic and willing to be constantly bashed from a marketing perspective. Why they went with inadequately sized bus in a tight area without some form of active cooling in a performance edition EV is beyond me.

 

[A-A-Ron]

Why they went with inadequately sized bus in a tight area without some form of active cooling in a performance edition EV is beyond me.

This is my best guess: Remember that this car didn't start out as a Mustang - it was some Escape-sized EV that they decided mid-design to rebrand as a Mustang. It likely already had muscle car-like acceleration and maybe they tweaked it a bit to make it even quicker, but I'd wager there really wasn't much of a change there to the performance that was already there. Either way, I think the base model already ended up pretty well optimized for the power system it was designed for. Then someone had the idea of making a GT by including the larger rear motor on both the front and back and Ford ran with it. Problem was - the GT design was 6 months behind the initial non-GT releases and by the time Ford started testing the GT, the standard MMEs were in production. When they realized they couldn't sustain the power levels needed for the larger motor on both axels, it was way too late into the design to do much about it besides add a limiter. They likely made the assumption most purchasers aren't going to the track and 5s of full power will blast anyone past any street legal speeds so it wouldn't be a big deal. The only other alternative would be to completely reengineer the GT's entire battery and high voltage systems and that takes too long and costs too much for something they assumed wouldn't be noticed by that many people. Throw in covid-era supply chain issues, chip shortages, learning curves for manufacturing and service and putting in a different high voltage system likely wasn't even a viable option.

TL;DR: The GT design was too far down the road when they realized there wasn't much additional performance they could squeeze out of the standard 4X design.

 

[sotek2345]

This is my best guess: Remember that this car didn't start out as a Mustang - it was some Escape-sized EV that they decided mid-design to rebrand as a Mustang. It likely already had muscle car-like acceleration and maybe they tweaked it a bit to make it even quicker, but I'd wager there really wasn't much of a change there to the performance that was already there. Either way, I think the base model already ended up pretty well optimized for the power system it was designed for. Then someone had the idea of making a GT by including the larger rear motor on both the front and back and Ford ran with it. Problem was - the GT design was 6 months behind the initial non-GT releases and by the time Ford started testing the GT, the standard MMEs were in production. When they realized they couldn't sustain the power levels needed for the larger motor on both axels, it was way too late into the design to do much about it besides add a limiter. They likely made the assumption most purchasers aren't going to the track and 5s of full power will blast anyone past any street legal speeds so it wouldn't be a big deal. The only other alternative would be to completely reengineer the GT's entire battery and high voltage systems and that takes too long and costs too much for something they assumed wouldn't be noticed by that many people. Throw in covid-era supply chain issues, chip shortages, learning curves for manufacturing and service and putting in a different high voltage system likely wasn't even a viable option.

TL;DR: The GT design was too far down the road when they realized there wasn't much additional performance they could squeeze out of the standard 4X design.

I will add on to this that I suspect they thought the GT would be far more niche than it ended up being, so they didn't allocate a lot of engineering resources to it.

I seem to recall an article from a year or 2 ago saying they were surprised at the demand for the GTs.

 

[Mach1E]

This is my best guess: Remember that this car didn't start out as a Mustang - it was some Escape-sized EV that they decided mid-design to rebrand as a Mustang. It likely already had muscle car-like acceleration and maybe they tweaked it a bit to make it even quicker, but I'd wager there really wasn't much of a change there to the performance that was already there. Either way, I think the base model already ended up pretty well optimized for the power system it was designed for. Then someone had the idea of making a GT by including the larger rear motor on both the front and back and Ford ran with it. Problem was - the GT design was 6 months behind the initial non-GT releases and by the time Ford started testing the GT, the standard MMEs were in production. When they realized they couldn't sustain the power levels needed for the larger motor on both axels, it was way too late into the design to do much about it besides add a limiter. They likely made the assumption most purchasers aren't going to the track and 5s of full power will blast anyone past any street legal speeds so it wouldn't be a big deal. The only other alternative would be to completely reengineer the GT's entire battery and high voltage systems and that takes too long and costs too much for something they assumed wouldn't be noticed by that many people. Throw in covid-era supply chain issues, chip shortages, learning curves for manufacturing and service and putting in a different high voltage system likely wasn't even a viable option.

TL;DR: The GT design was too far down the road when they realized there wasn't much additional performance they could squeeze out of the standard 4X design.

It’s an interesting theory as well, but I also don’t really buy into this one.

Maybe super early on it wasn’t supposed to be a Mustang. But as soon as it was, they designed and intended it to be as true of a Mustang as possible. They wasted no time getting to work advertising 0-60 in 3.5. It wasn’t an afterthought.

 

[AKgrampy]

It’s an interesting theory as well, but I also don’t really buy into this one.

Maybe super early on it wasn’t supposed to be a Mustang. But as soon as it was, they designed and intended it to be as true of a Mustang as possible. They wasted no time getting to work advertising 0-60 in 3.5. It wasn’t an afterthought.

I do not know this for sure but I have a feeling it was an “Oh Crap” moment when the battery pack manufacturer notified Ford there was a 5 second power limitation.

 

[buzznwood]

I do not know this for sure but I have a feeling it was an “Oh Crap” moment when the battery pack manufacturer notified Ford there was a 5 second power limitation.

The original specs during the reveal for the GTPE had the following

• Mustang Mach-E GT Performance Edition brings the thrills Mustang is famous for, targeting 0-60 mph in the mid-3-second range and an estimated 342 kW (459 horsepower) and 830 Nm (612 lb.-ft.) of torque

Which was the same as the standard mustang GT, the final spec pushed that up to 480hp to match the mach-1, so did that mean we originally had more than 5 seconds of full power at 459hp lol.

Many a ford performance product has never got to see the light of day due to cost reasons and even ones that do make it into production can end up with changes as part x turns out being cost prohibitive so plans are changed but this is all happens long before marketing start shouting from the roof tops.

While I don't doubt there are some hardware limits this is this sort of thing they would have found out long before those first press releases if not and they really didn't bother to do any testing and only found out at which point it was too late it puts ford in an even worse light.

It is all water end the bridge now but with ford performance parts they at least have the option to correct the situation by offering some upgrades, those that don't care about the 5 second limits will be happy to stay with what they have while those that actually want a performance BEV will probably grumble over the extra cost but if means the GT/GTPE finally lives up to its potential then people will open up the wallet, after all it is supposed to be mustang which expect to do performance modifications to.

It is not like Ford have a back catalogue of performance BEVs for people to go oh well must have been a blip, when your first marketed performance BEV falls flat on its face the chances of people after a performance BEV even giving you a second look the next time around is slim.

Ford can't do much about the top speed of the GT/GTPE by when next year the cheaper Volvo XC30 will out accelerate your top performance trim it will no longer be a case of just being slower than vehicles in the same size class it will be slower than the class below it.

 

[BigMach-E]

All of this is supposition based. I am still in the camp that Ford will make a paid software improvement that will unlock some amount of performance on the GT that it doesn’t currently have. It’s just a theory, as well, but the motors are rated to have max combined BHP of 562. Why would you put a part that can put out more horsepower into the car, and never, under any circumstance, allow it to be tapped? The only part of the power train that has failed, on any MME GT, has been the originally underspecced HVJB. There is a new HVJB that I think has been either installed on the majority of MME GTs at this point, or they were built with it. There was some anecdotal evidence that there was a fire, on a pre production model, once during testing, on a really hot day, that caused the 5 sec limit to be put in place.

Do any MME GT owners still have the original HVJB design?

 

[sotek2345]

The original specs during the reveal for the GTPE had the following

• Mustang Mach-E GT Performance Edition brings the thrills Mustang is famous for, targeting 0-60 mph in the mid-3-second range and an estimated 342 kW (459 horsepower) and 830 Nm (612 lb.-ft.) of torque

Which was the same as the standard mustang GT, the final spec pushed that up to 480hp to match the mach-1, so did that mean we originally had more than 5 seconds of full power at 459hp lol.

Many a ford performance product has never got to see the light of day due to cost reasons and even ones that do make it into production can end up with changes as part x turns out being cost prohibitive so plans are changed but this is all happens long before marketing start shouting from the roof tops.

While I don't doubt there are some hardware limits this is this sort of thing they would have found out long before those first press releases if not and they really didn't bother to do any testing and only found out at which point it was too late it puts ford in an even worse light.

It is all water end the bridge now but with ford performance parts they at least have the option to correct the situation by offering some upgrades, those that don't care about the 5 second limits will be happy to stay with what they have while those that actually want a performance BEV will probably grumble over the extra cost but if means the GT/GTPE finally lives up to its potential then people will open up the wallet, after all it is supposed to be mustang which expect to do performance modifications to.

It is not like Ford have a back catalogue of performance BEVs for people to go oh well must have been a blip, when your first marketed performance BEV falls flat on its face the chances of people after a performance BEV even giving you a second look the next time around is slim.

Ford can't do much about the top speed of the GT/GTPE by when next year the cheaper Volvo XC30 will out accelerate your top performance trim it will no longer be a case of just being slower than vehicles in the same size class it will be slower than the class below it.

Gotta admit that EX30 looks very nice. Definitely on the short list for a future vehicle, pending more info coming out.

Edit: just looked again and the lack of a gauge cluster may be a deal breaker. I hate that.

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