Is the gt ever going to get a charging curve update?

[silverelan]

There's a lot of people more versed in battery chemistry than myself. The 95F temperature has been discussed by myself many times on this forum. Yes, the MME likes to keep temps at a max of 95F.

My understanding is that as temperatures increase above about 77F charging speed is actually reduced. So I assume you are asking why can't the MME let the pack get hotter? Based on my understanding that would actually show things down. There's a crossroad where it's more beneficial to expend energy in cooling than increase temperatures at a slower rate.

Thanks for the explanation. Seems odd to me since I was under the impression that the MME pouch cells were identical to the VW ID.4's.

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[Mach-Lee]

@DevSecOps, @benk016, @breeves002, @scoopman, maybe you guys would know better than most.

if the MME ER packs are only hitting 33-35C temps while charging, then it seems to me there’s a decent amount of room for increasing the charging power?

The spec for DCFC is 25-45ºC. Ford has chosen to target the center of that range, 35ºC while DCFC. Since the rate of chemical reactions is proportional to temperature, higher temps allow faster and more efficient charging, but the expense of degrading the cells quicker as well.

The limitations on the charging rate are not due to cell temperature. More likely it is simply limited out of concern for cell durability. The current charging curve is still very conservative, I think it could be improved quite a bit without too many negative consequences. I would like to see a 300A constant current up to 75% or so, and only throttle if the battery temp reaches 40ºC.

 

[silverelan]

The spec for DCFC is 25-45ºC. Ford has chosen to target the center of that range, 35ºC while DCFC. Since the rate of chemical reactions is proportional to temperature, higher temps allow faster and more efficient charging, but the expense of degrading the cells quicker as well.

The limitations on the charging rate are not due to cell temperature. More likely it is simply limited out of concern for cell durability. The current charging curve is still very conservative, I think it could be improved quite a bit without too many negative consequences. I would like to see a 300A constant current up to 75% or so, and only throttle if the battery temp reaches 40ºC.

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[DevSecOps]

higher temps allow faster and more efficient charging, but the expense of degrading the cells quicker as well.

I was thinking of nickle based batteries .... I knew someone would correct me.

For lithium-ion isn't the limit about 122F before they start gassing off, venting, swelling?

 

[Mach-Lee]

I was thinking of nickle based batteries .... I knew someone would correct me.

For lithium-ion isn't the limit about 122F before they start gassing off, venting, swelling?

Yes, slow charge limit is 50ºC/122ºF. Bad stuff won't start happening until above 55-60ºC/131-140ºF. Charging at normal temps can sometimes still cause swelling, especially as the cells age.

 

[babgvant]

I’m really curious if anyone has done a comparison between 350kW and 150kW chargers? I can’t say for sure, but my hunch is that it has a higher average charge rate for 20-30 mins on the 150kW.

https://www.macheforum.com/site/thr...get-a-charging-curve-update.19967/post-478813

Not a statistically significant sample: ~40-80% took about the same amount of time on a 350 as a 150 kW, 350 peaks higher.

 

[ridgebackpilot]

My GTPE was built on 6/30/22 so presumably it has the updated HVBJB hardware and charging curve. It's not subject to the battery contactor recall.

I consistently see charging rates around 40 kW above 80 percent SOC while DCFC on long trips. So newer cars must have the new charge curve baked in.

Towards the end of his latest video, Professor John Kelly of Weber State provided a clue why we never see 150 kW or greater charge rates on Electrify America 150 kW DC fast chargers. According to Prof. Kelly, these chargers have an output limit of 350 amps (see attached). 400-volt HVB systems like ours require 375 amps to charge at 150 kW, which the EA chargers can't provide. Thus the highest charge rate we're likely to see from EA 150 kW chargers is around 140 kW. Presumably the 350 kW chargers are rated to deliver far more amps.

 

[mkhuffman]

My GTPE was built on 6/30/22 so presumably it has the updated HVBJB hardware and charging curve. It's not subject to the battery contactor recall.

I consistently see charging rates around 40 kW above 80 percent SOC while DCFC on long trips. So newer cars must have the new charge curve baked in.

Towards the end of his latest video, Professor John Kelly of Weber State provided a clue why we never see 150 kW or greater charge rates on Electrify America 150 kW DC fast chargers. According to Prof. Kelly, these chargers have an output limit of 350 amps (see attached). 400-volt HVB systems like ours require 375 amps to charge at 150 kW, which the EA chargers can't provide. Thus the highest charge rate we're likely to see from EA 150 kW chargers is around 140 kW. Presumably the 350 kW chargers are rated to deliver far more amps.

Another Forum member reported that some newer EA 150kW chargers actually have a 500 Amp limit. It is the older EA chargers that are limited to 350 Amps.

 

[YouEeee]

My mach built on 7/29. Mine is shown 38kwh after 80% , it gonna take almost 50 mins to 100% from 80 . Crazy

 

[mkhuffman]

My mach built on 7/29. Mine is shown 38kwh after 80% , it gonna take almost 50 mins to 100% from 80 . Crazy

You could be on a crappy DCFC. I assume your mean you car is a 2022 and it definitely has the improved charging curve, so it is most likely the charger that is limiting the power, not your car.

If you mean you have a 2021, you will get the new charging curve in one of the updates is included in the recall software update. I got mine before the recall update, so it is a prior update that is included if you didn't get it before.

 

[Maquis]

My mach built on 7/29. Mine is shown 38kwh after 80% , it gonna take almost 50 mins to 100% from 80 . Crazy

At 38 KW, you will reach 90% in 14 minutes. There will be more slowing once you hit 90%. IMO, there isn’t much of a case to DCFC above 90% except in extreme cases.
The old curve maxed at 12kw above 80%.

You could be on a crappy DCFC. I assume your mean you car is a 2022 and it definitely has the improved charging curve, so it is most likely the charger that is limiting the power, not your car.

If you mean you have a 2021, you will get the new charging curve in one of the updates is included in the recall software update. I got mine before the recall update, so it is a prior update that is included if you didn't get it before.

The new curve gives about 45KW best case above 80%. 38 could be normal variation due to any number of factors.

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