Will Dual Motor architecture solve regen limit issue

[C12farmer]

I have seen many post about regen cutting out or severely dialed back after a shorter than expect stretch of downhill decent. Maybe I missed the post, but I'm not sure anyone every confirmed the exact reason. Was there a thermal limit being reached on some kind for a component like the inverter? Or are they just limiting it to protect the battery? I doubt the battery is reaching a thermal limit since that can take hundreds of kW charge for much longer than these downhill stretches.

Could it be the QM design be getting too hot and can't be cooled during long regens. sufficiently? I know the DM has direct oil cooling of the stator.

Has there been any mention about the DM inverter having improved thermal performance?

I'm sure all my questions will be answered once Out of Spec Kyle gets a hold of one for some long term testing.

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[Dark-Fx]

No

 

[MountainBikeDude]

I have seen many post about regen cutting out or severely dialed back after a shorter than expect stretch of downhill decent. Maybe I missed the post, but I'm not sure anyone every confirmed the exact reason. Was there a thermal limit being reached on some kind for a component like the inverter? Or are they just limiting it to protect the battery? I doubt the battery is reaching a thermal limit since that can take hundreds of kW charge for much longer than these downhill stretches.

Could it be the QM design be getting too hot and can't be cooled during long regens. sufficiently? I know the DM has direct oil cooling of the stator.

Has there been any mention about the DM inverter having improved thermal performance?

I'm sure all my questions will be answered once Out of Spec Kyle gets a hold of one for some long term testing.

On my own down hill tests, it always comes down to state of charge. The thermals never seem to be out of control, it's always been tied to my battery's state of charge. 60-80% you'll get a decent amount of regen before it walks you back, but 40 or even 30% and below I rarely see a hint of a block on the guages even after 15-20 minute regen stints.

 

[KootenayEV]

I just descended an 1100m pass on the weekend with 5000lb trailer and no regen limits either time. I’ve only had my truck 2 weeks but so far I haven’t seen an issue.

 

[rhumbliner]

This topic was covered here back in April and Rivian admitted it was a thermal issue. Rivian hasn’t announced whether or not the dual motor version fixes the problem so we’ll just have to wait and see.

 

[wwheelkid]

I just descended an 1100m pass on the weekend with 5000lb trailer and no regen limits either time. I’ve only had my truck 2 weeks but so far I haven’t seen an issue.

What state of charge were you when going down the pass. I was limited like after 3-4 minutes of downhill and I wasn't even going down that fast. Maybe 45 - 50 mph. I was very shocked that I got this notice at all - however my SOC was maybe 70 - 72 percent. Which may make difference..but still you would think there would be no until like 90% or so. I am assuming that Rivian is looking into this. But at some point, the hardware will be a limiting issue and not software. Hopefully we are not there yet.

 

[KootenayEV]

What state of charge were you when going down the pass. I was limited like after 3-4 minutes of downhill and I wasn't even going down that fast. Maybe 45 - 50 mph. I was very shocked that I got this notice at all - however my SOC was maybe 70 - 72 percent. Which may make difference..but still you would think there would be no until like 90% or so. I am assuming that Rivian is looking into this. But at some point, the hardware will be a limiting issue and not software. Hopefully we are not there yet.

46% the first day, 37% on the way back. One side is a bit steeper coming down the first few km’s from the top (the first day at 46%), and I did see a little hashed mark at the bottom of the regen meter for a few mins but it didn’t inhibit holding my speed; the other direction is overall steeper but I didn’t see any hashed marks at all.
I’ll be curious to see how the truck handles higher SOC and winter. I find my Model 3 quite conservative compared to my 2014 Leaf even with high SOC and/or cooler temps (ie 10C, not even freezing!)

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