Rivian Battery Reveal- Sandy Munro Live

[thrill]

Yeah, I was ball parking it with the 30+% and that was a bit high. Actually, I think the Rivian range estimate on the large pack R1T is 314 miles, which stretches the 11 modules a wee bit more.

FWIW, how about this math? What am I missing?

314 miles/9 modules =34.9 miles per module.

34.9 miles per module x 11 modules = 384 miles.

34.9 miles per module x 12 modules = 419 miles

Sadly, the more weight you carry then the more energy overhead to carry that weight, so this is not going to be a linear calculation. (Really) hand waving here, but Car and Driver says the battery pack weighs 1755 pounds, which means rounded up that each module weight about 200 lbs (including their overhead of frame, wiring, etc). So, going from 9 modules to 12 modules means 600 extra pounds, which on a 7173 lb vehicle is about 12% more weight.

Taht extra weight will have the least negative effect on long trips, since the slower you're going then the more energy needed to go faster, until parasitic drag becomes a significant factor of course.

While these guys Vol15SP1 (emu.ee) go through the math in enough detail to make our electrical engineers quietly dispense tears of joy, the guys at Analysis of Parameters Influencing Electric Vehicle Range (sciencedirectassets.com) were kind enough to make graphs, and eyeballing the ones on page 172 gives me a rule-of-thumb that a 50% weight increase (keeping the same battery) means about a 25% range decrease.

I *think* we can extrapolate that to mean we only get about half the expected range increase with more (heavier) batteries.

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[Singletracker]

Sadly, the more weight you carry then the more energy overhead to carry that weight, so this is not going to be a linear calculation. (Really) hand waving here, but Car and Driver says the battery pack weighs 1755 pounds, which means rounded up that each module weight about 200 lbs (including their overhead of frame, wiring, etc). So, going from 9 modules to 12 modules means 600 extra pounds, which on a 7173 lb vehicle is about 12% more weight.

Taht extra weight will have the least negative effect on long trips, since the slower you're going then the more energy needed to go faster, until parasitic drag becomes a significant factor of course.

While these guys Vol15SP1 (emu.ee) go through the math in enough detail to make our electrical engineers quietly dispense tears of joy, the guys at Analysis of Parameters Influencing Electric Vehicle Range (sciencedirectassets.com) were kind enough to make graphs, and eyeballing the ones on page 172 gives me a rule-of-thumb that a 50% weight increase (keeping the same battery) means about a 25% range decrease.

I *think* we can extrapolate that to mean we only get about half the expected range increase with more (heavier) batteries.

Exactly! My calculations were pretty basic and did not take into considerations such things as added weight. All the more reason it may, given the current battery tech, take 3 additional modules to get past 400 miles. And, holy Hummer, Batman! The R1T will be pushing 8000 lbs.!

 

[jjwolf120]

page 172 gives me a rule-of-thumb that a 50% weight increase (keeping the same battery) means about a 25% range decrease.

I *think* we can extrapolate that to mean we only get about half the expected range increase with more (heavier) batteries.

I think your math may be a bit off, since the vehicle weight would only be increased by about 8%.

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