Inside Electrify America’s plan to simplify electric car charging

Hmp10

Well-Known Member
The comparison of the Tesla charging costs to the Rivian costs on the same trip is very revealing. I take it this assumes charging the R1T at Electrify America stations, where rates are ridiculously expensive?

If I were planning on doing a lot of road trips, I would not even consider a Rivian. However, as with most drivers, the great bulk of my driving is local, and I pay 14 cents per kWh for charging at home, regardless of the time of day. At that price, the greater power consumption of the Rivian over a Tesla or any other EV is not enough of a factor to annoy me. If, however, it were combined with the exorbitant costs of using EA chargers with any regularity, I would back away.

When it comes to charging (time, cost, availability) right now, I personally am in the transition tunnel from ICE to EV. I'm already at the point where I would not be without an EV for efficiency and driving pleasure, but I'm not yet at the point I would be without an ICE for flexibility of use.
 
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ajdelange

Well-Known Member
Yes, it assumed, I think in every case, an EA charger. There really isn't any alternative. The relevant factors are
1)The Rivians gobble 500 wH/mi (compare to Tesla's 300)
2)That means more charge must be taken on per mile driven
3)That, in turn, means that if charging time is to be at all reasonable a very fast charger is needed
4)EA has the only fast (> 50 kW) chargers on the route I experimented with and EA charging is hideously expensive

Thus Rivian will have to subsidize charging one way or another if they hope to sell vehicles just as Tesla and the other manufacturers have done. This is because while most driving is done where home charging is available at much lower rates it is anxiety associated with longer trips that scares people away. Take away the offsetting good news that energy costs in an EV are lower and you have, IMO, a rather negative sales lookout. Cool factor only goes so far. And what about folks in condos and apartments that can't set up a home charger? Tell them that their shiny new truck is going to cost more to run than their ICE vehicle and they are gone.

A rather extensive survey study found that anxiety tends to evanesce once a driver actually begins using an EV but it is, nonetheless, the number two factor (No 1 being cost) that scares people away from EV's.
 

EVian

Active Member
For me personally, it all hinges around what range these vehicles will actually get on the highway. In the UK we have a lot of different suppliers of charge points, with the need to have numerous key fobs or apps to access the charge points, and, similar to the US it sounds, many that are 50KW or less. But if the range of the 135 KWh pack truly comes in at 300 miles on the highway (which with their theme of under promise and over deliver I’m hoping) then that would be fine by me in this little island of ours.
 

Hmp10

Well-Known Member
I have serious doubts that the advertised range of the Rivians will be realized in real-world driving conditions. My Tesla's advertised range is determined based on a steady speed of 65 mph on a flat road in temperate weather with no accessories running. When I drive it across Alligator Alley (a flat, straight, lightly traveled stretch of I-75 through the Florida Everglades) with the cruise control set at 76 mph and the A/C running, I consume 10 miles of indicated range for every 6 miles of actual range (using highway mile markers to gauge distance). And the Tesla is probably considerably more aerodynamic than the Rivian, which means driving at real highway speeds in a Rivian will exact even more of a range penalty compared to the nominal range rating.

I think advertised, or even EPA, ranges in electric vehicles are good for comparing one EV to another or one battery pack option to another, but their relationship to real-world driving is going to be very iffy. Every factor deviating from optimum -- terrain, temperature, precipitation, speed, driving style, traffic -- is going to impact range significantly. Of course, this is true for ICE vehicles as well. The difference is that if your gas tank is draining down faster than you expected, you can just stop at the next gas station. It's not that simple yet with EVs.

This is why, as much as I love my EV, I do not yet view any of them as suitable for a lot of long-distance driving.
 

ajdelange

Well-Known Member
Once you start driving a BEV your perspective will probably change. Evidently, and certainly this was the what I found, 300 miles is more that enough range. Apparently many Tesla owners come to realize that they would have been just as happy with one of the smaller battery pack options especially as they would have saved some money. I find myself thinking that way but justify my decision by rationalizing that its always good to have some extra miles "in the bank" though people with the largest batteries do manage to get themselves stranded.

New to all this I jumped at the Rivian's 400 mile advertised range. After driving a Tesla for 8 months I have come to realize that I don't really need its 300 mile range. But I'll still get the 400 mi Rivian. If that doesn't make a lot of sense to you, well, it doesn't make a lot of sense to me either.

What I have really learned (from this thread) is that the most important factor appears to be not so much the range but the wH/mi. wH/mi (or rather its reciprocal - mi/wH) is akin to mpg in a ICE vehicle. If you have a gas guzzler with a small tank you have to top it off frequently. If you have a gas guzzler with a big tank you don't have to top off so often but it takes longer to top off. That's the situation with the Rivians. They are electricity guzzlers with big tanks and so it takes a long time to charge them relative to the smaller BEVs especially given that the "pumps" are so slow relative to petrol pumps. The other aspect is, of course, that fuel costs will be high.

As to your "little" (but sceptered) isle I suggest you put some trips into Abetterrouteplanner to see what you might experience. I tried Penzance to Inverness. The result was not unlike Cleveland to Disneyworld. 17:19 total with over a third of that dedicated to charging and the reason is, as you anticipate, 50 kW superchargers.

I also tried Penzance to Paris. Better there because once you get off Le Shuttle there are higher powered charges available.
 
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Hmp10

Well-Known Member
I've had a similar experience. Although my 2015 Tesla only has 257 miles of advertised range, it's virtually impossible for me to burn through much more than half of it with any amount of local driving in a single day. One day I picked up a friend for a series of errands. We were in the car for over five hours in all kinds of traffic (city streets to interstates) with numerous stops. I returned home with over 40% charge still on the car.

I soon lost all range anxiety for any kind of local driving.

However, I can drive across the state from Naples to Miami, run around the Miami area, and return home using a little more than half a tank of gas in my Honda Odyssey. In the Tesla, I would have to recharge in Miami before returning home. Fortunately, there is a supercharger on the outskirts of Miami on my return route. However, I have twice found only one spot available when I showed up. If it were off line for any reason, I would have to drive back into Miami through heavy traffic to get to another one. While I enjoy driving the Tesla more, over time I find myself opting more often to drive the Honda when heading over to Miami just so I don't have to worry about charging.

I, too, am going to opt for the 180 kWh pack on the R1S. It might be overkill for local driving but, given the size and weight of the Rivian, I just want to sure I never have to think twice about it. Whether it will be the vehicle I choose for drives across the state will depend on my actual experience once I have it.
 

ajdelange

Well-Known Member
I have serious doubts that the advertised range of the Rivians will be realized in real-world driving conditions. My Tesla's advertised range is determined based on a steady speed of 65 mph on a flat road in temperate weather with no accessories running.
It's based on an EPA protocol which includes a mix of highway and in town driving.

When I drive it across Alligator Alley (a flat, straight, lightly traveled stretch of I-75 through the Florida Everglades) with the cruise control set at 76 mph and the A/C running, I consume 10 miles of indicated range for every 6 miles of actual range (using highway mile markers to gauge distance).
Just to get a rough number lets assume that the EPA rated rate is equivalent to actual miles. This says you are running something like 60% efficiency. If you look at Stats (this is a third party app that collects statistics from subscribing Tesla drivers) statistics it shows that the average S driver gets 90% efficiency. I see lots of posts from Tesla drivers getting 75% and less efficiency and am still trying to understand how they do it. It's easy to blame the A/C but it can't take more than a ton of air conditioning to keep the cabin of the car cool even with solar load. That's about 750 watts spread out over an hour, 750 watt hours. Driving 76 mpH my X would consume about 29 kWh. The A/C load is thus about 3% of the traction load and I would expect my efficiency to drop to perhaps 95%. But 60%?

I'd like to make it very clear that it is possible to attain mileage as good as or better than the rated mileage though most don't realize that. I am an older guy and, I suppose, drive to some extent like a little old lady. More than advancing senility is perhaps "hypermiling" habits instilled when gas was over $3 a gallon. My overall average (including winter when efficiency does go down for several reasons) consumption is 299 wH/mi and the car is "rated" at 316 thus my overall efficiency is 105.6%. In warmer weather (never use the A/C except to precool when parked in the sun) it goes up to 110.9%. Stats shows average efficiency for X drivers to be perhaps 86%. So for conservative planning I'd use around 85% of the EPA range while realizing that a bit of attention to your driving can get you to or above EPA rated range. This means resisting the impulse to leave the young punk in the ICE muscle car in the dust (yes, we all do that from time to time), using regenerative braking to the max and, mainly, slowing down.


And the Tesla is probably considerably more aerodynamic than the Rivian, which means driving at real highway speeds in a Rivian will exact even more of a range penalty compared to the nominal range rating.
Doubtless but that gets picked up in the EPA testing. It also gets picked up in 550 Wh/mi estimate for Rivian's consumption.

I think advertised, or even EPA, ranges in electric vehicles are good for comparing one EV to another or one battery pack option to another,
That is exactly what they are designed for.


but their relationship to real-world driving is going to be very iffy. Every factor deviating from optimum -- terrain, temperature, precipitation, speed, driving style, traffic -- is going to impact range significantly.
This is where the "art" of driving a BEV comes in. With experience you will learn, for example, that heavy rain can drop your efficiency from near 100% to near 75% whereas use of heat or the A/C doesn't make that much difference nor does driving with the windows open (increases drag but not by that much). Tesla's real time driving displays take terrain into account and I certainly hope that Rivian's will too.

Of course, this is true for ICE vehicles as well. The difference is that if your gas tank is draining down faster than you expected, you can just stop at the next gas station. It's not that simple yet with EVs.
There is an ICE vehicle where the situation is the same and that is an airplane. If you have pilot training you will already know how to manage a BEV.


This is why, as much as I love my EV, I do not yet view any of them as suitable for a lot of long-distance driving.
I am of the opposite view no doubt because my driving experience is evidently different than Hmp10's. People use their cars in diverse ways and for a variety of purposes. I can readily see that there would be applications where the current BEV system is not adequate. I'm retired and never have to be anywhere at any particular time (exception: doctor's appointments) and the BEV is simply a joy.
 

ajdelange

Well-Known Member
However, I can drive across the state from Naples to Miami, run around the Miami area, and return home using a little more than half a tank of gas in my Honda Odyssey. In the Tesla, I would have to recharge in Miami before returning home. Fortunately, there is a supercharger on the outskirts of Miami on my return route. However, I have twice found only one spot available when I showed up. If it were off line for any reason, I would have to drive back into Miami through heavy traffic to get to another one.
From what you have said in previous posts I'm guessing that you are referring to the SC at Plantation. Were I to find that unavailable I wouldn't go back to Miami. I'd go to one of the nearby CHAdeMO chargers at Vizcaya, Sunrise, Pembroke etc. I'd also like to point out that having to wait at a SC, though I've never experienced it, doesn't sound as bad as it might at first seem. People are, on average, at super charges less than half an hour so you won't have to wait too long to get a stall (any wait is really too long) and the fear that you will only get a kW or 2 in a paired situation is unfounded as a cars that are nearing the end of charging are drawing less than they do at the beginning making more available.

While I enjoy driving the Tesla more, over time I find myself opting more often to drive the Honda when heading over to Miami just so I don't have to worry about charging.
If the fear of or certainty that you will have bad experiences charging outweighs the pleasure you take in driving the EV then you are doing the right thing. I'm still on the honeymoon and I look for any excuse to drive the Tesla. But I do a lot of "What if the SC at Plantation isn't available?" thinking. That's the old pilot in me.
 

Hmp10

Well-Known Member
I dug up some old posts back from the time I bought my Tesla in 2015. It was "Consumer Reports" that tested range at 65 mph with the criteria I described, not the EPA.

This is an interesting article on how EPA range is calculated on EVs:

https://teslike.com/range/

This passage comments on Model S/X range:

"EPA rated range = 0.7 * [(EPA city dyno test * 0.55) + (EPA highway dyno test * 0.45)]

In the formula, the 0.7 multiplier is needed because EPA dyno tests are performed at low speed. The city test is performed at 21 mph and the highway test at 48 mph average speed. This results in unrealistically high range numbers. Therefore they apply the multiplier to convert the numbers to more realistic numbers. So far, all EV manufacturers have used the 0.7 multiplier except Tesla. Tesla actually uses 0.7 too but only for the Model 3. They use higher multipliers for S/X to inflate the numbers. More information about this can be found here."

If this situation still prevails, the question will be what multiplier Rivian applies to dyno tests in order to calculate EPA range.
 
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Hmp10

Well-Known Member
I'm retired and never have to be anywhere at any particular time (exception: doctor's appointments) and the BEV is simply a joy.
I'm retired, too. This is just a matter of personal preference, I suppose.

My brother (also retired) is a bigger EV addict than I. He had to wait almost two years for the Model 3 dual-motor he ordered, and he could not wait to start traveling in it. He absolutely loves the car but, after several road trips in it, he has reverted to his Honda Accord for most of those trips.

He's twice driven his Model 3 from Atlanta to Naples. But charging stops add around two hours to what is already a 10-hour trip, and he finally just found the extra time too wearing. He recently took a trip from Atlanta to Savannah and wanted to drive his Model 3. However, he found that the only supercharger in Savannah was not very close to where he was going to be spending his time so, once again, it was the Honda he took. I suggested checking for destination chargers, but he concluded they were just too slow to be of much help, given his plans to be on the move so much.

If the point is to drive the EV, then certainly one can take a trip almost anywhere one wants these days. If time or convenience enters into the equation, the choice between taking your ICE vehicle or your EV on a trip becomes more complicated.
 

ajdelange

Well-Known Member
"EPA rated range = 0.7 * [(EPA city dyno test * 0.55) + (EPA highway dyno test * 0.45)]

In the formula, the 0.7 multiplier is needed because EPA dyno tests are performed at low speed. The city test is performed at 21 mph and the highway test at 48 mph average speed.
The dynamometer tests are performed at 0 speed. The dynamometer is a fixed device. The car is not moving. Drag is not accounted for. Road friction is not accounted for. Power loss/recovery in going up and down hills is not accounted for. Head and tail winds are not accounted for. Snow on the ground is not accounted for. Unusually high and low temperatures are not accounted for. A modern chassis dynamometer can be programmed to simulate some of these and they do. I expect that the EPA has elaborate specifications of what is to be programmed and how. Nevertheless a dynamometer in fact can only measure power delivered to the wheels as a function of torque and speed and, most importantly, the power required of the battery to deliver that. Converting these data to range requires some math involving things like drag, rolling resistance, efficiency of regeneration, battery characrteristics etc. Were the manufacturer given a free hand in picking his "fudge factor" then the EPA rating system would be useless. Thus we can surmise that while the manufacturer may be the one who determines what the fudge factor is that there are some pretty stiff requirements that he satisfy the EPA that his choice is justified. The bottom line is that, in the case of Tesla, the numbers seem to be pretty good as the average driver seems to be able to hit about 97% of the EPA range in mild weather, about 86% in cold weather and about 94% overall. I think we can assume that Rivian will be held to the same standard. I do.

I think we can also be pretty certain that the manufacturer knows that if the average drive got 60% of the EPA rating there would be a class action suit for false advertising. This also motivates him to pick his fudge factor wisely.
 
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EVian

Active Member
My PHEV only gets about 15 miles on electric alone, so I’m quite used to hypermiling it (my commute is just under 13 miles and in the colder part of winter I need to be very careful to make it without the engine kicking in). That said, the only times I’m likely to be travelling >100 miles is family trips, and they will be less willing to accept a more sedate pace of travel. We do need to make stops though (kids and dog) so being able to charge en route shouldn’t pose a challenge, it’s just the speed of charge or availability of chargers that might be an issue.

I’ll check out ‘a better route planner’, thank you, although Zap-Map does a similar thing (but without the estimate of duration I think).

My hope on range though is that the ranges quoted, AIUI, aren’t based on EPA, or WLTP etc, and are quoted as ‘300+‘ for example, but yes given their Cd is significantly worse than the Teslas, maybe the quoted ranges are going to be similar to EPA ranges, and I’m just living in cloud cuckoo land !
 

ajdelange

Well-Known Member
I seem to remember seeing some Cd numbers for the Rivians and they weren't too bad. I may not be remembering that right though. But Cd isn't the whole story behind larger Wh/mi. Drag, which is a major contributor, depends on Cd and sectional area and clearly the boxy Rivians have bigger cross sections than the Teslas. Mass also comes into it as do motor efficiencies etc. Tesla's new motors are really impressive in the high 90's on efficiency.

They will be forced to publish an EPA rated range if they want to sell in the States and, as I noted above, the EPA numbers are pretty good. And you can best them if you try and conditions (head winds, snow, extreme temperature) aren't against you.
 

Hmp10

Well-Known Member
The dynamometer tests are performed at 0 speed. The dynamometer is a fixed device. The car is not moving.
I have a feeling the author of the article knows that and am pretty sure he assumed readers would know that the car wheels while on the dynamometer were rotating at a rate equivalent to 21 mph and 48 mph on the road.
 

ajdelange

Well-Known Member
I would hope so. Just trying to make it clear that the dynamometer tests are intrinsically pretty basic, that the art is in calculating the fudge factor(s) and that, despite all this, the EPA numbers are pretty indicative of what you can expect if you know how to interpret them.
 
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