Is the CCS charging network good enough?

Cactus

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The bigger the battery capacity, the faster the charging time. My experience charging my Model S using non-Tesla superchargers has not been good: The essence of s-l-o-w. Hope CCS chargers are better, but L2 is the same or barely better than what I have in my garage (240V 40-50A).
Rivian- If you are listening, please partner with Tesla to use their Supercharging infrastructure.
 

ajdelange

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Keep in mind that the important thing in understanding charging is the energy consumption of the car as compared to the capacity of the charger. For example, ABRP seems to think the R1T will pull a little more than 500 Wh for every mile. Thus if you are using one of the older CHAdeMO/CCS stations that can supply 50 kW you will be adding range at the rate of 50000/500 = 100 miles per hour and the newer 100 kW stations will give 200. The newer, larger 200 kW CCS stations will give 400 mi per hour and the fastest, 320 kW ones theoretically 640 with this latter implying a 400 mile charge in about 37 minutes if there were no taper. But, of course, there is taper (I find that the 50 kW CHAdeMO stations generally average 40). Note that my Model X uses 300 Wh/mi and therefore gets 167 miles per hour at a 50 kW CHAdeMO station. Because of their larger energy consumptions the Rivians and Cybertrucks need larger chargers than the current crop of 200 - 300 Wh/mi vehicles.
 

Cactus

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Yep. Would love to see more 200kw+ chargers out there. Taper is why I favor bigger batteries.
 

Cosmacelf

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What Cactus is referring to is that high current fast DC charging can only deliver full power when the battery is almost empty. As the battery fills up, the car tapers off power so as to not damage the battery. So a bigger battery would be able to accept more charge in any given medium to long period of time than a smaller battery since it would be able to accept full charge for longer before tapering.

A larger battery would indeed take longer to fully charge, but if both batteries were nearly empty, the bigger battery would be the first to have enough charge to drive 150 miles.
 

Cactus

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Thanks Cosmacelf. I couldn’t have described it better myself.
Taper or ramp down is what you do when pouring liquid from a pitcher into a cup. You can start fast, then taper the flow as the cup fills up.
Recharging batteries works similarly.
 

ajdelange

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That would be true if there were no correlation between battery size and the power required to move the car. This is illustrated in the graph below in which two variants of the CT, one with a 100 kWh battery and the other with a 225 kWh battery are represented by, respectively, the blue and green curves which show miles added vs charging times assuming each truck, requires 500 wH/mi. Note that ABRP rates each of the three at 485 wH/mi. The SC is assumed to charge at 150 kW until SoC reaches 30% after which it tapers as exp(-(SoC -30)/30) reaching 15 kW at 99% SoC.The curves show insignificant difference until the taper starts on the smaller of the two batteries. At 100 miles added the time difference is 3 minutes (out of 20). But it takes 30 minutes to add 150 mi to the larger battery and 54 to do the same with the smaller. And to charge the larger to 200 miles range requires 44 min as opposed to two hours for the smaller. This is what you all are talking about. Now the actual numbers will clearly depend on the taper profile and I make no representation this is the correct taper profile for any battery existing on the drawing board so its choice (made as it's easy to program) is intended to illustrate the concept only.

80
Now here's where it gets interesting. At today's specific energy levels more than doubling the capacity of the battery adds appreciable weight to the vehicle. The largest sink of energy in a vehicle is that which goes into its kinetic energy. In an EV much, but not all of this is recovered which means that the required Wh/mi go up with the battery size. This is why fuel cells may ultimately win out in electric trucks (Semi size). There are diminishing returns as more batter is added. The red curve in the picture represents charging with a Model X using 300 Wh/mi with a 100 kW battery. It picks up 150 miles in 11 minutes less than the CT with a battery over twice as large. Again, the curves shown here depend on the assume taper. The intent is to illustrate that battery size alone is not the only factor. Vehicle efficiency is also important.

One thing is clear and that is a battery chemistry that does not require taper or not so dramatic a taper would be very valuable. There seem to be two factors here. One is resistive heating and the other swelling of the anode. Better cooling could help with the former and a different chemistry with the latter. We know that Rivian has done a lot of research on the cooling aspect but we don't know anything about the batteries. With the CT's we know even less.
 
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Cactus

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Great graphic thanks!
Let’s hope battery chemistry and cooling strategies continue to improve.
 

ajdelange

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I'm back and forth between the CT (Cybertruck) and Rivian fora all the time and sometime forget which I am in and so used CT comparative data rather than Rivian which I could have as easily done but it doesn't matter really as the Rivian numbers would be as squishy as the CT ones. The message is that a larger battery is usually associated with a higher Wh/mi demand (that's why a designer puts a larger battery in) and so the idea that a larger battery gets you more miles faster is not as simply explained as one might at first think.

What typos?
 

Cosmacelf

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I'm back and forth between the CT (Cybertruck) and Rivian fora all the time and sometime forget which I am in and so used CT comparative data rather than Rivian which I could have as easily done but it doesn't matter really as the Rivian numbers would be as squishy as the CT ones. The message is that a larger battery is usually associated with a higher Wh/mi demand (that's why a designer puts a larger battery in) and so the idea that a larger battery gets you more miles faster is not as simply explained as one might at first think.

What typos?
it’s no big deal. Just my OCD kicking in.

”This is why fuel cells may ultimately win out it electric truck (Semi size)”
 

Cactus

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I read the EA article. Sheesh, what a mess. Imagine driving to an EA charger with less than 10% and hoping 1) the app works, or 2) your cc works on their reader, 3) the touchscreen works, 4) charging is not 50kW or slower.
Seems like they are trying to make the experience better, but why is it quadruple the cost of a supercharger visit? Despite being fined for cheating (dieselgate), VW has mountains of cash. Since VW has plans to electrify their fleet, why not make sure the charging experience is really really good?
You get the feeling that VW doesn’t really care too much about electrification, but they do care about making money. If they make charging too expensive they will shoot themselves and other EV makers in the foot. Most people that live in houses charge at home 90% of the time, but lots of people live in apartments and would depend on EA chargers.
 
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ajdelange

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The reason it costs so much more than a SuperCharger (to the point where my usual long trip will cost more in an R1T than in a Lexus SUV) is that Telsa does not (and says they never will) make a profit on the SC net. They don't have to. They can simply add the expected SC loss to the price of the car. The SC network was built as a marketing tool and it still is one as the pricing is set low enough that they don't have to add too much to the price of the car and I can still say that the same trip in the Model X will cost less than it would in the Lexus.

Now R.J. Scaringe is no dummy. When and if he sees this post he isn't going to slap his forehead and declare "Wow, I never thought of that!". He already is well aware of this and has noticed that not only has Tesla done this, but other manufacturers have too. Thus I think it likely that Rivian will, to at least some extent, subsidize charging on at least one of the networks and it's probably going to be EA since they have the largest network. With the ISO 15118 Plug and Charge standard coming on line (assume Rivian will be compliant) this should become an easy thing to mnage. EA must at least cover their expenses and that can't be done at the rates Tesla is charging but if Rivian foots the bill, or part of it, then EA can cover their expenses and the users will see a lower price at the pump. So expect to see free charging, perhaps for the life of the vehicle for the first buyers or free charging for a year or two or charging for Rivian owners at less than the current EA rates.
 

Cosmacelf

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@ajdelange - yes, hopefully Rivian will do this. However, they may not need to. They are only planning on selling 20,000 vehicles a year for the first year. Both the R1T and R1S fit market holes and I would expect them to sell well. If they do sell well, then Rivian won't need to subsidize charging. We shall see what happens. Certainly it is possible Rivian will subsidize.
 

Cactus

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I am just not impressed with Electrify America. Sure, they are fixing some problems, but do we really trust VW?
What are the obstacles to Rivian partnering with Tesla's SC network? Maybe RJ could call Elon and say, "Look, EA is charging people twice as much as it costs to drive an ICE car. If you really want to encourage adoption of EVs, let's make a deal on Rivian using Tesla's SC network."
 

ajdelange

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hopefully Rivian will do this. However, they may not need to. They are only planning on selling 20,000 vehicles a year for the first year.
Good point but then comes the second year and the third. Beyond that the panache that goes with electric vehicles wilts if you have to add "but they cost more to operate than similar ICE vehicles".
 

ajdelange

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What are the obstacles to Rivian partnering with Tesla's SC network?
There are, of course, some technical obstacles such as the fact that the SC stalls do not have CCS connectors. That's easily solved (and actually I think is solved in Europe). Then there are the software changes necessary to accommodate billing for the Rivian vehicles.

If you really want to encourage adoption of EVs, let's make a deal on Rivian using Tesla's SC network."
That's what he (Elon) has effectively said. But does he really, deep down, want his ingenious marketing tool to be used for the benefit of a competitor? Does Rivian want to be tied to a competitor in this way? Will Tesla users who are already being frustrated by wait times at inadequately sized SC's readily accept additional users who are not members of the club? All in all I don't think your question has a simple answer.
 
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