BriansTesla
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It seems to me that the some of the rest stops in Europe are what future charging stops might look like.
Tesla Opens Its Patents To Boost Electric Car Adoption
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It seems to me that the some of the rest stops in Europe are what future charging stops might look like.
Todd Burch
Voltage makes me tingle.
Why? Superchargers support *up to* 135 kw. They can always ramp down, which means a car with an an appropriate connector could have any sized battery and charge at any rate <=135 kW.
The distance between chargers is irrelevant too. If a large car company wants in on this deal for their 100 mile EV, fine...they'll just have to support putting the charging stations 50-60 miles apart. More choices for charging for us!
Do we know whether the car controls the charge rate (as with normal AC EVSE protocols) or the supercharger?
The issue is that if a car charges at, for example, 25kW, then it is going to block the charging station for much longer than one at 135kW. Similar case for the distance between stations (a car needing 50% charge gets away in significantly less than half the time of one needing 100% charge). Of course, offset that against smaller vehicle batteries requiring less kWh put into them.
The core design goal of the superchargers seemed to me that they were ideally spaced about 1/2 to 2/3 a 85kWh pack apart - that is not just to have a buffer for range, but because a 50% top-up charge is significantly quicker than a full 100% charge (due to current tapering at the high end of the pack).
Todd
The ramping down is due to the infrastructure cost needed for a 135kw grid pull can be pricey. For instance currently there are 0 DC3 chargers in MN (so maybe this is a bad example). I take an ice fishing trip once per year in Baudette MN. The last hour of that trip is pretty sparce, although Baudette is a decent sized town. Considering the size of the town, who is going to invest in a 150k charger? The current price of the Chademo is somewhere in the 10-15k price range. Granted 135kw is a lot more practical for the customer, but the Chadamo is a lot easier to make economic sense for the charging company.
The ramping down is due to the infrastructure cost needed for a 135kw grid pull can be pricey. For instance currently there are 0 DC3 chargers in MN (so maybe this is a bad example). I take an ice fishing trip once per year in Baudette MN. The last hour of that trip is pretty sparce, although Baudette is a decent sized town. Considering the size of the town, who is going to invest in a 150k charger? The current price of the Chademo is somewhere in the 10-15k price range. Granted 135kw is a lot more practical for the customer, but the Chadamo is a lot easier to make economic sense for the charging company.
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TonyWilliams
Active Member
The car ALWAYS controls the charge on modern electric vehicles. The only limit of the charger is the volts (100-500 volt DC) and how many DC amps it can deliver (over 300 on Supercharger)
A 25kW car may not block a Supercharger longer than an 85kWh one, if the former has only a 25kWh battery.
They both charge "in about an hour".
Bemidji, 100 miles away is slotted to get a supercharger in 2015.
Unless you are Ice Fishing from the Tesla, plugging it in at your destination shouldn't be an issue.
Smaller battery packs slowing down access to others is a concern. However, I believe it can be minimized in a number of ways.
For example, the most straight forward is to build more SC stations as other cars are allowed access.
Second, they could set one half of each pair of SC (e.g. 1B, 2B, etc) to be the designated 'slow' charger.
The 85kWh parks in the A slot while the 35kWh generic EV gets the B slot.
The B car gets 35kW while the 85kWh gets the balance.
The numbers may change, but you get the general idea.
stopcrazypp
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- Dec 8, 2007
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However, the 25kWh car probably can't make it to that supercharger anyways. And the actual mph charging speed is still low, so the supercharger is still underutilized (much better for that car to charge at a CHAdeMO or CCS charger). I think Tesla's power requirement is designed to keep the station density similar to what it is now and just scale by number of slots. This would make it less practical for local users from using it for daily charging (something that can easily make superchargers a money losing business just from the electricity alone).
It won't block a station more, but the problem is that it would block more stations.
I agree that is the way it should work, but we don't know for sure how it actually works with the Tesla SuperChargers. The reverse engineering efforts have made some headway, but not to that level of detail, and Tesla haven't released the details yet. We don't know how tightly coupled the SuperChargers are to Tesla vehicles. The SuperCharger protocol certainly doesn't seem to have been designed as an industry standard (unlike the signalling we see even on early Roadsters and compatibility with the later J1772 standard).
If 2 cars have to put a given kWh (equate to number of miles/kilometers range added) into their batteries, one does it at 25kWh, and the other at 135kWh, the first one will occupy the stall for comparably longer than the other. A 25kWh charger is going to block that stall for 4 times as long as a 100kWh charger. Put it another way - if two SuperChargers were spaced 50 miles apart, a car charging at 25kWh would have to charge for 4 times as long as one charging at 100kWh, to add those 50 miles of range.
When talking about vehicles with different battery sizes and charge rate limits, the correct way to think about this is not SOC% (and in particular not 0% -> 100% SOC), but in miles/kilometers of added range per minute at the charger.
WarpedOne
Supreme Premier
Chickenlittle
Banned
No whether it happened or not does not depend on link. That's like saying I saw it on the internet so it must be true
My own experience was seeing a signature car at Delaware supercharger over a year ago. I talked to the driver who had computer equipment hooked up to it. I congratulated the driver on his purchase but he told me BMW owned the car. It was taken up there on flatbed to measure how tesla superchargers worked. He also told me how BMW had been reverse engineering the car. He told me the car had to be fixed by tesla a couple of times because of those efforts and tesla was aware of their efforts. Yes did report it
stopcrazypp
Well-Known Member
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I think he means a link to show how the supercharger works (to the point where it proves it's the car that controls the charging, not the charger). That an automaker has done a large amount of reverse engineering is irrelevant to this given we don't have access to that data, so the question is still unanswered for us.
Not everything is necessarily published online, but you can read the start of efforts such as this one : Supercharger protocol for diy CHAdeMO adapter
Krugerrand
Is Cat
Todd Burch
Voltage makes me tingle.
A few points.
I'm virtually certain that the car controls the charge rate, not the Supercharger. I'll eat my hat and yours if I'm wrong. So any car can request whatever power level it wants, up to the max. Not sure if this is proven, but it makes so much more sense, and if not--what's the difference? The point is, the car that's charging (it won't always be a Model S in the future) must communicate with the station. The charger must somehow determine how much power to put out...the source of that information is the car.
About charger use:
On the one hand, unless the pack is REALLY big (in which the max power output of the Supercharger is far less than the pack can handle), battery size doesn't matter. Whether a pack is huge or small, charging at, say 1C takes the same time for both packs. And EV charge rate is capped by the C rate, because that's what impacts battery life.
On the other hand, markwj is correct in that, in general, smaller packs tend to have lower mph charge rates. Yes, smaller packs usually come on smaller cars, so their Wh/mi is typically less, but not enough to make up for the lower capacity of the pack. So, smaller packs would mean lower capacity charging not longer at a time, but more frequently.
I think, however, that any EV participating in this would probably have a range of ~100 or more miles. I think the increased demand for chargers if you add a lot of 100 mi range EVs into the mix would be properly balanced by an increased number of supercharger stations.
I'm virtually certain that the car controls the charge rate, not the Supercharger. I'll eat my hat and yours if I'm wrong. So any car can request whatever power level it wants, up to the max. Not sure if this is proven, but it makes so much more sense, and if not--what's the difference? The point is, the car that's charging (it won't always be a Model S in the future) must communicate with the station. The charger must somehow determine how much power to put out...the source of that information is the car.
About charger use:
On the one hand, unless the pack is REALLY big (in which the max power output of the Supercharger is far less than the pack can handle), battery size doesn't matter. Whether a pack is huge or small, charging at, say 1C takes the same time for both packs. And EV charge rate is capped by the C rate, because that's what impacts battery life.
On the other hand, markwj is correct in that, in general, smaller packs tend to have lower mph charge rates. Yes, smaller packs usually come on smaller cars, so their Wh/mi is typically less, but not enough to make up for the lower capacity of the pack. So, smaller packs would mean lower capacity charging not longer at a time, but more frequently.
I think, however, that any EV participating in this would probably have a range of ~100 or more miles. I think the increased demand for chargers if you add a lot of 100 mi range EVs into the mix would be properly balanced by an increased number of supercharger stations.
rogbmw
Member
Am I the only one that might not like this? As both a Model S owner, Model X reservation holder, and Tesla stock owner, the last thing I want to find if I am on a long trip and pull into a SC station on a trip is find a line of Non-Tesla cars waiting to use the SC? If they do this, then I feel that as a Tesla owner, there should be some way that we would receive priority.
Why would you assume they would not build to service the number of SC capable cars?
As a two Model S household and Model X reservation holder and stockholder I am incredibly excited about this. Think of how much faster the network can grow with contributions from other car brands.
Other brands will want SC closer to each other than 130-150 miles so those of us with more range will have more choices.
This will also speed the adoption of EVs in general, and Teslas in particular.
Of course, this is assuming any other manufacturers jump on board. And I don't think they will. The gift has been offered, but I suspect they are to stubborn to accept it.
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