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Tesla Motors Charging Network

I have seen some mention in this forum about Tesla's plans to deploy their own charging stations. I was wondering if anyone actually had more information on this. Where did this information/rumor come from? Was there any mention of when, how many and where these would be? Any speculation on where they should put them?

The obvious answer for me would be to have them along freeways between their retail/service locations with an interval of about 100 miles but that would take a very large number of them.

Could non-Tesla cars charge at these locations? So many questions. They all might become irrelevant if a large public charging network will appear but will either be in time for the Model S reservation holders to use when we get our cars?

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@MitchL, battery tech is not the limiting factor, there are techs that allow less than five minute charging. Way less in fact.

Power needed to do such charging is a limit. In order to fill up 85kWh in ten minutes you would need enormous power from charger, and that is a currently unsolvable problem. 6*85kWh = 510kW of power or 510V@1000A = Too heavy cable to handle. Increase voltage to make amps manageable: 1700V@300A = too high voltage for safe charging.

But in reality that is not a problem. You can charge at home, which means you need fast charging very rarely. That also means that with 300mile battery you can drive something like 200miles before even starting to look for charger and at 75mph that's 2h40min of driving. Take a break and use ~30minutes in 45minute charger.

@Timo: I know you're exactly right, but I have to blink three times when I see statements like "1700V ... too high". My work is almost exclusively with the transmission system, and anything below 69kV is considered "small." It's certainly not the kind of voltages, however, that you want consumers handling.

Although, a short story about high voltage lines near consumers comes to mind. After the 9/11 attacks, ConEd of NY was faced with a huge problem: the major distribution hub for the south side of lower Manhattan was located in vaults beneath 7WTC; this hub was, obviously, completely destroyed when 7WTC collapsed in the wake (literally) of 1&2WTC. ConEd had crews laying temporary cables, connecting the substation at South Street Seaport over to the west side -- cables running at 345,000V, in wooden boxes in street gutters. Desperate times call for desperate measures.

Heh. I just got this image of charging stations made up to look just like gas stations, with HV transformers shaped like gas pumps, and the cable looking just like the gas hose, and the connector shaped like the gas handle. Insert, pull the trigger grip, it locks in for 5 min., done!

Maybe not so far-fetched. Didja know the reason light bulbs screw in instead of snapping in is that the first sockets were converted gas-lamp holders, that had that threading? Old habits shape new technology ...

Just received my January 2012 issue of AAA Travler. AAA is launching a pilot program providing roadside charging for EVs. They will provide trucks with level 2 and level 3 roadside charging capability in six metropolitan areas (as yet unnamed). These trucks will also be capable of providing AAA's full range of roadside assistance. They expect 1.2 million EVs on the road by 2015!

Hmm, I may need to renew my long-lapsed AAA membership.

That may push me into finally getting AAA.

No spare. No jack. Definitely keeping my AAA membership current!

Timo,

Great info on charging technology - thanks! Moving lots of energy in a short time will certainly test barriers imposed by the laws of physics,

In my musing about fast chargers, I was considering the I-5 corridor or other long interstate case (not local driving). 300mi EVs are imagined to be good for trips other than local rides in town.

If you've got 1000 EVs traveling from SF to LA on I-5 (so they _must_ stop to charge), and it takes 30 minutes to charge (today's tech), assuming an even distribution of arrival times for cars and a full 30-minute charge per car over the day you'd need 28 spaces at each station.

At least I think that's right.. I should ask my wife, she builds queueing models as part of her job and could confirm this.

I guess what I'm getting at is if all of a sudden 1% of the traffic on a busy interstate like I-5 was EV traffic, we'd need quite a bit of charging infrastructure.

/Mitch.

Re: AAA

FWIW, AAA allows you to sign up on the phone and immediately call them for help. No need to sign up in advance.

"If you've got 1000 EVs traveling from SF to LA on I-5 (so they _must_ stop to charge), and it takes 30 minutes to charge (today's tech), assuming an even distribution of arrival times for cars and a full 30-minute charge per car over the day you'd need 28 spaces at each station."

And maybe in 5 years as battery technology improves to a 400 mile battery that can take 240 miles of charge in 30 minutes, the number of charging spaces will be reduced by 33 %.

I can imagine a scenario that as fast as the number of EVs increase battery & charging technology will also be increasing so that the number of charging stations will not need to increase that much.

@Mitch;
Missing number -- how many charging stations are you positing? You've set up a demand for 500 charge-hours. Taking a 15-hr day for driving, that's 33 charge hookups. If there are (e.g.) 3 stations, that's 11 connections/station. Etc. Allowing for slack, 12 connections. To cut it down to 4 connections/station, you need 9 stations, mostly clustered near the middle of the route.

GoChicago;
Not all cars would have upgraded batteries just because there's new tech; most current buyers would/will/plan to hold on to original batteries as long as they don't fall below some personal usefulness borderline.

OTOH, the observed energy density jumps for LiIon in the last two years (2.9 - 3.4, 3.4 - 4.0) have both been 17%. 5 years of that gets you to >600 miles, which seriously cuts the need for fast-charge, as it's right up near the maximum daily driving limit, thus permitting overnight regular recharging (even L2 would do it in 8 hrs.) (That's all assuming running the batteries right down to empty, Range Mode, not a usual eventuality.)

I have sometimes wondered if it would be feasible to have kind of "better place" -type service station, but without actually swapping the battery, instead use that robotics to open a very high amp connector at floor of the car and charge using that. It would make this 5-10 minute charging entirely feasible, and also without need to swap batteries it could be a lot cheaper too, and less logistical nightmare.

Other way to do fast charging would be using high voltages. That would then require batteries in the car connected in a way that gives a lot higher voltage than Model S has for really fast charging. It is possible to make high voltages@amps safe, but it is not something to do lightly.

Both would obviously need either huge connection to grid or stored energy to batteries at the station refilled when not in use.

The battery life would be shortened with extremely high voltage or high current charges.

Yes, but effect is not that big in modern batteries, and ten minute charging is not actually extremely fast for some chemistries.

(my FF updated and now it refuses to change proof read language back to english, so I might make more typos than usual in next few messages).

My Tesla rep said they plan to make an announcement about the charging network sometime in March.

I think Brian h has it right. Just to add my thoughts. In ten or fifteen years, battery technology will be at a place where 1,000 mile ranges will be the norm. At that time, the need for roadside charging will be pretty much strictly be for commercial applications (imagine when 18 wheelers go electric). I can't see people making huge investments in stand alone roadside chargers for a short term problem.

Alternatively, the best solution is for existing gas stations to add high speed chargers. The real estate and electricity problems are solved and the economics of a gas station is they do not make much money selling gas - the money is in the food sales. Some smart gas station owners will get that.

I don't think long-haul 18-wheelers will ever be BEV:s. Those require just too much power to charge in any relatively reasonable time, and distances those are driven are huge. Power requirements for those to maintain highway speeds are easily 15-20 times bigger than passenger vehicles, so 1000 miles for that means 85kWh * 20 * 3.3 ~= 5.6MWh. In order to charge that in less than a hour you need more than 5.6MW connection.

I bet those will be fuel cell vehicles. Preferably with fuel in liquid form, like methanol or similar.

Or they will use DPF reactor as power source ;-)

I don't think those are problem in the long run. In worst case those can be run using ICE and biofuels.

In shorter term biggest need for chargers is with city dwellers that don't own a garage. Charging points need to be just about everywhere to make BEV useful for them, and there is a problem to solve about who pays and how much for that kind of charging. Those chargers don't necessarily need to be super fast, but they need to be widely available.

Charging points need to be just about everywhere to make BEV useful for them, and there is a problem to solve about who pays and how much for that kind of charging. Those chargers don't necessarily need to be super fast, but they need to be widely available.

Lord knows I often have a hard time finding a place to charge my phone in an airport; getting sufficient coverage for BEVs will be at least as hard!

Maybe I'm a pessimist, but I just don't see 1,000 mile range in cars. As people begin to understand EVs better, people will stop pushing for longer and longer range. As energy density in batteries increases, packs will get smaller and lighter, giving more range through efficiency gains. How much faster could a mod S accelerate or how much further could it go on a charge if the battery pack with the same energy content was half the weight?

"I just don't see 1,000 mile range in cars."
I concur for Bluestar and beyond.

I expect we *might* see new gen (post-Bluestar) batteries in old gen (Whitestar) cars that hit 1,000 mi range. That's only if they (or someone) decides to offer them though.

People have historically done all kinds of interesting upgrades to the insides of old vehicle shells.

@brianman,
I totally agree with you. I just don't expect a car manufacturer to offer anything like 1,000 mile range as a factory direct model. Much more demand for a lower price than excessive range.

As a custom 3rd party upgrade, replacement battery pack with 3x energy density cells with some moderate reprogramming of the energy management unit is totally possible. There are always a few people out there who would buy it.

"As a custom 3rd party upgrade, replacement battery pack with 3x energy density cells with some moderate reprogramming of the energy management unit is totally possible. There are always a few people out there who would buy it."

If Tesla offered it (preferably with a warranty extension) in 2020, I would likely consider it.

I don't expect that Tesla would bother, way too small a market. I guess that means you and I are probably not among the "few people out there who would buy it."

I'd definitely consider a 600 mile battery pack. Not sure about a 1,000 mile pack, though, unless additional price and weight over the 600 mile version is negligible.

I believe at some point in not too far future you get 1000 mile battery pack with nearly same price as 500 mile battery pack because constructing a pack costs a lot more than what you put inside it.

No doubt many of you already saw the report that IBM is already developing a 500 Mile lithium battery prototype

http://www.greencarreports.com/news/1071654_500-mile-electric-cars-new-l...

Maybe 1000 miles is a bit optimistic, but at what battery range do you only need overnight chargers? Do people genuinely drive more than 500 to 600 miles a day in a road trip? This isn't just a hypothetical question because in practice you would place overnight chargers in far different places than standard roadside chargers. The big push would be to put these in hotels. If you were visiting families, you would just use their drier plug, and none of these would have to be particularly fast. Standard 240 volt outlets would do.

@Timo
"I believe at some point in not too far future you get 1000 mile battery pack with nearly same price as 500 mile battery pack because constructing a pack costs a lot more than what you put inside it."

1000 mile pack. I don't see the point. I'd much rather have a 500 mile pack that weighed half as much or even better, a 350 mile pack that weighed a third of the 1000 mile pack. More energy efficient, since I don't have to carry the extra battery weight.

Looking at the driving I've done over 40 years behind the wheel, a 300 mile pack with convenient level 2 charging would easily cover the vast majority of driving trips I've ever made in a car.

Exceptions:
1) 1300 miles in just over 24 hours (2 drivers) [once]
2) 550 miles to grandma's house with young children [maybe 100 times when you count the return trips]
3) 1700 miles in 3 days taking student back to college [4-5] (Not usually in such a rush on the reverse trip)
4) 400 miles in 1 day making a quick trip with another student to college, now where she lives and works, too.[6-8]

This last one is likely to happen again. It's fairly close if I make a 1-hour meal stop with L2 charging each direction. Usually in these cases, I do a few extra bits of local driving and don't really have a chance to recharge at the destination.

Even with quick charging along the route, I don't think #1 is really practical. It was insane, even in a dinosaur burner.
The rest are spread on a range between possible and convenient, with appropriate access to quick charging.

Now, assume I had the 1000 mile battery. Exceptions 2-4 become easy, with overnight charging. Exception 1 still needs a quick charger someplace in the middle. So over a lifetime of driving a 1000 mile battery would make a difference, but so rarely, I don't see how it would be worth the cost.

So the first point I took so long to get to: With good availability of quick charging, a 300 mile battery could cover nearly every driving situation I ever have been in. And Level 2 chargers at convenient stopping points along major roads would make the vast majority of realistic drives possible.

@Timo: "constructing a pack costs a lot more than what you put inside it."

Assuming you are right, and I think you are; Efficiency and automation gains in construction may be where the quickest price decreases for large battery packs will come from.

"a 350 mile pack that weighed a third of the 1000 mile pack"

Remember that reducing the weight of the battery pack raises the center of gravity of the car. It might change the driving (safety?) characteristics. Hopefully one wouldn't start putting lead in the bottom of the car to make up for lost weight.

I'd prefer well over 500 miles range. It just takes away that last bit of range planning so that one could drive for 10 hours in a day, get to a hotel with charging facilities and never have to eat at Cracker Barrel or fight for the last fast charger along the way.

At least two to four times a year (at least twice in each direction) I and my wife do 750 miles in one day. However, that's along a route that is unlikely to have superchargers on it.


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