What's the Ideal Distance Between Superchargers?

[NoMoGas]

If you are navigating to a Supercharger, the Nav page should automatically provide Supercharger status, number of stalls in use, number vacant, any blockage history in the last few hours, etc. If there are problems, or a high blocking rate, the Nav App should suggest alternative Supercharger sites; a great method of load spreading and providing a safety net for Supercharger failures or problems. Just a few rants from a retired engineer who used to design highly reliable, high availability systems. :wink:

i was just thinking the exact same thing

 

[daxz]

I see the answer depends on 3 main things:

1. Car consumption - how much wattage per mile the car needs (accounting for weather, terrain, battery size, speed, congestion)
2. Time to get off intended path to get to and hook up to the charger
3. Which battery charge rate (60kWh, 85kWh Atype, 85kWh Btype)

based on my estimations of the above
95-110 miles for an 85kWh B type battery car using .35 - .4 kWh/mile and taking 7.5 minutes to go off course and hook up
65-90 miles for an 60kWh battery with same usage/time

85-B would charge 18 minutes and 60kWh would need to charge for 30 minutes each stop for ideal travel time.


Other minor assumptions that would be needed to take into account.
4. Range anxiety (buffer needed) ( best case is 5-60% state of charge)
5. Time needed for other things people do during stops (getting food/eating/shopping/other stuff...) - this will be variable based on starting point and what is close to SC. (may take over 30 minutes to go somewhere and get back)
6. ratio of 60kWh cars vs 85A-type vs 85B type

looking at time it takes for charging to travel 500 miles:

The 85kWh+ battery size looks even more desirable for long distance driving.
So based on this - I see distances of ~95 miles between chargers as ideal.

[edit - added 85kWh Type A curve]

 

[Cottonwood]

See my posts at Tesla Supercharger network - Page 346 and Tesla Supercharger network - Page 347 for my proposed rule of thumb on maximum spacing for easy, comfortable use of Superchargers.

 

[John Luciano]

Anyone consider pay stations. Maybe $2.00 a 1/2 hour. You might get someone to stArt a franchise of charging stations and tie them into Dunkin doughnut or Starbucks. Mc Donald's. Cracker Barrel. Driving X country on $40.00 not to bad.

 

[wycolo]

Planning a road trip Cheyenne WY to Macedonia OH pulling a small trailer so I was concerned about the 200 mile stretch between Mauston WI and Highland Park IL. Not a problem for an S85 but with the trailer my car is now essentially an S60 until proven otherwise. As luck would have it there are now TWO SuperChargers: Rockford and Aurora that better rationalize the cross country route. Highland Park SC is at the service shop and is way out of the way. Still there is a 200 mile stretch unless you stop at *both* SCs which brings it down under 140 miles per charge. Way to go Tesla Motors!!:biggrin:
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[EVFest]

Anyone consider pay stations. Maybe $2.00 a 1/2 hour. You might get someone to start a franchise of charging stations and tie them into Dunkin' doughnut or Starbucks. McDonald's. Cracker Barrel. Driving X country on $40.00 not to bad.

Funny! $40 is what it cost me to Drive from San Antonio, TX to Toronto, ON - but - that was when Gas was a Buck a Gallon = 40 Gallons for the trip (~1988)! And - It was in a Chevy Sprint (Geo Metro) - not a mid or full size car, like a Model S!

Go Transit, in Ontario, Charges $2.50 a use (but only offers L2 Stations at 30 amps top at present), similar to The Quebec Electric Circuit! Quebec at least offers DCQC's in their network!

 

[jerry33]

Anyone consider pay stations. Maybe $2.00 a 1/2 hour. You might get someone to stArt a franchise of charging stations and tie them into Dunkin doughnut or Starbucks. Mc Donald's. Cracker Barrel. Driving X country on $40.00 not to bad.

$50,000 per charging station / ($2 * 48 half hours) ~= 520 days Assuming that it's charging 100% of the time and that your electricity is free because it's coming from your solar panels and storage battery that you've already paid for. A more likely scenario is that each stall will have a 1.5 hour use per day (and even that might be high) $50,000 / ($2 * 3 half hours per day) ~= 8,300 days or 22 years.

 

[neroden]

Just looked at this. I had come up with 90-95 mile distance between chargers. 260 miles of charge (don't want to use that last 5 miles, too nervewracking), range reduced to 70% during the worst of winter, want to be able to handle a single site failure.

Daxc came up with ~95 miles based on different principles.

Getting the same number from two different sets of principles, I think it's correct.

 

[Robert.Boston]

Just looked at this. I had come up with 90-95 mile distance between chargers. 260 miles of charge (don't want to use that last 5 miles, too nervewracking), range reduced to 70% during the worst of winter, want to be able to handle a single site failure.

Daxc came up with ~95 miles based on different principles.

Getting the same number from two different sets of principles, I think it's correct.

Given the sharp tapering on SuperChargers, plus battery degradation, I'd start this calculation with 225 miles of range in the battery, which puts optimal spacing at 70-75 miles. Given that Tesla is currently installing SCs at about 130-140 mile spacing, I think what we'll see is new sites in between, so in practice spacing will be 60-70 miles along major routes.

- - - Updated - - -

Anyone consider pay stations. Maybe $2.00 a 1/2 hour. You might get someone to stArt a franchise of charging stations and tie them into Dunkin doughnut or Starbucks. Mc Donald's. Cracker Barrel. Driving X country on $40.00 not to bad.

$50,000 per charging station / ($2 * 48 half hours) ~= 520 days Assuming that it's charging 100% of the time and that your electricity is free because it's coming from your solar panels and storage battery that you've already paid for. A more likely scenario is that each stall will have a 1.5 hour use per day (and even that might be high) $50,000 / ($2 * 3 half hours per day) ~= 8,300 days or 22 years.

I agree with Jerry re capital recovery. Three users every day is about 1,000 charges annually. To earn a 10% return (which is pretty low), you'd need $5 in capital recovery costs per charge.
The power is never free, though: either the station owner has to pay the utility or forego payment for solar power it could have sold. That adds at least $5 per charge (50 kWh at $0.10/kWh). So, I think we're looking at $10 per use for a private supercharger to be approximately break-even