Tesla Supercharger network

[EdA]

A few supercharging comments...

1.) Regarding Boston to NY (or points further south): I never drive on Rt. 95 when going to NYC - kill me before I take the Cross Bronx Expressway again. I will take whatever route is going to be the least busy be it 84-684-Hutchinson River Pkt or the Merritt...but NEVER EVER 95. Texans, sorry to be so parochial.

2.) Let's say there's a charging station outside of "Springfield" and I happen to live a few miles from "Springfield". What's to stop me from ever charging at home and always using (clogging up) the SuperCharger? Is Tesla going to enforce some kind of limits to keep locals off of the SuperChargers? I know when I'm on my road trip, a half and hour of SuperCharging is going to be more than I want to stop.

I can see myself doing Boston<->Philly a bunch of the next N-years while my daughter is in college...

[Robert.Boston]

Good points, @EdA . I almost always use I-84/I-684 so an SC near Danbury cT would be really good. The Milford SC could be helpful visiting my daughter in New Haven. Also a good choice for New Yorkers traveling to Cape Cod.

However, given that there will be an SC in Milford, I expect that I'll detour there to top up even en route to NYC.

[Cottonwood]

However, given that there will be an SC in Milford, I expect that I'll detour there to top up even en route to NYC.

I have a friend in Newton, MA with several properties on Fire Island. The Newton, MA to Bay Shore, NY drive that he does MANY times a year was a stretch even with the 85 kWh battery. Now, with the Milford Supercharger, its a no-brainer. He is now seriously considering a Model S.

Superchargers may be what ultimately make Tesla a success.

[Larry Chanin]

The only thing unwise about charging in Range mode at a Supercharger is that the charging just slows down to a normal charge rate at the end to protect the battery. Its not unwise in terms of battery life, but it is very unwise in terms of time to charge when on a trip.

You make an excellent practical point. However, I received the following response from Tesla engineering following an inquiry that I made:

"Charging in Max Range mode regularly will indeed accelerate battery degradation. Degradation mostly occurs at the upper end of the battery when it’s at very high voltage. Range mode is there for a reason – to give you max range – and customers should feel free to use it when it makes sense. We recommend using Standard mode for most daily driving."

I agree that the Supercharger has a level of sophistication in communicating with Supercharger enabled batteries that is probably greater than conventional universal chargers. Nevertheless, beyond the practical advice that Supercharger fast charging probably ceases to be fast when fully charging in Range mode, I believe there probably is an added increment in battery degradation by Supercharging in Range mode. Put another way, if charging in Range mode degrades the battery at much lower capacities, it is not unreasonable to expect that charging at very high capacity, at higher heat loads, would probably be incrementally more damaging.

Larry

[VolkerP]

Larry,

I think the "damage" to the battery when charging beyond 90% SoC is mainly determined by charging power and cell temperature. The superchargers begin to cut back from 90kW as early as 50% SoC. When range charging above 90% SoC with a super charger, I expect the charge power to fall below 20kW, the equivalent of AC charging with twin chargers. So that should not differ from level 2 (AC) charging.

Heat load should be reduced when supercharging above 90% SoC, since Model S can redirect cooling power from the 10kW onboard chargers to the battery. Outside temperatures might play in here.

[Oyvind.H]

2.) Let's say there's a charging station outside of "Springfield" and I happen to live a few miles from "Springfield". What's to stop me from ever charging at home and always using (clogging up) the SuperCharger?

We discussed that in a norwegian EV forum recently. The conclusion was that power is so cheap noone here would detour and wait around at the Supercharger just to save a few bucks.
And even though Tesla claims supercharging will not affect the battery, I would not risk any degradation from extensive supercharger use. Saving a few dollars at the risk of accelerated degradation and wasting time hanging around a charger is a no-brainer to me.

You don`t buy a $70-90,000 car and cheap out on charging.....

[JRP3]

Put another way, if charging in Range mode degrades the battery at much lower capacities, it is not unreasonable to expect that charging at very high capacity, at higher heat loads, would probably be incrementally more damaging.

Larry

I disagree. The supercharger will have to reduce current at higher SOC's to the same range as any other charger, and the pack TMS will be keeping pack temperatures in line well before the higher SOC is reached. By the time your are into the final 10% or so of a range mode charge on a supercharger I don't think the battery will be experiencing anything different than a range mode charge from an onboard charger.

[wayno]

So, here's my speculation (posted in another thread):

Milford: the Westfield Connecticut Post Mall. Sits on I-95, ample parking, stores, dining.

Wilmington: the Christiana Mall. Sits at a critical point on I-95, just south of the NJ Turnpike split and just north of the DE-1 connection, leading down to the Delaware coast. High end mall, Apple store, same owner as the Natick Mall (home of the Tesla Boston store).
.

I couldn't agree more on the Christiana Mall location. I went over there last week to scout out locations, and came up empty handed though. Even again tonight having Dinner at the mall, I couldn't find any signs of a supercharger construction area. I also checked out the I-95 rest area in DE as the next logical location and came up empty there as well. I would imagine that in order for it to be operational within a month there would need to be some sign of construction at this point. I will keep looking though until I hear an announcement.

Thanks,
Wayne

[hcsharp]

I disagree. The supercharger will have to reduce current at higher SOC's to the same range as any other charger, and the pack TMS will be keeping pack temperatures in line well before the higher SOC is reached. By the time your are into the final 10% or so of a range mode charge on a supercharger I don't think the battery will be experiencing anything different than a range mode charge from an onboard charger.

I think you're right JRP3. Unless there's something we don't know, you can't apply much more than 4.2v to a Li-ion cell while charging it. That doesn't leave enough voltage differential to apply more charging power regardless of method. That's why it starts cutting the rate down fairly early when Supercharging.

[JRP3]

Yes you have to keep voltage below the electrolyte solvent breakdown voltage so current has to be reduced. EPhase: Battery Electrolyte Breakdown Voltage
It's like filling a bucket with a hose, when the bucket is empty you can use high pressure and not spill anything, but as it nears full you need to lower the pressure if you want to fill it all the way.