Supercharger Anxiety

Supercharger Anxiety

We are all familiar with the term 'Range Anxiety'. Tesla has solved this with the superchargers, but has created a related anxiety: 'Supercharger Anxiety'. This anxiety appears to arise from three concerns: 1) Will all the supercharger stalls be occupied when I arrive, either by other cars charging or ICEd; 2) Will only a single spot be open and therefore I will have to split the charge and thus prolong my stopover and 3) Will the supercharger be functional. I have experienced all three. Last summer, multiple stalls at the Tejon Ranch supercharger were down when I arrived (another thread today indicates this has happened again). This week, I drove to Vegas from Southern California via the Barstow supercharger. I experienced anxiety about all spots being occupied and/or only a single spot being open. Both turned out to be true on the outbound and inbound trips. While this does not bother me, it is a major problem for my wife and kids. This is the crowd Tesla needs to make happy to get widespread adoption of BEV.

I think Tesla is working to fix 'Supercharge Anxiety' with more supercharges and more stalls per site (this approach has appeared to work at Gilroy). However, I would have preferred that they had first focused on improving the high-use supercharges like Barstow before making a cross-country route that very few will use.

mdemetri | April 22, 2014

tes-s - I agree with you, high population regions with high MS sales (like MA and Toronto) should be a priority. That is my point all along: the places with the most customers should be prioritized, or at the very least done simultaneously with the build out of cross-country SC in low population areas.

WRT to level 2 charging, I have done this many times in California despite the superchargers. But there is a big difference. When I have travelled outside the supercharger network, I did so in the full knowledge that I will have to use slow charging. This is very different when expecting quick and fast charging when planning a trip using superchargers. To compare these two is like comparing apples and oranges. One is range anxiety, the other is Supercharger anxiety. The former is done with expectations of slow charging (and if not acceptable, then taking the ICE) while the other has expectations of fast charging. Both are real anxieties and equally need to be addressed by Tesla.

Brian H | April 23, 2014

There's a bit of a chicken-and-egg problem; Elon has said they're building out fastest where the most MSes are sold. Which promotes more sales, which promotes more SCs, etc. Positive feedback. The flip is negative feedback: few MSes sold, few SCs, fewer sold, etc.

So of course they compromise some on both ends.

jchangyy | April 23, 2014

@Thomas...I also do Northern-Southern Cali trips often and I have started to take my ICE, just so that I can save extra hours of waiting to charge. It's a personal preference on my part to save time. just not worth my time at this time.

Rocky_H | April 23, 2014

@mdemetri makes a good point. The situation I mentioned about RV park charging is at least known, expected, and consistent. It sucks, but it's predictable. While I could say that you could try to leave a little earlier to account for some possible waiting, you never really know how much time it would take, and that does have its own planning problems.

kenj | April 23, 2014


I was at the Greenwich, CT N charger Easter Sunday. I was the only one there for most of the time I was there. One other MS.

The Greenwich, SB was iced and the spots are the furthest from the door -- there simply was not enough spaces -- ICEd with an explanation?

I too have been at Newark, DE -- not a like spot to be ICEd -- doesn't look like there are any spaces at all. Only one other MS charging.

rdalcanto | April 23, 2014

The OP has a valid point. If I was going to take a trip, and I thought I might be waiting 2 hours to charge when it was supposed to take 30 minutes, I would definitely take an ICE instead. In other words, crowded superchargers that make it impractical to take the EV, are no different than no superchargers at all. Either way, I'm not taking a chance and I'm taking the ICE.

Mark K | April 23, 2014

Mdemetri - thanks for this productive thread.

SC anxiety is largely the result of one key dimension of EV operation - charge rate.

You can imagine an axiom similar to Moore's Law for silicon. (Musk's Law?) for EV charging:

"Charger congestion is inversely proportional to the square of charge rate."

In other words, for a given population of EVs, the probability of contention drops by a factor of 4 with each doubling of charge rate.

Charge rate improvement is technically very challenging, but Tesla has already nearly doubled it, and they won't stop improving it.

This is useful to ponder since it actually has a much larger impact than simply the number of stalls.

3X more stalls ==> 1/3 congestion ==> Normalized probability of contention drops to 33%

3X faster charge rate ==> 1/9 congestion ==> Normalized probability of contention drops to 11%

That's dramatic. It also qualitatively improves the EV experience, since your stop time gets much shorter.

What's so cool about this is that it's a dimension driven by almost entirely by technology rather than capital, or brute force execution.

Very smart technology is where Tesla shines brightest.

I'd say the future looks bright.

justineet | April 24, 2014

You see those little critters up there in the above link. Place them in your frunk and connect the wheel to an alternator with a plug attachment to your charging port. You will never have to worry about Supercharger or any charging thereafter..never, ever....:)

gdubcobra1 | April 24, 2014

Really? We all paid the same amount for the uses of SC. Some of us have used many and some of us have used none. The have used group, sound like spoiled brats: give me more, give me more and me,me,me and always me first. Here's my idea, if the need is greater in your area, then you guys should pay more.

tes-s | April 24, 2014

@mark - agree. Telsa could replace the 90kW superchargers with 180kW, doubling the capacity without using more parking spaces.

Thomas N. | April 24, 2014



Brian H | April 24, 2014

Contention produces uncertainty.

NKYTA | April 24, 2014

Simple solution, travel off-peak. I waited once at an SC, the old Gilroy four pack.
If you can't travel off-peak, get a better job. ;-p

SCCRENDO | April 24, 2014

@NKYTA Great advice except not always practical. Some of us work for a living and don't have the flexibility. I bought my car as a means of transport with my occupation where I may occasionally need to supercharge and also for leisure. Although we all recognize a certain inconvenience relative to gasoline, superchargers are not meant to be a chore.

hamer | April 24, 2014

Others have said this before: By buying this car now, we are early adopters of a new technology. This is comparable to buying a new ICE in 1905 (or perhaps earlier). There were not gas stations on every corner. If you wanted to drive you had to plan where you'd buy gas. When you got there they might have been out of gas and there was not another gas station across the street.

Much as I want to see more superchargers more places faster (hey, I'd 63 years old and if I have to wait 20 years I probably won't be here), they are building them out incredibly fast: one year ago there were maybe 6 on the west coast, 1 on the east coast, and none anywhere else. I don't know why they're not completely transparent about it. I don't see how it could hurt them to tell us every time they've applied for a permit, bought some land, least parking lot space, started designing a supercharger, started building one, etc. The more we knew the more we might be able to help push politicians to get up off their duffs and help.

NKYTA | April 24, 2014

@SCCRENDO, yeah that was tongue-in-cheek for the most part. But I do plan my travel around busy SC days (Friday aft/eve and Sunday aft/eve). If I'm going away for a weekend, I'll try to take Monday off so I can travel easily.

Brian H | April 24, 2014

TM learned the hard way that they get the bejesus harassed out of them if they run into delays on promised SC installations, so they now say nothing very detailed until they're "100% certain".