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How the new 7-Eleven DC Fast Chargers work

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wycolo

Active Member
May 16, 2012
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WA & WY
Announced in June 2021 the new 250 location chain of 7-Eleven SuperChargers will operate with unique technology that Tesla owners might find intriguing. This was explained in a video I watched but have lost since then and cannot find in searches. Anyway these are what I call "one-shot superchargers" since they store up a relatively slow charge using the existing electric wiring of a 7-Eleven store into *batteries* similar to a PowerWall. Then when an EV arrives wanting a charge the EV plugs its DCFC or Chademo or (gasp) maybe even a Tesla plug into the 7-Eleven stantion/kiosk charging unit and charging takes place rapidly. All this without the store having to install high power transformers and get special construction permits etc since it only uses a 40 amp 240 volt circuit that could be easily hooked into the existing wiring of the store.

This is an excellent plan for out of the way locations that might only be visited a few times a day. You could push a button and the screen could show how full the battery is and how long before it could deliver a fast supercharge to your EV. Some of these stations already exist, maybe in California, so please someone check this out.
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Neat idea, and certainly better than no/L2 charging only, but what happens when you get there and you are the second EV to visit in the past several hours. Its almost like you need to plan for it to be an L2 charger and be overjoyed when it turns out to be 'fast'. I know if I were on a roadtrip(think some national travel holiday like thanksgiving) it would absolutely suck to visit 7-11 after 7-11 searching in vain for a charged unit.

It would be somewhat better if there were online-interrogation of charge level.
 
Are you talking about the Freewire DC fast chargers, or something similar? I hadn't heard anything about a partnership between them and 7-Eleven, but that proves nothing. In any event, my understanding of the Freewire chargers specifically is that they have 160 kWh of battery capacity, which is likely to be enough to handle at least two or three DC fast charging sessions -- and the unit continues to receive power (at a rate of 27 kW) while the car is charging, so it'd be more than that, back-to-back, before the unit's battery was depleted.

I've seen the Freewire units pitched on YouTube, and it seems to me that they fill a niche, but a limited one. One or two of these units could go at a convenience store or whatever, while not requiring major upgrades to the store's current energy supply, whereas adding a non-battery-backed DC fast charger might require upgrades. This is what the company is currently emphasizing. The trouble is that when you scale it up, that advantage goes away, or at best it morphs into a less compelling advantage. Try a bank of ten of the units, and the maximum draw goes up to 270 kW, and even more for bigger installations. Moving beyond one property, if you've got a bunch of restaurants or convenience stores with these units in an area (say, near a highway exit), you'd still be increasing the energy needs for that small area by megawatts, which could well require grid upgrades. So would conventional non-battery-backed DC fast chargers, of course. On this scale, the big advantage of the Freewire units is that they'd tend to make the energy draw more consistent over time, with less extreme peaks in demand. I expect that utilities would prefer this, but I don't know how the economics of it will work out in the long term -- it's the cost of batteries vs. demand charges, ultimately.

Of course, bigger installations sometimes use batteries that are separate from the DC fast chargers themselves, which provides the same advantages, at least in terms of grid demand. (The Freewire units are more compact, which could be an issue on a cramped property.)
 
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Yes it was the Freewire DCFC video on YouTube, thank you. 160 kwh would be twice the size of a ModelS battery so perhaps would need to be housed in a separate cabinet rather than the in the kiosk itself. Still it would be a quick & easy install compared to a real Tesla SuC. But scaling up beyond ~4 kiosks seems to be beyond sensible for 7-Eleven stores IMHO. The customer base would be either lost or confused EV tourists hard up for a charge or local EVers who lack their own garage/yard charger. Just as we tend to think of EVGO/EVAmerica as being located at Walmarts it would be nice to know that 7_11s generally would have a FreeWire Charger available.
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I like the idea and have argued for those in another thread here. After just having to deal with that stupid 250+ mile gap between Winnemucca and Boise again yesterday, this reminds me how nice that would be to have 100kW+ charging speed for the small number of cars that go through there.
 
How do you manage that leg? You could probably go real slow whenever traffic permits after supercharging to 95%. If it is an up-n-down route you can coast to Boise and save a good bit. But you've done it before which is the hard part. My nut to crack is Rock Springs to Pocatello, 240+ miles but now with some extra 20+ miles in the new battery I just might give it a try next week - wish me luck.

I'd hate to try to work out the economics of sponsoring a FreeWire install, much less a 240v50A stantion at a motel or a tiny rv yard, but if you can add a route leg to a regular commute you should try something since winter is approaching, not to mention the possibility of headwinds.
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How do you manage that leg? You could probably go real slow whenever traffic permits after supercharging to 95%. If it is an up-n-down route you can coast to Boise and save a good bit. But you've done it before which is the hard part.
That route has an interesting history, and I've done it a couple of times, and I have heard from others who have done it.

Back before Boise had any Superchargers, I talked with a guy from Reno while he was charging at my house from my 14-50 being listed on Plugshare. (hard to believe that was the fastest charging in the city back then) He had done the entire trip Northward (downhill) very carefully in his P85, with no charging at all and got in with 9 rated miles left! Yeesh. Back then, the only charging option was an RV park in Jordan Valley that he didn't use.

Later, I did that route going South (uphill). The Say When casino in McDermitt had high amp wall connector available. So I drove slowly and carefully there, and took a decent lunch stop at their cafe for just a little over an hour (my car can only take 40A) and got a coffee to go, and then slowly on to Winnemucca.

After that point is when Greenlots built the fast charging stations with CCS and CHAdeMO in McDermitt and Orovada. Orovada is so close to Winnemucca it's not very useful, because it's still about 217 miles on the upper part. So I had my CHAdeMO adapter this time and used that in McDermitt. Aside from the hassle of 6 or 7 tries with app and RFID card and touchscreen/credit card and back to the app to finally get the station to activate, the charging was pretty quick and not too bad then. So CHAdeMO is fast enough to make that OK, but not all Tesla owners have that adapter, and it's much more cumbersome and unreliable to be able to get the station to work.

Say When doesn't have the wall connectors now either, but the RV park in Jordan Valley is still open and kind to charging, so that's the only level 2 available on that route now.