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Did a 2700+ mile road trip a few weeks ago, and a LOT of DC charging. On my way back to LA, I had the pleasure of getting an informal tour of an Electrify America charging station at WalMart in some hot, awful town near Fresno (where somebody stole my wife's $5 hat that was on top of the car, WHILE we were standing there)

My experience with EA on the whole 3 week trip was just short of garbage. I didn't have a lot of faith, and when I showed up at this station, it took 3 tries to find a charger that was putting out the rated current. A lot were offline too, which was typical.

So as I'm sitting, trying to feed my kids out of the back of the car in 105F and direct sun, one of the kids noticed that the door to the barrier around the electrical equipment was unlocked. As I was having trouble with the chargers and was on the phone with EA, I mentioned this to them. And within 20 minutes a tech had been dispatched. We'll call him Larry, because I'm not sure he was allowed to let me be this nosy.

Larry was a great dude. As I understand, EA jobs out to local electrical contractors to work on their stations, and there are a few in distinct regions throughout the state. He showed up and I started asking questions. The good news is, that according to Larry, 50% of the time all he has to do is come and reset the chargers. I asked him why they couldn't do this from the back office and he just rolled his eyes and laughed. But he did say that most of the issues are software, and they're updating machines a lot. Much of the rest of the time it's replacement of vandalized screens and other equipment, and a few boards being replaced. They're also apparently replacing the low voltage power supplies in the "dispensers" for more reliable units. Dispenser is the terminology they use for the actual boxes that have the screens and plugs on them.

The system:

EA Dispensers have a point of sale system in them, a computer, credit card reader, and a modem of some sort to connect to their servers. The NYAK credit card readers were on Larry's naughty list, and I got that feeling from the phone reps too, but he had faith that something would be worked out. The dispenser also had the liquid cooling system, a reservoir for the circulating oil, and the pump. That's the sound you hear. There are also some small fuses and a fiber optic transceiver for communicating with the power supply. And of course, the enormously fat connections for the actual DC current.
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Have a look at those DC cables. Compare them to the ethernet jack. These wires are ENORMOUS. These run full power without the benefit of liquid cooling, hence the heft.

Sessions work like this: Roll up and start a charge. The dispenser then sends a command back to the power supplies in the vault, over the fiber optic connection (not hard to see why they chose fiber in an environment like this) and then the power supplies turn on the DC. No conversion takes place in the dispenser, and they're electrically dead until a session is active.

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These hogs are the actual power supply / chargers themselves. There's one for each and every plug at the station, and some plugs have TWO units assigned to them. In other words, if the first plug at a dispenser isn't working, try the other plug at the same dispenser, because it's connected to an entirely different power supply. Regarding these power supplies, I confirmed with Larry, but didn't see with my own eyes, that these are modular systems, and have a bunch of modular power supplies in them. If some of them are offline, it will still deliver power, but not full power. It's a graceful way to fail, but I'd like to know BEFORE I plug in to a station how bad off it is, especially because they bill by the minute (which I understand is changing)

Other fun stuff in these vaults is a set of big inverters and a couple of Tesla Powerpacks, along with your standard fare switchgear. Everything here seems to be running on 480V 3 phase, but Larry implied that there's some high voltage in here too. What's high voltage depends on who you ask.

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So there you have it, some of the guts of an EA station, and it sounds like most of their woes are software related...and credit card reader related.

Now as far as these vaults go, I'm guessing they're going to have to do some modifications to them at some point, since I guess people like to shack up and hang out in them, set up camp, or just start pulling levers and peeing on things. Yep. They just climb over, and open the door up from the inside and take up residence. So they'll probably chainlink over the top of them at some point, but until then, I hear that the contractors just WORK AROUND the people that are in there.
 

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This sort of post isn’t normally my thing, but I found this report so interesting. Thanks for sharing!
 
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