https://www.tesla.com/support/supercharger-idle-fee says that the idle fee will be charged if at least 50% of spots are full "once the charge session is complete". This doesn't specify whether the fee/no fee determination is based solely on the instant that charging is complete, or on a minute-by-minute basis thereafter. Does anyone have any data that would clarify this point?
Grr. Information owners and drivers do not have.
Today, coming from almost the swamps up by Hwy 4, I became the person they are waiting for at the SuperCharger for my second time. It's not a very interesting story, and yet I still seem to have found a way to ramble on about it. Not much to see here unless you need to pass time.
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Tried to go to DMV. Turns out, it was one of the DMV's that the people don't demand better service, so I left in a jiffy. Went to a Nissan and paid to use their EVGO Chademo. It was slow, at around 30kW (4900Wh/(10minutes/60minutes/1hour) to get 19% - 26%), but it gave me breathing room to make it to Dublin, a congested SuperCharger. As soon as I arrived, the SC kW made the Chademo seem good; to go from 12% to 55% averaged around 52kW (27900wH/(32minutes/60minutes/1hour)). I should have stayed at the Chademo longer. I knew it would be a bit of time before I had enough charge (the Tesla map navigation planner told me as much), so I took off on foot and asked the store staff where food was, got free coffee, expressed how that's a free perk in its august (since Model 3 is coming), and set out to the gun store snack counter and then Safeway for what turned out to be some of the best premade sandwiches at any Safeway ever (from my point of view).
I noticed how walking during charge events is a new way to get exercise, and walked back to my car. There was a line (of Teslas waiting to SuperCharge, two deep).
I decided to get to the point at which I could make it home at around 10%, so sat in my car SuperCharging for another 5 minutes with a growing line of people waiting to charge behind me. When I thought I had enough buffer to reach home at 10%, I unplugged at a state of charge of 55% at Dublin, backed out immediately (didn't even adjust my sitting position in my car or anything) so as to give room to the next person in line, and left. As I drove by, I noticed the line had grown to four. My planning is getting much better: I arrived home with 12%.
I think I balanced my buffer space with the waiting needs of the people behind me quite well. Too bad there wasn't a Chademo in my one stop halfway between Dublin and home, otherwise, I would have been able to leave 5 minutes earlier from the SuperCharger and just fill whatever buffer I needed at the Chademo. Even better: I could have eaten less, and left the SuperCharger after only 15 or so minutes, rather than the full 32 minutes I ended up staying. I could have added the buffer space to the halfway point from the SC to the second homebound leg once I got to the midway charging point, and saved time charging. Instead, I had to build a bigger buffer for a longer throw all the way from the SC to home AND the actual energy needed to make it all the way there.
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Did you notice something there? The behavior modification going on right now in my mind in California is one of desiring, preferring, and wanting to use Chademo over SuperChargers. I have wondered more than once if this was part of Tesla's plan, now that there's a huge EVGO network of Fast DC chargers sitting all over the state relatively underutilized.