TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

St. Louis low power supercharger or gotcha on pair priority?

Discussion in 'Midwest/Great Lakes' started by Skotty, Oct 5, 2016.

  1. Skotty

    Skotty 2014 Model S P85

    Joined:
    Jun 27, 2013
    Messages:
    1,440
    Location:
    Kansas City, MO
    #1 Skotty, Oct 5, 2016
    Last edited: Oct 5, 2016
    For the St. Louis folks, I had an interesting experience yesterday while at the St. Louis supercharger. I pulled into 1B. Another car pulled into 1A shortly after me (like less than a minute after me). There was also a car on 2B. 3A was empty (note: there is no 3B at the St. Louis station). I plugged in to 1B about 20 seconds before the other person plugged into 1A.

    Based on prior discussions, the general expectation would be that my car, having been plugged in first, would get priority. However, I noticed that I was only getting about 100 amps. So I moved to 3A, where I started getting 300 amps.

    I had a friendly chat with the couple in 1A who asked why I moved. I did my best to explain the supercharger pairing thing. He said he was still learning. I told him it I was just trying to maximize charging for both of us, trying to reassure him they didn't do anything wrong. Seemed like nice folks.

    So the question is, what is up with 1A and 1B on the St. Louis superchargers? If two of you have the time some day, might be worth playing around and testing out the pairing theory there. Either 1B isn't giving full charge right now for some reason (entirely possible), or pair priority didn't work the way we generally expect it to, or less likely, maybe the pairs were mislabeled. Quite possible it was something else, but the experience did cast a little doubt on the generally accepted pairing theory; whether true or not, it kind of seemed like it was giving 1A priority over 1B, regardless of who plugged in first.

    The nice couple I talked to didn't seem the type to want to spend time running charging experiments, so I didn't look into it any deeper while I was there.

    For the Kansas City folks, the KC station isn't too far from where I live. I'd be willing to join up with someone to run tests on the KC station pairing some day; only trick is ensuring you have a low charge on that day.

    Does anyone know of anyone else who has actually tested pair theory at any stations? Any one station might not work the same as another, but real testing results would certainly be interesting regardless of which station it is. I've never heard of someone really testing it before in a scientific manner.
     
  2. Skotty

    Skotty 2014 Model S P85

    Joined:
    Jun 27, 2013
    Messages:
    1,440
    Location:
    Kansas City, MO
    Here's my general idea for pair theory testing. First, it would be nice to test multiple stations to see if they are all consistent or if there appear to be differences based on station. Ideally, pick a variety of stations, some older some newer. However, for the rest of this post, I'll just talk about testing a single station.

    Have 2 cars low on charge, car X and car Y.

    I) Test charge rate of X on 1A and 1B, and verify full charge rate on each.

    II) Test charge rate of Y on 1A and 1B, and verify full charge rate on each.

    III) With both cars in 1A and 1B, test plugging in A first, followed quickly by B. Check charge rates.

    IV) With both cars in 1A and 1B, test plugging in B first, followed quickly by A. Check charge rates.

    V) If first to plug in isn't always given the expected priority:
    a) repeat tests III and IV allowing a longer period of time before plugging in the 2nd car.
    b) repeat all tests on 2A and 2B.

    I think a procedure similar to the above would give a reasonable amount of confidence on the behavior of a particular station without taking a ridiculously long doing the tests.
     
  3. Skotty

    Skotty 2014 Model S P85

    Joined:
    Jun 27, 2013
    Messages:
    1,440
    Location:
    Kansas City, MO
    As a side note, I also met the CEO of GoSolar while I was there. Was an interesting day at the Supercharger.
     

Share This Page