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Slow Charging on L2 charger

Discussion in 'Prime Plug-in Charging' started by m8547, Dec 13, 2018.

  1. m8547

    m8547 Senior Member

    Joined:
    Aug 8, 2018
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    Location:
    Colorado
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    There is a Chargepont charger at work, but lately it often charges slower than full speed.

    It is a 6.6KW charger with shared power, so 3.3KW per car if there are two. No problem there. And sometimes it limits power for other reasons and alerts me, something like "charging at a limited rate" and "Full power restored". But I rarely get those alerts.

    But lately when I plug in it charges at 3.21-3.24 KW for a few minutes, then goes down to 2.2KW, 1.8, or even 1.2KW for most of the time, then goes back to 3.2 KW for a few minutes before tapering off as charging finishes.

    Today it's 28 degrees and it went to 2.2KW after 10 minutes, so maybe the battery is cold. The display showed 2h 10m to charge, but it will take longer than that at 2.2KW. If it was just the battery being cold, the car should have known ahead of time that it would take longer. A couple days ago it was ~50 degrees and there was no other vehicle using the charger, but it went to 1.2KW. I walked over and unplugged it and started a new charging session, and it went to 3.2KW (but I had to leave so I didn't wait to see how long it would go at that power). Yesterday it charged at 3.2KW the whole time.

    Once the charging speed goes down, it rarely ever goes back to 3.2KW except for the last few minutes of charging.

    Is this a Chargepoint problem, or a problem with my car, or maybe just normal behavior for the car?
     
    #1 m8547, Dec 13, 2018
  2. LoraJ

    LoraJ Active Member

    Joined:
    Jul 4, 2009
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    Location:
    NJ
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    It could be how the ChargePoint charger is set. I am not an expert, but I think it is pretty standard that the last 20% of your charge will be at a slower rate. I honestly don't pay attention to any of this, are they charging you to charge? At my job they are free and I just plug in and get an alert that the car is drawing little power and to move it after about 2.5 - 2.75 hours.

    I use another L2 charger that is free and not ChargePoint and my car will say it has 30 mins left to charge but if I unplug it it will be close to 100%.
     
    #2 LoraJ, Jan 12, 2019
  3. m8547

    m8547 Senior Member

    Joined:
    Aug 8, 2018
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    Location:
    Colorado
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    They charge by the kWh, so might as well leave it until it's full. They put in some new 6.6kw chargers, and I haven't seen the same problem since using those, so maybe it was just something weird about the other charger.
     
    #3 m8547, Jan 12, 2019
  4. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

    Joined:
    Nov 27, 2005
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    Location:
    Roseville, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Just a note that public ChargePoint chargers are programmed to bill however the owner of the station wants: by Kwh, by time (including a variable rate, with later hours charged at a higher rate), a combination (Kwh until charging complete, then by time, to keep people from hogging the station), or just plain free.

    Billing formulas involving Kwh are not practical in some states, which have decreed that charging by Kwh makes the owner of the station into an electric utility, subject to the regulatory processes for utility companies. But billing by time is just a rental of a parking space, with the electric charging thrown in. :rolleyes:
     
    #4 CharlesH, Jan 14, 2019
    Last edited: Jan 14, 2019
    kevin.c likes this.
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