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 and becoming a Supporting Member. For more info: Support TMC
Start a Discussionhttps://teslamotorsclub.com/tmc/tags/

Daisy Chaining Wall Connector

Discussion in 'Charging Standards and Infrastructure' started by Driver Dave, Dec 15, 2016.

  1. Driver Dave

    Driver Dave Member

    Joined:
    Oct 10, 2016
    Messages:
    211
    Location:
    Boston, MA
    (Oops, posted in wrong group, please ignore)

    I had one Wall Connector that did:

    35 mi/hr 230V 48/80A

    I just added another one and daisy chained and now they charge at:

    13 mi/hr 230V 20/20A Model S 75D
    4 mi/hr 230V 20/20A Model X 90D

    The batteries are super cold right now (they where outside while electrician was working) so mi/hr may be low because of that.

    But in general, does the 20/20A look correct? Should be say 24/40A?
     
  2. araxara

    araxara S-P85#3,218 X-90D#3,299

    Joined:
    May 11, 2012
    Messages:
    755
    Location:
    Tucson, AZ
    The HPWCs will advertise their available charging amperage and based on the cars plugged in and what is available, they may not advertise a combined amperage of 80A. I have a similar issue with my Model S and Model X. Model S can charge at 72A and Model S can charge 80A. Today I plugged in the Model X (while the Model S was plugged in and had completed it's charge the previous night). The Model X Read 6/6A for a long time. I decided to press the reset button on the HPWC attached to the Model S. The current jumped to 24/72A and started to climb from there.

    I don't know what algorithm the chargers use, or if they communicate with the car also, but I find it annoying many times. Sometimes, I need to quickly charge one of the cars to 100% for a trip. I used to start charging from my iPhone app, but now I will start the charge from the app and have to walk into the garage and unplug the other car, so that the charging car can get the full current.

    Also, for your example above, 20/20A would be OK, if the other car read something like 60/60A (the 2 bottom numbers [20A+60A] will always add up to 80A or less).
     
  3. Rocky_H

    Rocky_H Active Member

    Joined:
    Feb 19, 2015
    Messages:
    1,428
    Location:
    Boise, ID
    This was answered in the other section. Master HPWC did not have the switch set correctly.
     
  4. Driver Dave

    Driver Dave Member

    Joined:
    Oct 10, 2016
    Messages:
    211
    Location:
    Boston, MA
    When they weren't daisy changed I got 35 mi/hr charge on a single.

    Now connected, but the other one not plugged in, I only get 30 mi/hr?

    Have you see this?
     
  5. araxara

    araxara S-P85#3,218 X-90D#3,299

    Joined:
    May 11, 2012
    Messages:
    755
    Location:
    Tucson, AZ
    For me, when only one is plugged in, I get the full current available (80A) as displayed on the screen. The corresponding car (Model X/Model S) will also charge at the full current (72A/80A). Of course, near the top of the battery level it will begin to taper off, but that's what it's suppose to do.

    In my setup, I have separate breakers for each HPWC, so I can actually power off each charger individually. But in order to get the full charge current, I only need to unplug one of the cars. I can also hold in the reset button on one of the chargers and the other charger will deliver full current, but after a while, the idle car's HPWC will start to request some current (about 6A most of the time) and the one charging will drop a bit (unless it's charging the Model X, since it only takes 72A).

    In your case, I would compare the current that the charger says is available. Using the mi/hr measurement is not accurate, because in the master/slave HPWC configuration, the current usually starts of a lower and the charger will increase the current available after time. This has the effect of lowering the mi/hr number, since it's not an instantaneous number but a charging average.
     

Share This Page