Solar Proportional Charging

Power Sensor
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I have just started using E7-T2S charger at my house and just getting the hang of it. We have a 6.5 kW solar array and no battery so want to optimise this. It seems that there is no option to set up proportional solar charging via app or the web link? As you can see from the link i am dragging power from the grid and panels while charging car. There was discussion earlier in the year about solar proportional charging coming soon?

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Hi Matt. Thanks for your question and reference.

Yes, we currently do have solar export diversion available with our EV home charging units. This relies on a power sensor that is installed along with the charger.

We implemented this feature only recently, so we don’t have an interface on the app yet. However, if you email support@evnex.com with your name and charger serial number, they can confirm you have the power sensor installed and help set up your charger for solar export diversion on our end.

Here’s a reference to how the solar charging feature operates: Solar EV Charging

Let me know if I can help with anything else!

3

Hi Justin

I had the cable to my power board installed at Evnex install time but we were waiting for details on the sensor. I assume it requires a CT (or is it a two wire modbus?). In the meantime I have my own OCPP server set up and use Home Assistant to calculate power to send to the Evnex every minute. It also has a rule to turn on the charger from 11pm till 7am, so that if there is not enough solar during the day the car still gets charged at night with off-peak rates. How do you manage this?

Please provide details on the sensor as it will make my life easier.

Simon
charger1

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1 Like
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Hi Simon thanks for reaching out.

Reviewing your previous messages from this year it appears you moved your Evnex charger onto your own OCPP backend. Unfortunately, we cannot support the power sensor unless your charger is connected to our own network as we use proprietary messages to communicate between the charger and power sensor.

A few options I can suggest would be 1) Re-connect your charger with Evnex’x network and we will send you a power sensor at cost. 2) Continue to use the charger on your own system and configure the charger behavior with your own software.

Please reach out to the team at sales@evnex.com if interested in the power sensor option.

5

I have been using my own sensor and an automation in Home Assistant that uses the OCPP module to talk directly to the Evnex charger. The automation calculates the excess exported power to the grid and creates a plus or minus delta on the present current export to the car. It also has cut off limits so will not permit charging unless there is at least 6 amps available.

    pos_delta_pv:
      unit_of_measurement: Amps
      value_template: >
        {% if states('sensor.grid_feed_in')|int > 400 %} 
          {% set temp = ((states('sensor.grid_feed_in')|int ) / (states('sensor.meter_voltage_a')|int)) %}
          {{ temp | int }}
        {% else %}
          0
        {% endif %}
    neg_delta_pv:
      unit_of_measurement: Amps
      value_template: >
        {% if states('sensor.grid_consumption')|int > 240 %} 
          {% set temp = ((states('sensor.grid_consumption')|int ) / (states('sensor.meter_voltage_a')|int)) %}
          {{ temp | int }}
        {% else %}
          0
        {% endif %}
    pv_to_car:
      friendly_name: "PV to car"
      unit_of_measurement: Amps
      value_template: >
        {% if states('sensor.evnex_power_active_import')%}
          {% set temp = states('sensor.car_current') | int + states('sensor.pos_delta_pv')|int - states('sensor.neg_delta_pv')|int %}
          {% if temp > 32 %}
            32
          {% elif temp < 6 %}
            0
          {% else %}
            {{ temp | int }}
          {% endif %}
        {% else %}
          {{ states('number.evnex_maximum_current') | int }}
        {% endif %}

This then drives an update to the Even sent once per minute. The current limiter is shown in a typical days charging below.

Evnex1

Note that it charged during the day and respected the limit. My Outlander PHEV will max out at about 14 amps. I have also set a 11pm to 7am unlimited use as this is my off-peak tariff and tops up anything that the solar could not provide. You can see a cloud blocking solar at 2pm and the reaction of the current limiter on EVNEX charging

6

Looks to be doing the job well!