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Charge EV with excess solar without Zappi

  • 17-11-2022 9:21am
    Registered Users Posts: 1,392 ✭✭✭

    OK so have 7.6Kw solar installed, 6Kw inverter, 20Kw batteries and an EV already with Easee charger installed, my EV is not at home most days so I cant really take advantage of excess solar however will be getting a second EV next year and this will be at home most days so it will be able to use excess solar.

    I could get a Zappi which would cost €999 and the Harvi stuff and another €130 and then sell the Ease charger for €400.00 - 500.00. however we have high usage here in the house where we use typically 30Kw per day not including the car so I think the most excess available for the zappi would be around 3Kw


    I could get an outdoor wifi plug where I could plug in a 10A 3 pin charger the and write a script in Home assistant to switch on the wifi plug on/off when there is excess solar .

    My script would run every 20 mins I reckon:

    1. If Excess power is 2Kw and battery capacity is greater than 40%
    2. Turn on socket

    And if those conditions are not met then turn off the socket.

    Now there is also an API available for the Easee charger that could be controlled with HA also but it seems to have issues as the availability seems to be down at times.

    So just looking for thoughts on this if anyone had them ?


  • Registered Users Posts: 1,392 ✭✭✭Big Lar

    Or Option 3.

    As the inverter is just inside the back door could I hook the 10 charger up to the backup power on the inverter and set the inverter just to use solar for backup ? Or would that draw from the grid I wonders

    Thats more of a random thought than anything else

  • Registered Users Posts: 1,012 ✭✭✭allinthehead

    These chargers are quite a bit cheaper than the Zappi and have all the same features. Wouldn't cost much after you sell on your charger.

    3.2kwp SE, .8 NW, .8 W. 15kwh Battery.

  • Registered Users Posts: 1,952 ✭✭✭SD_DRACULA

    I did the outdoor socket thing with a shelly switch until I got my openevse charger and the car didn't like the sudden stop of the charging, kept on sending me messages like WTF man 🤣

    Depends on the car, some don't even start the charging until you re-plug in the charge cable after a sudden loss of power.

  • Registered Users Posts: 1,392 ✭✭✭Big Lar


    So how does your openevse charger, work @SD_DRACULA ? do you raise and lower the charging rate as the solar is available without actually switching it off ?

  • Registered Users Posts: 1,952 ✭✭✭SD_DRACULA

    Yes it auto changes the power it sends based on export.

    You give it the MQTT topic of the grid (I have a shelly em on my mains feed which gives more or less instant import/export values)

    Only use it for night charging now, you can set schedules, amps you want to send over 6 - 48, etc

    And it integrates with home assistant seamlessly which is the main thing - you could have HA send over your solar data to it as well

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  • Registered Users Posts: 854 ✭✭✭Mr Q

    What brand of inverter do you have? Some can work with certain brands of smart plugs already.

  • Registered Users Posts: 1,392 ✭✭✭Big Lar

  • Registered Users Posts: 6,200 ✭✭✭zg3409

    If using a granny cable make sure socket used is brand new and don't plug out house end regularly, instead plug out car end, or house socket will wear quickly.

    Any relays would want to be crazy over rated if turning off an active load.

    I would have thought openevse with a sensor for export would be better and you can vary charge rate. I am not a fan of over complicating software. You could then over ride when you need a faster charge.

    You might pick up a cheap nom smart charger for the likes of 150 euro where you may be able to adjust charge rate. The old esb ones are rs485 programmable.

  • Registered Users Posts: 1,392 ✭✭✭Big Lar

    Working on trying this out at the moment

  • Registered Users Posts: 854 ✭✭✭Mr Q

    Not familiar with these but they seem popular in Ireland, someone else might know if there is smart plug that is compatible.

    I know you can do this with SMA and I think Solax did them in the past.

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  • Registered Users Posts: 1,392 ✭✭✭Big Lar

    For anyone thats interested,

    There are a few cloud options out there that can do this like but the cost is €5.00 per month but none of them seem to integrate with Solis, so a Shelly Em is also required at a cost of €130.00

    I have installed the eevc addon to HA @ a cost of €2.00 per month, which does the same thing nut also the Solis inverter is not supported, so I have installed a MQTT broker on HA but now working on how to get the evcc addon to read from that.

  • Registered Users Posts: 1,952 ✭✭✭SD_DRACULA

    The shelly EM is only about €60 or so and you're better off getting it as the Solis is feeding you lies on consumption, there is always grid "trickle" when bigger loads on the house happen and until "it wakes up" to respond so your import is never right but the shelly sees all 😁

    Fixes your MQTT problem too