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EV Charger Install with Solar+Battery in New Build Mid-Terrace (Integration & Monitoring challenge)

  • 10-04-2025 02:23PM
    #1
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭


    Hi all,

    I'm looking for some advice on the best way to install an EV charger at my new build mid-terrace house in Dublin. I have an existing solar PV and adding a large battery soon.

    My goal is to install an EV charger (at the front of the house) and integrate it properly with my solar/battery system.

    The Main Challenge:

    I want my inverter/monitoring system (Deye) to accurately "see" the load from the EV charger. This is important for:

    1. Accurate energy monitoring (seeing total consumption vs. solar generation/battery usage).
    2. Allowing the house battery to discharge to power the EV if needed/desired.
    3. Effectively utilizing off-peak EV charging tariffs

    Potential Options & Problems:

    1. Direct Connection to Meter Tails: I know one option is connecting the EV charger supply directly to the meter tails (before my main consumer unit and the system's CT clamp).
      • Problem: My understanding is that with this setup, my solar/battery inverter won't see the EV load at all. This messes up monitoring. Also, if I charge the EV on an off-peak night rate, the meter sees the load, but my system doesn't – potentially leading the battery to also try and charge from the grid simultaneously if it's scheduled or configured to do so based on its own logic (which doesn't see the EV load). Critically, the battery cannot discharge to power the EV as the connection bypasses the consumer unit where the battery feeds in. This feels like a "last resort" method that sacrifices key integration benefits.
    2. Dedicated Circuit from Consumer Unit: The seemingly "correct" way would be to run a dedicated circuit for the EV charger directly from my main consumer unit (so it's located after the system's main CT clamp).
      • Problem: My consumer unit is likely located at the back of the house. Being a mid-terrace, routing is tricky. Is the only viable path realistically going up into the attic, across the house, and down the front exterior wall? Are there common/better ways to do this in terraced houses?
    3. Alternative Monitoring / Other Solutions?
      • Are there reliable long-range wireless CT clamps that could be placed on the meter tails (or the EV charger feed if connected there) and reliably communicate back to my Deye Inverter? Would this solve only the monitoring issue, or could it potentially help with smart control too? Would the battery still be unable to power the EV in this scenario if the charger is fed directly from the meter?
      • Are there specific EV chargers that are better designed to handle this integration challenge, perhaps with their own CT clamps that can communicate effectively with third-party solar systems?
      • Any other clever solutions I haven't considered?
    • What's the generally recommended approach for this situation in Ireland, balancing cost, complexity, and proper system integration?
    • Does anyone have experience routing EV charger cables in mid-terraces (over roofs/through attics)? Any pitfalls or tips?
    • Can anyone recommend reliable wireless CT solutions compatible with Deye
    • Are there specific EV charger models known for good integration with solar/battery systems like mine?

    Thanks in advance for any insights or advice!



Comments

  • #2
    Jonathan
    Moderators, Education Moderators, Home & Garden Moderators Posts: 8,299 Mod ✭✭✭✭Jonathan


    I effectively have this setup. My Zappi is taken from the meter cabinet but the inverter CT is in the consumer unit and can't see Zappi load. All works fine and I use myenergi in Home Assistant to monitor the house load.

    Once ESBN enable the P1 port on the smart meters, that is where you are going to want to source your monitoring data anyway.



  • #3
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭Abromavich


    Yeah I see your point but I still think it will be problematic to charge from the battery, as the inverters meter is in the consumer unit and it wont communicate with the P1 port on the smart meter..

    I think only way is to connect the charger back to the consumer unit.



  • #4
    graememk
    Moderators, Home & Garden Moderators Posts: 7,012 Mod ✭✭✭✭graememk


    Will you ever want to charge the car from the house battery?

    If not, you can just let the charger detect the excess and charge accordingly.

    There is a few wireless solutions that takes the rs485 modbus from the meter and either routes it via TCP (eg house network, over lan or WiFi) or loRa wireless)



  • #5
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭Abromavich


    https://www.boards.ie/discussion/comment/123346783#Comment_123346783

    Unlikely - nominally I want to charge only using the night rate. The issue then would be that Id also be charging the battery at 12kw so the EV charger wouldnt be able to charge as it would see a maxed load.

    Any easy workaround Im not thinking of? It would be so easy to just install direct to the meter box….

    So are you suggesting install the Eastron SDM230 or some other compatible meter (with DEYE) at the meter box and then output the modbus RS485 to my wireless house network? Im thinking this would be difficult to do with the DEYE. Sorry if im misunderstanding you.



  • #6
    graememk
    Moderators, Home & Garden Moderators Posts: 7,012 Mod ✭✭✭✭graememk


    https://www.boards.ie/discussion/comment/123346847#Comment_123346847

    Yeah thats exactly what you can do, move the meter, or use a CT variant of the meter, but still same issue applies.

    you can also use a CT version of the meter the sdm120 or something but same issue. That CT needs to be in the meter box. (or use a CT meter and somehow fish a cat6 cable to the meter box.)


    As for divving up the power, Somethings got to give, if you charge the car at a lower rate or charge batteries at a lower rate one or the other.



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  • #7
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭Abromavich


    https://www.boards.ie/discussion/comment/123346980#Comment_123346980

    I like your ideas - I think trying over wifi or fishing a cat 6 sounds much better then connecting the charger all the way back to the consumer unit. Ill research using Modbus Gateways (RS485 to Wi-Fi) as I have a router right beside the inverter with 1gb wifi.

    Esentially using the EV night rate I want the Battery Charge = 12kw - house load - EV charger

    Is the above doable? - can I force the ev charger to draw its full 7kW which would then result in the battery reducing its charge. Im concerned the EV charger will see the 12kW power draw from the battery and not charge.



  • #8
    Jonathan
    Moderators, Education Moderators, Home & Garden Moderators Posts: 8,299 Mod ✭✭✭✭Jonathan


    https://www.boards.ie/discussion/comment/123348987#Comment_123348987

    Do you do high milage? Would you not just set a fixed battery charge current and let the EV charger derate itself to stick within the 12kW limit? That is my setup and it is the easiest and most robust. It is failsafe too as it isn't reliant on any automations to alter the charge current.



  • #9
    graememk
    Moderators, Home & Garden Moderators Posts: 7,012 Mod ✭✭✭✭graememk


    The deye does have grid limiting, but to do that it needs to see the EV charger load.



  • #10
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭Abromavich


    https://www.boards.ie/discussion/comment/123350547#Comment_123350547

    So as long as the charger sits behind the Eastron meter im good? I can setup so that battery charge derates as the EV draws charge?



  • #11
    Abromavich
    Registered Users, Registered Users 2 Posts: 145 ✭✭Abromavich


    Ive been thinking about this and I see 2 possible ways to have EV priority during the EV window:

    • (DLB - Dynamic load balancing)
    • Different DLB Limits: Set the inverter's total household DLB limit lower than the EV charger's limit (but both safely below the main fuse). This forces the inverter to reduce power first, indirectly prioritising the EV.
    • Same DLB Limit + Staggered Start: Configure both devices with the same correct DLB limit based on the main fuse, then schedule the EV (2am) to start charging a few minutes before the inverter (2.05am). This safely prioritises the EV as it establishes its load first, forcing the inverter to automatically limit itself when it starts if capacity is constrained.
    • Any thoughts on the above? Ive been looking at the Ohme Home pro, any pitfalls with using this charger?
    Post edited by Abromavich on


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