smart mode: how to stop home battery discharging in the ev

[bartmarchand1]

like the title says: what is the best method in smart mode to stop the home battery of discharging in the ev?

I want to use the home battery exlusive for the house and not for the car, when the battery discharges to a certain threshold.

[dingo35]

https://github.com/dingo35/SmartEVSE-3.5/blob/master/docs/configuration.md#home-battery-integration

You can use both REST API and MQTT to feed your battery currents, see manual.

[bartmarchand1]

yes I know but the manual says: "NOTE: The battery current is ONLY taken into account in SOLAR mode !!!"

I have noticed that the home battery is discharging to the car while in smart mode.

[dingo35]

Ok I traced it down, this limitation has been in there for years and I can't see why.

This version has the limitation taken out. I don't have testing capabilities at my current location, so please test extensively, also in Normal mode:
f9c7a09e.zip

[bartmarchand1]

I'll test it this weekend.
The ideal situation would be that from a certain state of charge onward, I can stop the battery from discharging only for the EV.
But that would require communication between the home battery and the charger.
I’ll think about how to solve this, because the battery must always remain available to compensate for the capacity tariff.

[dingo35]

Can you post your /config? There is a limitation on modbus Mainsmeters also..

[bartmarchand1]

these are the settings:
{ "version": "v3.10.0-315", "serialnr": 7866, "mode": "OFF", "mode_id": 0, "car_connected": false, "wifi": { "status": "WL_CONNECTED", "ssid": "#############", "rssi": -67, "bssid": "##############" }, "evse": { "temp": 20, "temp_max": 65, "connected": false, "access": 0, "mode": 1, "loadbl": 0, "pwm": 1024, "custombutton": false, "solar_stop_timer": 0, "state": "Ready to Charge", "state_id": 0, "error": "None", "error_id": 0, "rfidreader": "Rmt/OCPP", "nrofphases": 1, "rfid": "Ready to read card", "rfid_lastread": "###########" }, "settings": { "charge_current": 160, "override_current": 0, "current_min": 6, "current_max": 16, "current_main": 25, "current_max_circuit": 25, "current_max_sum_mains": 14, "max_sum_mains_time": 1, "solar_max_import": 11, "solar_start_current": 0, "solar_stop_time": 0, "enable_C2": "Always Off", "mains_meter": "API", "starttime": 0, "stoptime": 0, "repeat": 0, "lcdlock": 0, "lock": 0, "cablelock": 0 }, "mqtt": { "host": "192.168.1.110", "port": 1883, "topic_prefix": "SmartEVSE-7866", "username": "########", "password_set": true, "tls": false, "status": "Connected", "smartevse_server": false }, "ocpp": { "mode": "Enabled", "backend_url": "wss://ocpp.tapelectric.app/###########", "cb_id": "Charger_1", "auth_key": "", "auto_auth": "Disabled", "auto_auth_idtag": "", "status": "Connected" }, "home_battery": { "current": 0, "last_update": 1770382581 }, "ev_meter": { "description": "Eastron3P", "address": 101, "import_active_power": 0, "total_wh": 4657083, "charged_wh": 9274, "currents": { "TOTAL": 0, "L1": 0, "L2": 0, "L3": 0 }, "import_active_energy": 4657083, "export_active_energy": 0 }, "mains_meter": { "import_active_energy": 0, "export_active_energy": 0 }, "phase_currents": { "TOTAL": 94, "L1": -1, "L2": 5, "L3": 90, "last_data_update": 1770382581, "original_data": { "TOTAL": 94, "L1": -1, "L2": 5, "L3": 90 } }, "backlight": { "timer": 0, "status": "OFF" }, "color": { "off": { "R": 0, "G": 0, "B": 0 }, "normal": { "R": 0, "G": 255, "B": 0 }, "smart": { "R": 0, "G": 255, "B": 0 }, "solar": { "R": 255, "G": 170, "B": 0 }, "custom": { "R": 0, "G": 0, "B": 255 } } }``

[dingo35]

Ok you're on API so you should be fine

[bartmarchand1]

With this version, the car continued to charge even when the capacity rate was exceeded, and there was no power reduction.
result: capacity rate exceeded, additional costs...

[dingo35]

Yes I warned you I have no testing capabilities; that is why its called testing, you are on uncharted territory here so you must be on your guard.

I talked to the manufacturer and we concluded this is not going to work anyways in Smart mode.

What would happen: presuming your battery inverter tries to keep your current usage on a certain level, say zero-on-the-meter.

Now you start charging, say on MaxCurrent16A; the battery inverter starts to discharge 16A. You dont want this so you are feeding the MQTT battery current feed with this information.
This will lead to a correction of -16A, which would make available current 0A , and you would stop charging. Which you would expect in Solar mode, but not in Smart mode; in Smart mode you expect the charging to happen, perhaps not only on highest current, but slowly anyways.

So that is why battery current feeding should be limited to Solar mode only.

Too bad this contribution costs you money, but please be aware your contribution in money is nothing compared to mine in time....

[bartmarchand1]

I am very aware of how much time and energy such a project requires.
I am truly grateful for it.

[dingo35]

The solution to your problem is in the battery inverter: you should instruct it directly not to discharge when EV charging in Smart mode...

[bartmarchand1]

My solution is to add the battery's discharge current to the consumption meter's current when the battery has fallen below a certain SOC.
Not a nice solution, but it works for now, even when the charger is set to smart mode.