block batterie E3DC, charging during flexible energy price charging from the grid

[jvistola]

Hi everybody,
is it possible to block that the batterie will be used from E3DC during flexible tarif charging my vehicle?
thx
Josef

[goebelmeier]

Currently it's not possible without 3rd party support. I'm doing this using Home Assistant, https://github.com/torbennehmer/hacs-e3dc and an automation which reacts to evcc using MQTT.

[docolli]

I fully agree, having this functionality in one place would be nice. However, as @goebelmeier has confirmed, E3DC is not willing to change anything to their modbus protocol, as they state "we have given you RSCP, now use it". And evcc has only implemented the E3DC modbus protocoll, which is currently sufficient to get the necessary data from the E3DC system. So no need to implement (the rather complicated RSCP protocol) currently into evcc.

[kwitt21]

@goebelmeier I´m running the same setup, E3DC system (with battery) together with EVCC and Home Assistant (with HACS-E3DC integration).

How long does it take until the battery is stoped after EVCC initiated loading?

@andig
Maybe it would be an idea for the EVCC team to set an MQTT "BlockBattery" flag if using the battery is prohibited. I think there might be some more logic to when this flag is set (e.g. setting it some seconds before loading is started to give the battery time to stop or when in "Ladeplanung" mode). I think it´s easy to develop and everyone could use this flag for individual purpose.

[VolkerK62]

@kwitt21 you can set batteryDischargeControl: true via API. Then the topic evcc/site/batteryMode shows the actual state (normal/hold).

[kwitt21]

@VolkerK62 Is it also possible to set this parameter via configuration? I would prefer to set permanently.
I also had a quick look into https://docs.evcc.io/docs/reference/api but couldn't find anything named "batteryDischargeControl".

[VolkerK62]

due to the massive changes in the last time, the doku it not up to date.
Have a look here https://github.com/evcc-io/evcc/blob/master/server/http.go
I set it once via API and it is permantently "on". I think it is persistant.

[docolli]

I'd rather set the RSCP parameter EMS WB_DISCHARGE_BAT_UNTIL corresponding to the evcc battery limits bufferSoc or prioritySoc.

Above this value the E3DC battery supports the loading of a E3DC Wallbox and supplies not only the house consumption, but also the wallbox power up to the max. power of the E3DC system.

If house battery Soc drops below this treshold, then the E3DC system still dynamically supports the house consumption, the wallbox power is coming then fully from the grid. So house consumption and wallbox power are independent and you still have the full use of the E3DC battery for your house. I like this more than completely blocking home battery usage, when I load my car.

But, you'd need an extra house automation system like Home Assistant or NodeRed to do so.

[kwitt21]

Wow! This solution would bring (nearly) all E3DC wallbox features even without having an (original) E3DC wallbox :-)

As far as i can see, both EVCC values (bufferSoc and prioritySoc) are MQTT announced.

Just setting the RSCP parameter EMS WB_DISCHARGE_BAT_UNTIL seems not to be supported by any Home Assistant Integration (like hacs-e3dc).

[docolli]

I am using https://github.com/pvtom/rscp2mqtt to get a lot of values from my E3DC system available via MQTT.

Don't know if this can help you, but there is also this projekt: https://github.com/git-kick/ioBroker.e3dc-rscp which supports the necessary RSCP Tag.

[docolli]

Wow! This solution would bring (nearly) all E3DC wallbox features even without having an (original) E3DC wallbox :-)

Don't get too excited! You still need an original E3DC Wallbox, since the E3DC system MUST know the actual wallbox power to be able to regulate battery output accordingly. I just synchronize the E3DC System battery limit to the values set in evcc with this external code.

[premultiply]

In theory we could emulate an E3DC wallbox (phoenix ev-cc-eth) as modbus slave and integrate it as HEMS like SMA.
This way it could get the charger metering values...

[kwitt21]

I´m using the MQTT evcc/site/batteryMode Topic (thnx to @VolkerK62) together with an Home Assistant (with HACS-E3DC integration) automation to disable the E3DC battery when loading and it works perfectly.

Activate MQTT BatteryHold (EVCC) announcement:
curl -X POST http://homeassistant.local:7070/api/batterydischargecontrol/true

Add an MQTT Binary Sensor for the battery hold status (configuration.yaml):

# MQTT
mqtt:
  binary_sensor:
    - name: "EVCC Hold Battery"
      state_topic: "evcc/site/batteryMode"
      payload_on: "hold"
      payload_off: "normal"

Automation to enable E3DC battery limit (I set it to 500W which is our normal consumption) when loading is startet:

alias: "S10X: Ladelimit setzen"
description: 
  Setzt ein Entladelimit sobald das Laden an der Wallbox gestartet wird. Damit
  soll verhindert werden, dass der Akku des Hauskraftwerks unnötig strapaziert
  wird.
trigger:
  - platform: state
    entity_id:
      - binary_sensor.evcc_hold_battery
    from: "off"
    to: "on"
condition: []
action:
  - service: e3dc_rscp.set_power_limits
    data:
      device_id: XYZ
      max_discharge: 500
mode: single

Automation to disable E3DC battery limit when finished loading:

alias: "S10X: Ladelimit löschen"
description: Löscht Ladelimits nachdem das Laden an der Wallbox beendet ist.
trigger:
  - platform: state
    entity_id:
      - binary_sensor.evcc_hold_battery
    from: "on"
    to: "off"
condition: []
action:
  - service: e3dc_rscp.clear_power_limits
    data:
      device_id: XYZ
mode: single