ECU-C - Energy Numbers

[TaylorTWBrown]

Hi folks,

The integration for my ECU-C reports power (current watts) from the CT clamps. However, it doesn't include energy (cumulative watts) for import and export. Production kWh is included in the integration.

Because of this, I can't use the ECU-C in Home Assistant's energy dashboard. Is this data available, and could it be added?

Love this integration! Thanks for making my system more useful!!

[ricoyouhou]

Hi,
Same as Taylor.
My ECU-C + 3kW DS3 inverters integration went smootly except there is no KPI for the energy sent back to Grid (in kWh) so it is not possible to add this counter in HA energy dashboard.
The value is well known when you log into https://apsystemsema.com/ so there should be a way to retrieve it somehow.
Any insight on this ?

Thanks a lot for this integration.
Enrique

[HAEdwin]

Ok, but is this something to be calculated or should it allready be in the data somewhere. I need more directions to add it because I do not own an ECU-C.

[TaylorTWBrown]

It should be available in the data, I think this is also exposed over modbus, but I'm not super familiar with the APSystems undocumented API.

I'll do some research and see if I can find this API endpoint.

If you also have any tips or know good documentation for poking through the API I'll start playing around.

[ricoyouhou]

Some documentation are enclosed, mainly API stuff.
Apsystems_OpenAPI_User_Manual_End_User_EN.pdf
Apsystems EMA API operation manual.pdf

APsystemsECUSensor(
coordinator,
ecu,
"lifetime_energy",
label=f"{ecu.ecu.ecu_id} Lifetime Energy",
unit=UnitOfEnergy.KILO_WATT_HOUR,
devclass=SensorDeviceClass.ENERGY,
icon=SOLAR_ICON,
stateclass=SensorStateClass.TOTAL_INCREASING,
),

This one is working fine and properly retrieved in HA.

How about trying these two options ?

• lifetime_energy_exported
• lifetime_exported_energy

Probably lifetime_energy is splitted with "more spec" sensor to be able to display this KPIs.
Let me know what you think and how we can help to test it.

[ricoyouhou]

https://file.apsystemsema.com:8083/apsystems/resource/openapi/Apsystems_OpenAPI_User_Manual_End_User_EN.pdf
3.4 Meter-level Data API Page 17

/user/api/v2/systems/{sid}/devices/meter/summary/{eid}
This request will return the accumulative energy reported by an Meter ECU that you searchedfor.

{ "code": 0, "data":
{
"today": { "consumed": "394.408090", "exported": "0.000000", "imported": "560.523540", "produced": "833.884550"
},
"month": { "consumed": "394.408090", "exported": "0.000000", "imported": "560.523540", "produced": "833.884550"
},
"year": { "consumed": "6394.408090", "exported": "0.000000", "imported": "4560.523540", "produced": "1833.884550"
},
"lifetime": { "consumed": "6394.458090", "exported": "0.000000", "imported": "4561.643540", "produced": "1833.894550"
}
}
}

[HAEdwin]

Yes, [custom_components.solar_optimizer.switch] is the wrong integration search/wait for messages from [custom_components.apsystems_ecu_reader]

I've searched the code but can't find a related command, so at first glance, this appears to be available solely through the REST API. The number of API calls allowed is limited, making it unusable for values ​​that are updated frequently. The integration does not use the REST API. Most values can be calculated in the Integration so if you find the base values in Watts I can calculate the values in kWh and add the sensors: consumed, exported, imported and produced from there on a daily bases at first.

[ricoyouhou]

Yes, [custom_components.solar_optimizer.switch] is the wrong integration search/wait for messages from [custom_components.apsystems_ecu_reader]

2025-12-30 05:07:10.078 WARNING (MainThread) [custom_components.apsystems_ecu_reader] Using cached data for ECU 215000087933: Could not retrieve ECU base data - None
I think I have a problem here, I need to double-check.

I've searched the code but can't find a related command, so at first glance, this appears to be available solely through the REST API. The number of API calls allowed is limited, making it unusable for values ​​that are updated frequently. The integration does not use the REST API. Most values can be calculated in the Integration so if you find the base values in Watts I can calculate the values in kWh and add the sensors: consumed, exported, imported and produced from there on a daily bases at first.

Sure let's try that if you can.
I think HA is expecting a "lifetime" value that is always incrementing, so that it can keep track of the exported energy on daily basis.
If you store that value everyday at midnight and the next day you start from this value instead of zero, it could do the trick ? (pls forgive me if I over-simplify everything ^^)

Working sensors that can be used for calculation :

• Consumed A (W)
• Grid CT A (W) can be positive of negative (negative = exported)
• Production CT A (W)

Basically, if you create a new variable/sensor "Exported A" that sum everytime Grid CT A is negative (every 5 min), that could work (assuming my understanding is correct and the energy in kWh will be the SUM of the 12 values you have during this hour).

[HAEdwin]

2025-12-30 05:07:10.078 WARNING (MainThread) [custom_components.apsystems_ecu_reader] Using cached data for ECU 215000087933: Could not retrieve ECU base data - None
This can happen now and then, nothing to worry about.

Indeed, CT sensors are already returned by the integration (Produced CT A..C, Grid CT A..C and Consumed A..C)
Like @TaylorTWBrown noticed Production is already included. It's beginning to dawn on me now, I "just" have to add the Energy sensors for Grid CT A..C and Consumed A..C). These sensors have to be Lifetime or Daily and in kWh.

[HAEdwin]

Use the following at your own risk, if it makes you uncomfortable, don't do it.
Just curious, what happens when you send the ASCII string: "APS1100280008215000087933END\n" to port 8899 on the IP-address of your ECU-C using for example Packet Sender?

You should get something returned like: APS11012000080002 and a bunch of number that might match up with power values.

[ricoyouhou]

It's beginning to dawn on me now, I "just" have to add the Energy sensors for Grid CT A..C and Consumed A..C

Yes, exactly. Energy sensor for negative Grid CT A..C will be the amount of energy sent back to grid and will match our needs for HA.
Note : from my pov, Consumed energy is not needed because HA already sum the energy taken from grid (usually already available with your electricity meter) + the one produced by your solar panels "Lifetime energy" (already available with your integration). The only missing part is the energy you send back to grid and don't use locally.

[HAEdwin]

Great, negative grid CT A..C will be used to calculate export in kWh. It will be a persistant value and will increment lifetime - let's start with that. The sensor names will be something like LifeTime Energie Export A..C.

I tried the command I mentioned above earlier (with the ECU-ID of my ECU-R) but all it does is return zero's so I guess it's not compatible with my ECU-R.

[HAEdwin]

@TaylorTWBrown and @TaylorTWBrown

I've added the three sensors:

• lifetime_energy_export_a - Phase A energy export tracking
• lifetime_energy_export_b - Phase B energy export tracking
• lifetime_energy_export_c - Phase C energy export tracking

Properties:

• Energy Unit in kWh
• Persistent (survives a Home Assistant restart)
• Increases only on negative grid CT A..C values (no daily reset)
• MDI icon added ("mdi:transmission-tower-import")

Please test them for me by updating sensor.py and const.py from this location:
https://github.com/HAEdwin/homeassistant-apsystems_ecu_reader/tree/main/custom_components/apsystems_ecu_reader
(don't forget to restart Home Assistant after updating).

If you have any questions or comments, please let me know.

[ricoyouhou]

It looks ok !
I will compare HA value with EMA value at the end of the day and keep you updated.

[HAEdwin]

Great, thanks for the feedback and image! I do expect there will be small differences due to calculation differences between the local calculation and the calculation on the EMA side, and also due to possible "missed" data.

Btw, does the value reset when you restart Home Assistant? I haven't tested that to be honest.

[ricoyouhou]

Hi,
Quick update with today's values.

EMA energy produced : 7.74kWh
EMA energy exported : 0.56kWh

HA energy produced : 8.24kWh
HA energy exported (new sensor) : 0.27kWh

Delta is about 6% for produced but 50% for exported.
I restarted HA and value are indeed persistant.

If you need more "data", feel free to ask.

[HAEdwin]

Thanks for the feedback, indeed some accuracy is now added to sensor.py by conditionally applying trapezoidal calculations. Though one might expect differences:

• ECU samples taken by the integration
• ECU samples taken and pushed to EMA by the ECU

The time between the two actions will vary so different values are also insurmountable.

If you like, download the changed sensor.py, install and restart HA. Hopefully you are able to repeat the test you've done yesterday and values will be closer together.

[ricoyouhou]

I have updated sensor.py.
Let's wait tomorrow evening with new data.