Marstek OpenAPI

[tonbor]

Use the new plugin Marstek open API. Working ok. But have a problem with the Energy Dashboard. Added Marstek battery. But the flow is the wrong way. Negative mains flow to battery. Besides the flow is from sun panels and not from house to marstek battery

[willemd]

Yes, that was noticed by another user as well. The energy dashboard expects the sign to be different and as far as I know that is not configurable in the energy dashboard.

Marstek uses negative power numbers of charging and positive for discharging in the Open API.

But it can easily be adapted in the plugin. You have two options:
1) adapt the python line where the value for that device type is processed and add a multiplication by -1. But then it will apply to all devices and values of that device type.
2) in the device dictionary at the beginning of the plugin code, modify the multiplier of that device from 1 to -1. Then it can be configured per device.

I have uploaded a new version to github a minute ago that now handles the multiplier correctly also for kWh and counter devices (for those devices the previous version did not look at the multiplier, which was wrong of course). I have not yet changed the multiplier in the dictionary. It also corrects the pv1_power value that is reported incorrectly by the Open API. (release notes in the code)

Also note that there is another illogical thing in the dashboard in the sense that charging from the net to the battery is shown with a negative number, while usage from the net to the house is shown as a positive number, even though both flows are away from the net.

[willemd]

Following on from the above, you will get the most correct energy dashboard if:
1) you leave the plugin unchanged and use the sign as per Marstek conventions
2) set up a device that holds the sum of all solar production, either connected to the Marstek or not
3) set up a device that holds the nett power of the marstek battery/batteries (solar power minus ongrid and offgrid power)
4) a dzvents script to perform the calculations, my own example is shown below

Code: Select all

sumOfSolarIDX=370  -- output device holding the sum of all solar production for use in energy dashboard
solarHouseIDX=3      -- devices holding solar production, inputs to the sum of the total
solarMarstekPv1IDX=326
solarMarstekPv2IDX=330
-- add more if you have pv3 and/or pv4 connected
MarstekOnGridIDX=349
MarstekOffGidIDX=350
nettBatteryIDX=371
return {
	on = {
		devices = {
			solarHouseIDX,
            MarstekOnGridIDX,-- only one Marstek devcie needed since they are updated at the same time
		}
	},
	logging = {
		level = domoticz.LOG_DEBUG,
		marker = 'solar sum',
	},
	execute = function(domoticz, device)
		--domoticz.log('Device ' .. device.name .. ' was changed', domoticz.LOG_INFO)
		sumOfSolarValue=domoticz.devices(solarHouseIDX).usage+domoticz.devices(solarMarstekPv1IDX).usage+domoticz.devices(solarMarstekPv2IDX).usage
		domoticz.devices(sumOfSolarIDX).updateElectricity(sumOfSolarValue)
		nettBatteryValue=domoticz.devices(solarMarstekPv1IDX).usage+domoticz.devices(solarMarstekPv2IDX).usage-domoticz.devices(MarstekOnGridIDX).usage-domoticz.devices(MarstekOffGidIDX).usage
		domoticz.devices(nettBatteryIDX).updateElectricity(nettBatteryValue)
	end
}

[eddieb]

Today I got V156 from Marstek ...
- still no response on local API

[manuloup]

Hi Willem,

Your plugin is great, thanks for it.

I just have problem when I try to change from mode autoself to manual through domoticz.

I would like to do that so I can force my battery to charge since the price is lower during the night for me.

I get this error message :

Code: Select all

2026-03-07 19:48:46.996 Error: Marstek Venus E: Change of mode failed, please check format of input parameters for conversion to integer.

I also added an issue on your github page.

I have no trouble in the other way, from manual to autoself.

Thanks for your precious help.

[willemd]

I also added an issue on your github page.

Please note further follow-up on github.

[wim57]

So, for some reason, there is something on UDP/30000 (tested with nmap) but not working on my Venus E v2

If someone has other findings, I would like to know the differences

Since a few days I have a Marstek Venus E 3.0. I got the same results: the plugin does not receive any data through the api.
I also tried the test tool of the Home Assistant plugin https://github.com/jaapp/ha-marstek-local-api and that does work.
So there must be something different in the use of the api, I will see if I can find out the difference.

[willemd]

So, for some reason, there is something on UDP/30000 (tested with nmap) but not working on my Venus E v2

If someone has other findings, I would like to know the differences

Since a few days I have a Marstek Venus E 3.0. I got the same results: the plugin does not receive any data through the api.
I also tried the test tool of the Home Assistant plugin https://github.com/jaapp/ha-marstek-local-api and that does work.
So there must be something different in the use of the api, I will see if I can find out the difference.

That is an interesting observation. I did a quick check and the core communication seems to be very different using the asyncio library and a lot more handling of possible exceptions. Have a look at this file specifically:
https://github.com/jaapp/ha-marstek-loc ... api/api.py
I might have a further look myself and do some testing (although on my Venus A my own Domoticz plugin is very stable at the moment).

[eddieb]

So, for some reason, there is something on UDP/30000 (tested with nmap) but not working on my Venus E v2

If someone has other findings, I would like to know the differences

Since a few days I have a Marstek Venus E 3.0. I got the same results: the plugin does not receive any data through the api.
I also tried the test tool of the Home Assistant plugin https://github.com/jaapp/ha-marstek-local-api and that does work.
So there must be something different in the use of the api, I will see if I can find out the difference.

WOW

I just did the same test and YES that tool discovers my Venus E 2 ... and reads a lot ...

Code: Select all

 $ python3 test/test_tool.py discover
================================================================================
Marstek Local API Integration - Standalone Test
================================================================================

Step 1: Discovering devices on network...
Broadcasting on port 30000...

✅ Found 1 device(s):

Device 1:
  Model:       VenusE
  IP Address:  192.168.x.x
  MAC:         acd929axxxxx
  Firmware:    v156

================================================================================
Testing Device 1: VenusE (192.168.x.x)
================================================================================

📋 Device Information
--------------------------------------------------------------------------------
  Device Model:      VenusE
  Firmware Version:  156
  BLE MAC:           acd929axxxxxx
  WiFi MAC:          488f5axxxxxx
  WiFi Name:         xxxxxx
  IP Address:        192.168.x.x

📶 WiFi Status
--------------------------------------------------------------------------------
  SSID:              xxxxxxxxxx
  Signal Strength:   -29 dBm
  IP Address:        192.168.x.x
  Gateway:           192.168.x.254
  Subnet Mask:       255.255.255.0
  DNS Server:        192.168.x.254

🔵 Bluetooth Status
--------------------------------------------------------------------------------
  State:             disconnect
  MAC Address:       acd929axxxxxx

🔋 Battery Status
--------------------------------------------------------------------------------
  State of Charge:        100%
  Temperature:            20.0°C
  Remaining Capacity:     5120.0 Wh
  Rated Capacity:         5120.0 Wh
  Charging Enabled:       False
  Discharging Enabled:    True

⚡ Energy System Status
--------------------------------------------------------------------------------
  Battery SOC:            100%
  Battery Capacity:       5120 Wh
  Battery Power:          N/A
  Battery State:          idle
  Battery Power In:       0 W
  Battery Power Out:      0 W
  Available Capacity:     0.0 Wh
  Grid Power:             0 W
  Off-Grid Power:         0 W
  Solar Power:            0 W
  Total Solar Energy:     0 Wh
  Total Grid Import:      875100.0 Wh
  Total Grid Export:      693800.0 Wh
  Total Load Energy:      0.0 Wh

⚙️  Operating Mode
--------------------------------------------------------------------------------
  Current Mode:           Auto
  Grid Power:             0 W
  Off-Grid Power:         0 W
  Battery SOC:            100%

📊 Energy Meter (CT) Status
--------------------------------------------------------------------------------
  CT Connected:           True
  Phase A Power:          -2478 W
  Phase B Power:          0 W
  Phase C Power:          0 W
  Total Power:            -2477 W

================================================================================
Test Complete!
================================================================================

SO there IS something working on UDP/30000

[willemd]

I confirm it also works on my Venus A and provides the same data as my plugin, although the test tool does not seem to cover the PV status (probably because it was originally developed for systems without MPPT connections). Should be easy to add, it seems present in the api and constants definitions.

I also noted the code mentions that Venus E requires unique messages IDs (which is not mentioned in the Open API spec). My current code always uses 0. Myabe there are more unique requirements for Venus E.

I will now investigate further and see what is needed to integrate it with my plugin to make the plugin suitable for more types of Marstek batteries.

[willemd]

For the moment I have adapted plugin.py and venus_v2_api.py to ensure increasing sequence number, which seems to be required for Venus E. Maybe someone is prepared to test this in the meantime.

Tomorrow I will create a new version to use the api from jaapp and publish that on github.

[wim57]

Well, I just got a firmware update for the battery: V135 to V144.
After the update test_api_readonly works ok, so I assume this new firmware corrected some errors.

[wim57]

For the moment I have adapted plugin.py and venus_v2_api.py to ensure increasing sequence number, which seems to be required for Venus E. Maybe someone is prepared to test this in the meantime.

Tomorrow I will create a new version to use the api from jaapp and publish that on github.

I've just tested this new version of the plugin (together with my new firmware V144). Now the plugin produces an error: 'Errors in getting Marstek Venus data. Check results.'
So, I think at least the plugin receives some data now.

[eddieb]

just updated the plugin :

2026-03-20 07:21:12.062 Marstek Api: Marstek Plugin getVenusData called
2026-03-20 07:21:12.062 Error: Marstek Api: Errors in getting Marstek Venus data. Check results.
2026-03-20 07:21:12.062 Marstek Api: Sending email alert....
2026-03-20 07:21:12.072 Status: Notification: 'ATTENTION: Venus communication data error'
2026-03-20 07:21:12.072 Notification sent (browser) => Success

[willemd]

just updated the plugin :

2026-03-20 07:21:12.062 Marstek Api: Marstek Plugin getVenusData called
2026-03-20 07:21:12.062 Error: Marstek Api: Errors in getting Marstek Venus data. Check results.
2026-03-20 07:21:12.062 Marstek Api: Sending email alert....
2026-03-20 07:21:12.072 Status: Notification: 'ATTENTION: Venus communication data error'
2026-03-20 07:21:12.072 Notification sent (browser) => Success

solved now. Added client as global variable on line 216.

[eddieb]

no luck yet

Code: Select all

2026-03-20 12:00:10.055  Marstek Api: onHeartbeat called
2026-03-20 12:00:29.783  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.783  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.785  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.785  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.786  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.786  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.786  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.787  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:29.787  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:00:40.093  Marstek Api: onHeartbeat called
2026-03-20 12:00:40.093  Marstek Api: Marstek Plugin getVenusData called
2026-03-20 12:01:01.105  Marstek Api: battery status data received: None
2026-03-20 12:01:03.039  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.039  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.041  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.042  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.042  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.042  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.042  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.043  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:03.044  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.022  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.023  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.025  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.025  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.026  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.026  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.026  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.028  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:04.028  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.403  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.403  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.404  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.405  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.405  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.405  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.405  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.406  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:05.406  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.299  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.299  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.300  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.301  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.301  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.301  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.301  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.302  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:06.302  Error: Invalid Number sValue: '%' for device idx: '%'
2026-03-20 12:01:22.123  Marstek Api: pv status data received: None
2026-03-20 12:01:43.137  Marstek Api: em status data received: None
2026-03-20 12:01:43.854  Error: Marstek Api hardware (15) thread seems to have ended unexpectedly

[willemd]

OK. that error message about invalid number sValue" is a Domoticz bug. If a P1 device is created via the plugin it reports that error until a first value is loaded. Normally it goes away quickly and never reoccurs. (was documented on github)

But unfortunately I still indeed see that the other data collection statements also fail, so better to switch it off again. I will now continue to look into integration with the api from jaapp.

[willemd]

For testing purposes I have now published a new version of the plugin that uses the API from https://github.com/jaapp/ha-marstek-local-api.

Maybe this works better for the Venus E.

Note:
1) I have published it in a separate repository: https://github.com/WillemD61/Marstek-Venus-E-plugin
2) Please copy the 3 files into the folder created by the regular Marstek Venus plugin, restart and activate the hardware.
3) Note I have not yet adapted the functionality to change modes, so for the moment this can only be used to read data from the Venus battery.
4) The code from jaapp does not do a full update every cycle.
5) I am including PV getstatus even if your system does not have PV MPPT connections. I would expected this not to be a problem.
6) I am getting more "thread seems to have ended unexpcetedly" warnings compared to the regular plugin, but am receiving data.

Please let me know how this works on Venus E. If possible, I suggest further issues handling on github.

[eddieb]

tested, gives errors ...
issue on github created

[wim57]

I just tested the latest version of the plugin andf, apart from the PV-error, it seems to work ok.

Strange thing with the battery temperature: at first the temperature is 18 degrees and later it jumps to 180 degrees. May be a bug in the Marstek api.