{"id":8259,"date":"2024-11-12T09:35:01","date_gmt":"2024-11-12T08:35:01","guid":{"rendered":"https:\/\/blog.fh-kaernten.at\/ingmarsretro\/2024\/11\/12\/pylontech-pv-battery-status-in-the-homeassistant\/"},"modified":"2025-01-05T18:25:28","modified_gmt":"2025-01-05T17:25:28","slug":"pylontech-pv-battery-status-in-the-homeassistant","status":"publish","type":"post","link":"https:\/\/blog.fh-kaernten.at\/ingmarsretro\/2024\/11\/12\/pylontech-pv-battery-status-in-the-homeassistant\/?lang=en","title":{"rendered":"Pylontech PV battery status in the HomeAssistant"},"content":{"rendered":"
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Anyone who has installed a photovoltaic system in their own home may even use an energy storage system. In this example, it is an off-grid system equipped with two modules from the manufacturer Pylontech. The Pylontech US3000C batteries have an output voltage of 48V. The nominal capacity is 3500Wh. The installed cells are LiFePO4 cells and the usable capacity is specified as 3374Wh according to the data sheet. The batteries are designed to be connected in parallel with other Pylontech batteries. The internally installed BMS (battery management system) communicates with the other Pylontech battery modules via a so-called \u201clink\u201d interface. A battery configured as a \u201cmaster\u201d handles the data exchange with the inverter. Here, Pylontech provides the CAN or RS485 bus as an interface. However, if you want information about the individual cells (voltages, currents, charges, temperatures, etc.), there is another interface on each module called \u201cConsole\u201d. This is an RS232 interface via which you can communicate directly with the battery’s BMS. This port is also used to update the firmware of the BMS. However, I STRONGLY advise against playing around with firmware updates and flash software. This is reserved for the manufacturer or the liable party.<\/p>\n

However, as this interface also provides a lot of information about the cells installed in the battery, this is an interesting approach. Initially, I had a laptop connected to a terminal and was able to discover and monitor the individual cell voltages and, above all, the possibly different charge status of the modules connected in parallel. So I thought it would be a good idea to have this information available in my home automation system, where it could be visualized and used for control purposes.<\/p>\n

As we geeks and technology enthusiasts are quite familiar with terms such as Homeassistant, Docker, Proxmox, HomeMatic, NodeRed etc., I thought that this data should also become entities in the Homeassistant. So a small new project was quickly created. My plan was to read the data from the serial interface and send it to the Home Assistant via MQTT.<\/p>\n

But before I start disassembling the data strings that come out via the serial port, I’ll have a look at the search engines. Perhaps someone else has already dealt with this topic. And that’s exactly what happened. I found what I was looking for on GitHub under the term \u201cpylontec2mqtt\u201d. A project is hosted at https:\/\/github.com\/irekzielinski\/Pylontech-Battery-Monitoring<\/a> that uses ESP8266 to collect the serial data from the port and sends it to the Homeassistant server via MQTT and Wifi. A fork with a further development of this project can be found at https:\/\/github.com\/hidaba\/PylontechMonitoring.<\/a><\/p>\n

Why am I publishing the project here on the blog despite the simple replica? I have optimized the circuit a little and packed it into a layout and adapted the code a little. I would like to share the result here. It was important to me to have a sensible structure on a circuit board that is connected with a USB A-B cable for the power supply and a LAN-RJ45 cable for the data connection. I wanted to use a \u201csolid\u201d USB connector (not the fragile mini or micro USB connectors)<\/p>\n

On a breadboard and with the usual development boards, I quickly \u201cknitted together\u201d a functional model so that I could adapt the software to it.<\/p>\n

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Functional sample on perforated grid<\/p><\/div>\n

So I first created a circuit diagram from the sketches in the Git project. There is a \u201creal\u201d RS232 level at the \u201cConsole\u201d interface, which is converted to a 5V TTL via the MAX3232 IC. The BSS123 FET is used to realize a level converter to 3.3V for each of the RX and TX signals.<\/p>\n

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pylontec2mqtt schematic<\/p><\/div>\n

The ESP8266 processes this 3.3V TTL level in the form of the Wemos D1Mini or WemosD1Pro development board, which is plugged onto the circuit board. I then packed the entire construction into a small plastic housing, which can be conveniently connected to the Pylontec and a USB power source via the LAN and USB cables.<\/p>\n

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Layout preview in designtool<\/p><\/div>\n

The layout design is shown in the picture above. The circuit board and the position of the components were checked again with the preview before production and then ordered from a trusted manufacturer.<\/p>\n

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Preview of the circuit board before production<\/p><\/div>\n

After barely two weeks of waiting, I had the empty circuit boards in my hands and was able to fit them with the components.<\/p>\n

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fully assembled circuit board<\/p><\/div>\n

The picture above shows the fully assembled board. The only thing missing here is the Wemos board with the ESP.<\/p>\n

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Comparison between functional model and first \u201cproduction model\u201d<\/p><\/div>\n

In the end, I plugged in a WemosD1 Pro, as this offers the option of connecting an external WiFi antenna and thus getting a reasonable wireless range.<\/p>\n

After flashing the software and commissioning, the Wemos web server can be accessed at the IP address specified in the code. Here you can also check whether the Pylontech battery is communicating with the Wemos. The result then looks like this.<\/p>\n

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Webseite of the WEMOS ESP<\/p><\/div>\n

Here you can see that both battery modules are recognized correctly. The next step is to check whether messages are being sent via the MQTT protocol. The IP address of the MQTT broker must also be specified in the Wemo code. In my setup, I have set up the MQTT Explorer in the Home Assistant to be able to check the MQTT functions quickly and easily.<\/p>\n

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MQTT Explorer<\/p><\/div>\n

The image above shows that the data also arrives correctly via MQTT. Now it is only necessary to create a sensor yaml file in the home assistant to make the topics available as entities. I have added the following code to configuration.yaml for this purpose:<\/p>\n

\n
mqtt:\r\n  sensor:\r\n#Pylontec Akku Serial Readout (ESP32 192.168.xxx.yyy)\r\n    - state_topic: \"ingmarsretro\/pylontec\/ESP_WiFi_RSSI\"\r\n      name: \"Pylontec_RSSI\"\r\n      unit_of_measurement: dB\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/availability\"\r\n      name: \"Pylontec_Status\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/currentDC\"\r\n      name: \"DC-Strom\"\r\n      unit_of_measurement: \"mA\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/getPowerDC\"  \r\n      name: \"getPower DC\"\r\n      unit_of_measurement: \"W\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/powerIN\"  \r\n      name: \"Power IN\"\r\n      unit_of_measurement: \"W\"  \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/estPowerAC\"\r\n      name: \"Pylontec_estPowerAC\"\r\n      unit_of_measurement: Watt  \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/soc\"\r\n      name: \"Pylontec_SOC\"\r\n      unit_of_measurement: \"%\"  \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/temp\"\r\n      name: \"Pylontec_temperature\"\r\n      unit_of_measurement: \"\u00b0C\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/battery_count\"\r\n      name: \"Pylontec_BatteryCount\"\r\n      unit_of_measurement: \"pcs\"      \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/base_state\"\r\n      name: \"Pylontec_BaseState\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/is_normal\"  \r\n      name: \"Pylontec_is_normal\"\r\n\r\n    - state_topic: \"ingmarsretro\/pylontec\/powerOUT\"\r\n      name: \"Pylontec_powerOUT\"\r\n      unit_of_measurement: Watt\r\n      \r\n# Pylontech battery module 0      \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/current\"\r\n      name: \"Pylontec_Battery0_current\"\r\n      unit_of_measurement: \"A\"\r\n\r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/voltage\"\r\n      name: \"Pylontec_Battery0_voltage\"\r\n      unit_of_measurement: \"V\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/soc\"\r\n      name: \"Pylontec_Battery0_soc\"\r\n      unit_of_measurement: \"%\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/charging\"\r\n      name: \"Pylontec_Battery0_charging\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/discharging\"\r\n      name: \"Pylontec_Battery0_discharging\"\r\n     \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/idle\"\r\n      name: \"Pylontec_Battery0_idle\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/state\"\r\n      name: \"Pylontec_Battery0_state\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/0\/temp\"\r\n      name: \"Pylontec_Battery0_temp\"\r\n      unit_of_measurement: \"\u00b0C\"\r\n      \r\n# Pylontech battery module 1      \r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/current\"\r\n      name: \"Pylontec_Battery1_current\"\r\n      unit_of_measurement: \"A\"\r\n\r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/voltage\"\r\n      name: \"Pylontec_Battery1_voltage\"\r\n      unit_of_measurement: \"V\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/soc\"\r\n      name: \"Pylontec_Battery1_soc\"\r\n      unit_of_measurement: \"%\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/charging\"\r\n      name: \"Pylontec_Battery1_charging\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/discharging\"\r\n      name: \"Pylontec_Battery1_discharging\"\r\n     \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/idle\"\r\n      name: \"Pylontec_Battery1_idle\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/state\"\r\n      name: \"Pylontec_Battery1_state\"\r\n      \r\n    - state_topic: \"ingmarsretro\/pylontec\/1\/temp\"\r\n      name: \"Pylontec_Battery1_temp\"\r\n      unit_of_measurement: \"\u00b0C\"\r\n      \r\n<\/code><\/pre>\n