Pylontech in Home Assistant

What you need

Choose your integration

Both options are set up from the device's Settings page (http://pylon-monitor.local/settings or http://<DEVICE-IP>/settings). Pick one — they are independent.

Option 1 — MQTT auto-discovery

Recommended if you use the Mosquitto broker add-on in Home Assistant. As soon as the device is connected to the broker, it publishes standard discovery messages on homeassistant/sensor/… and the sensors appear under Settings → Devices & services → MQTT within seconds, grouped under a single device called Pylon-Monitor.

1. Fill in 4 fields on the device

On the device's Settings page, find the Home Assistant — MQTT card and fill in these fields (labels exactly as the device shows them):

Click Save changes. A few seconds later the Home Assistant (MQTT) line of the device's dashboard shows Connected and the sensors below are created — no entity to configure by hand. To turn MQTT off, empty Broker IP and save.

2. The sensors Home Assistant creates

The device name (default pylon-monitor, changeable in Settings) is used as the topic prefix. If you changed it, replace pylon-monitor below with yours.

All of them read their value from a single retained state topic, refreshed after every battery reading:

pylon-monitor/state

The combined payload looks like this:

{
  "soc": 94,
  "soh": 96,
  "voltage": 48.62,
  "current": -7.20,
  "power": -350.1,
  "temp": 23.4,
  "mostemp": 28.1,
  "cycles": 486,
  "celldelta": 12,
  "units": 2,
  "state": "Discharging",
  "hw": "gen2",
  "pack": "lv"
}

3. Several batteries? One sensor set per battery

As soon as your pack has more than one Pylontech battery, the device also creates 5 sensors per battery — Battery 1 SOC, Battery 1 SOH, Battery 1 cycles, Battery 1 voltage, Battery 1 state, then Battery 2, 3… — each on its own topic (pylon-monitor/battery1/state, pylon-monitor/battery2/state…). Ideal for spotting the one battery that ages faster than the others.

pylon-monitor/battery1/state
{ "voltage": 48.61, "current": -3.60, "power": -175.0, "soc": 94, "soh": 97,
  "cycles": 480, "charge_cnt": 391, "discharge_cnt": 0, "state": "Discharging",
  "model": "US3000C", "bms_sw": "…", "serial": "…",
  "cell_min_mv": 3238, "cell_max_mv": 3247, "cell_delta_mv": 9, "cell_count": 15 }

These sensors also carry attributes, visible in each sensor's detail view: battery model, BMS version, serial number and — once the cells have been read — lowest and highest cell voltage and the gap between them. That's how you tell “Battery 3” from “Battery 4” without extra entities.

The device also keeps an availability topic with a Last Will: if it loses power or WiFi, every sensor turns “unavailable” in Home Assistant instead of silently freezing on its last value.

pylon-monitor/status  →  "online" (retained)  |  "offline" (Last Will, retained)

Option 2 — REST API

No MQTT broker needed. Home Assistant's built-in rest integration reads the device every 30 seconds. Easiest: copy the block from the Home Assistant — REST card of the device's Settings page — it already contains your IP and one SOH + cycles pair for every battery actually detected. The version below is the same template for a 2-battery pack. Since firmware 3.4.0 (Lite 1.1.0, generation 1: 3.1), /api.json requires your access key — the block copied from the device already contains ?key=…. If you set up REST before updating, add ?key=<your Access key> (Settings → Public JSON access) to the resource: line. MQTT is not affected.

The JSON returned by the device

GET http://<DEVICE-IP>/api.json?key=<ACCESS-KEY>

{
  "system": "pylon-monitor",
  "firmware": "3.3.2",
  "hw": "gen2",
  "battery_link": true,
  "summary": {
    "soc": 94,
    "voltage": 48.62,
    "current": -7.20,
    "power": -350.10,
    "state": "Discharging",
    "units": 2
  },
  "health": {
    "soh": 96,
    "cycles": 486,
    "charge_cnt": 782,
    "discharge_cnt": 0
  },
  "unitsDetail": [
    { "soc": 94, "soh": 97, "cycles": 480, "model": "US3000C", "...": "..." },
    { "soc": 94, "soh": 95, "cycles": 492, "model": "US3000C", "...": "..." }
  ]
}

Trimmed for readability: the full response also contains temps, cells, alarms and net, and unitsDetail gives voltage, current, SOC, SOH, cycles, model and serial number for each battery (present when the pack has more than one). Careful: SOH is under health, not under summary — a classic copy-paste mistake.

Paste this into configuration.yaml

# Access key: device Settings > Public JSON access (required since
# firmware 3.4.0 / Lite 1.1.0 / gen. 1 3.1). The block generated by the
# device's own Settings page already contains it.
rest:
  - resource: http://<DEVICE-IP>/api.json?key=<ACCESS-KEY>
    scan_interval: 30
    sensor:
      - name: "Pylontech SOC"
        unique_id: pylontech_soc
        value_template: "{{ value_json.summary.soc }}"
        unit_of_measurement: "%"
        device_class: battery
        state_class: measurement
      - name: "Pylontech SOH"
        unique_id: pylontech_soh
        value_template: "{{ value_json.health.soh }}"
        unit_of_measurement: "%"
        state_class: measurement
      - name: "Pylontech Voltage"
        unique_id: pylontech_voltage
        value_template: "{{ value_json.summary.voltage }}"
        unit_of_measurement: "V"
        device_class: voltage
        state_class: measurement
      - name: "Pylontech Current"
        unique_id: pylontech_current
        value_template: "{{ value_json.summary.current }}"
        unit_of_measurement: "A"
        device_class: current
        state_class: measurement
      - name: "Pylontech Power"
        unique_id: pylontech_power
        value_template: "{{ value_json.summary.power }}"
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement
      - name: "Pylontech State"
        unique_id: pylontech_state
        value_template: "{{ value_json.summary.state }}"
      # One SOH + cycles pair per battery (only on a pack of 2 or more):
      - name: "Pylontech Battery 1 SOH"
        unique_id: pylontech_battery1_soh
        value_template: "{{ value_json.unitsDetail[0].soh }}"
        unit_of_measurement: "%"
        state_class: measurement
      - name: "Pylontech Battery 1 cycles"
        unique_id: pylontech_battery1_cycles
        value_template: "{{ value_json.unitsDetail[0].cycles }}"
        state_class: measurement
      - name: "Pylontech Battery 2 SOH"
        unique_id: pylontech_battery2_soh
        value_template: "{{ value_json.unitsDetail[1].soh }}"
        unit_of_measurement: "%"
        state_class: measurement
      - name: "Pylontech Battery 2 cycles"
        unique_id: pylontech_battery2_cycles
        value_template: "{{ value_json.unitsDetail[1].cycles }}"
        state_class: measurement

Restart Home Assistant (Developer tools → Restart). The sensors appear under Settings → Devices & services → Entities — search for pylontech.

Energy dashboard

For a battery, Home Assistant's Energy dashboard wants two counters in kWh: energy charged in and energy discharged out. The Pylon-Monitor provides the battery power in W (positive = charging, negative = discharging), so you create them once, with helpers:

1. Split the power in two with two template sensors: charge power = the positive part, discharge power = the negative part turned positive.
2. Turn each one into kWh with an Integral helper (Riemann sum), metric prefix “k”, method “Left”.
3. In Settings → Dashboards → Energy, under Battery storage, add the two counters: energy going in, energy going out.

The same in YAML (MQTT entity names; with option 2 use sensor.pylontech_power):

template:
  - sensor:
      - name: "Battery charge power"
        unique_id: pylontech_charge_power
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement
        state: "{{ [states('sensor.pylon_monitor_battery_power') | float(0), 0] | max }}"
      - name: "Battery discharge power"
        unique_id: pylontech_discharge_power
        unit_of_measurement: "W"
        device_class: power
        state_class: measurement
        state: "{{ [0 - (states('sensor.pylon_monitor_battery_power') | float(0)), 0] | max }}"

sensor:
  - platform: integration
    source: sensor.battery_charge_power
    name: "Battery energy in"
    unique_id: pylontech_energy_in
    unit_prefix: k
    round: 2
    method: left
  - platform: integration
    source: sensor.battery_discharge_power
    name: "Battery energy out"
    unique_id: pylontech_energy_out
    unit_prefix: k
    round: 2
    method: left

Check the exact name of your power sensor in Settings → Entities (search for “power”): it differs if you renamed the device or have several Pylon-Monitors.

Automation generator

Pick what to watch, set the threshold, choose what happens: the YAML is written for you with the real Pylon-Monitor sensor names. The default is the classic one, a notification when the battery drops below 20 %.

Same idea with Battery state, Cell imbalance (for example above 50 mV) or sensors staying unavailable for more than 10 minutes — the sign the device is offline.

Node-RED, Jeedom and others

Node-RED — an http request node, method GET, URL http://<DEVICE-IP>/api.json?key=<ACCESS-KEY>, return “a parsed JSON object”, then read msg.payload.summary.soc (or any other field). With MQTT set up, an mqtt in node on pylon-monitor/state is even simpler: no polling.

Jeedom — install the JSON plugin, point a device at http://<DEVICE-IP>/api.json?key=<ACCESS-KEY> and map paths to commands (e.g. summary>soc, summary>voltage, summary>state).

Anything else — openHAB, ioBroker, Domoticz, EVCC or your own scripts: anything that reads MQTT or an HTTP JSON endpoint works with the same topics and the same /api.json.

Questions