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Hoymiles MS-A2

The Hoymiles MS-A2 communicates with Omnibattery through the MQTT integration already configured in Home Assistant. Omnibattery does not need the broker's host, port or credentials; Home Assistant handles the MQTT connection.

Prerequisites

Before adding the battery:

  • commission the MS-A2 in S-Miles Home;
  • use firmware that exposes MQTT Service;
  • configure a local MQTT broker through Home Assistant;
  • make the broker reachable from the MS-A2;
  • note the complete MQTT device ID, normally similar to MSA-280024341346.

The complete Hoymiles installation guide covers the electrical installation, S-Miles Home, MQTT and verification steps.

Connection

Choose Hoymiles MS-A2 as the brand and enter only a descriptive name and the full MQTT device ID. The connection test listens for live telemetry through Home Assistant.

Field Description
Name Name used for the battery device
MQTT device ID Full MS-A2 ID, including the MSA- prefix

No IP address, HTTP port, MQTT sensor or manual MQTT automation is required.

Capacity and limits

An individual MS-A2 has a nominal capacity of 2.24 kWh; a supported paired system normally uses 4.48 kWh. Enter the applicable nominal capacity in the limits step.

The power envelope is detected from MQTT and capped at 2000 W; a standalone unit is normally limited to 1000 W in both directions. The common limits also include maximum SOC, minimum SOC and charge hysteresis. The default minimum SOC is 10%.

The MQTT protocol does not expose writable SOC cutoffs or individual cell voltages. Omnibattery therefore enforces SOC limits in software, and Marstek's cell-balance and voltage-taper features are unavailable for the MS-A2.

For runtime controls and system limits, see Battery configuration.