MMBC v0.2.1 – Discharge Block Control

🟢 MMBC v0.2.1 – Discharge Block Control

Release date: 2025-06-28

This release adds a new control mechanism to block the discharge of the battery (e.g. while EV fast loading)

✨ New Features

• 🔌 Discharge Block Control via MQTT

  • MMBC can now be instructed to block battery discharge while still allowing charging.
  • Use case: prevent battery from discharging while an EV is fast-charging.
  • Controlled via MQTT topic: mmbc/control/block_discharge

• 🏠 Home Assistant Switch Integration

  • A new MQTT switch entity (switch.mmbc_block_discharge) allows toggling discharge block from the HA UI.
  • Switch stays in sync even when controlled externally (e.g. by EVCC).

📡 MQTT Topics Added

Topic	Direction	Description
mmbc/control/block_discharge	⬇️ Sub	Command to block/unblock discharge
mmbc/status/discharge_blocked	⬆️ Pub	Current state of the discharge block

See full list of topics in the MQTT Topics Table.

🔧 Setup Notes

To use the new discharge control:

1. Ensure your Home Assistant is set up for MQTT discovery
2. Restart MMBC to publish the discovery message
3. Use the new switch.mmbc_block_discharge to toggle from HA
4. Or publish directly to mmbc/control/block_discharge from EVCC or automations

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