ESPHome Battery Monitor BM6 Integration

ESPHome external component for the BM6 Battery Monitor (and compatible BM200 models) using BLE communication. Optimized for ESP32-S3 and the ESP-IDF framework.

Features

• Voltage Monitoring: Real-time battery voltage ($0.01V$ precision).
• Temperature Sensing: Internal battery temperature reporting in °C.
• Battery Percentage (SoC): State of Charge calculation ($0-100%$).
• Status Indicators: Binary sensors for Charging, and Low Voltage
• NimBLE Support: Uses the memory-efficient NimBLE stack for better performance on the S3.

Board & ESPHome Version

• Board: ESP32-S3 (e.g., Lolin S3 Pro, DevKitC-1).
• ESPHome: 2026.2.0 or newer.
• Framework: ESP-IDF.

Installation

Add this to your ESPHome configuration:

external_components:
  - source: github://andrewbackway/esphome-bm6_ble@main

Configuration

1. Global Bluetooth Setup

The esp32_ble_tracker discovers the device, while ble_client manages the authenticated connection.

YAML

esp32:
  board: lolin_s3_pro
  framework:
    type: esp-idf
    sdkconfig_options:
      CONFIG_BT_NIMBLE_ENABLED: y

esp32_ble_tracker:
  scan_parameters:
    active: true

ble_client:
  - mac_address: "AA:BB:CC:DD:EE:FF" # Replace with your BM6 MAC
    id: bm6_ble

bm6_ble:
  id: bm6_1
  ble_client_id: bm6_ble

2. Sensor Configuration

Define each entity using the type field to link it to the BM6 data stream.

Numeric Sensors (sensor)

Type	Description	Unit	Default Icon
VOLTAGE	Battery voltage	V	mdi:flash
TEMPERATURE	Battery temperature	°C	mdi:thermometer
BATTERY_LEVEL	State of Charge	%	mdi:battery

YAML

sensor:
  - platform: bm6_ble
    bm6_ble_id: bm6_1
    type: VOLTAGE
    name: "Battery Voltage"

  - platform: bm6_ble
    bm6_ble_id: bm6_1
    type: BATTERY_LEVEL
    name: "Battery SoC"

  - platform: bm6_ble
    bm6_ble_id: bm6_1
    type: BATTERY_LEVEL
    name: "Battery SoC"

Binary Sensors (binary_sensor)

Type	Description	Device Class
CHARGING	Battery is charging	battery_charging
LOW_VOLTAGE	Voltage below threshold	problem

YAML

binary_sensor:
  - platform: bm6_ble
    bm6_ble_id: bm6_hub
    type: CHARGING
    name: "Battery Charging"

  - platform: bm6_ble
    bm6_ble_id: bm6_1
    type: LOW_VOLTAGE
    name: "Low Voltage Alert"

License

MIT License