Home Assistant Add-on: BatMON

Monitor various Battery management systems (BMS) over Bluetooth. This add-on reads the BMS and sends sensor data through MQTT to Home Assistant. Using bluetooth on the Home Assistant host system, it does not need any additional hardware.

I created this to compare BMS readings for a detailed evaluation of BMS reliability and accuracy.

Features

• Uses Bluetooth Low-Energy (BLE) for wireless communication
• Records SoC, Current, Power, individual cell voltages and temperatures
• Monitor multiple devices at the same time
• MQTT Discovery

Supported Devices (bluetooth)

• JK BMS (jikong) (JK02 protocol)
• Daly BMS
• JBD / Xiaoxiang BMS
• Victron SmartShunt

I tested the add-on on a Raspberry Pi 4 using Home Assistant Operating System.

Installation

• Go to your Home Assistant Add-on store and add this repository: https://github.com/fl4p/home-assistant-addons
• Install Batmon add-on
• Install, configure and start Mosquito MQTT broker (don't forget to configure the MQTT integration)

Configuration

The add-on can read multiple BMS at the same time. Add an entry for each device, such as:

- address: CC:44:8C:F7:AD:BB
  type: jk
  alias: battery1

address is the MAC address of the Bluetooth device. If you don't know the MAC address start the add-on, and you'll find a list of visible Bluetooth devices in the add-on log. Alternatively you can enter the device name here as displayed in the discovery list.

type can be jk, jbd, daly or victron.

With the alias field you can set the name as displayed in Home Assistant. Otherwise, the name as found in Bluetooth discovery is used.

If the device requires a PIN when pairing add pin: <device pin>

For verbose logs of particular BMS add debug: true.

• Set MQTT user and password. MQTT broker is usually core-mosquitto.
• concurrent_sampling tries to read all BMSs at the same time (instead of a serial read one after another). This can increase sampling rate for more timely-accurate data. Might cause Bluetooth connection issues if keep_alive is disabled.
• keep_alive will never close the bluetooth connection. Use for higher sampling rate. You will not be able to connect to the BMS from your phone anymore while the add-on is running.
• sample_period is the time in seconds to wait between BMS reads. Small periods generate more data points per time.
• invert_currents changes the sign of the current. Normally it is positive during discharge, inverted its negative.

Known Issues

• After a long-lasting bluetooth connection is lost both Daly and JBD dongles occasionally refuse to accept new connections and disappear from bluetooth discovery. Remove wires from the dongle and reconnect for a restart.
• Raspberry PI's bluetooth can be buggy. If you experience errors and timeouts try to install an external Bluetooth dongle.
• Pairing a Victron using a PIN doesn't work properly

TODO

• use the new Bluetooth integration since HA 2022.8 https://www.home-assistant.io/integrations/bluetooth/

Stand-alone

You can run the add-on outside of Home Assistant (e.g. on a remote RPI sending MQTT data of WiFI). See doc/Standalone.md

References

• dalybms: similar add-on
• JK-BMS: similar add-on using ESP-Home (needs extra hardware)
• Daly_RS485_UART_Protocol.pdf
• JK-bms esphome
• JK02 protocol