Integrating my ML2440 Solar Controller with Home Assistant Using renogy-ha and a Bluetooth Proxy

In this post, I’ll share how I integrated my Renogy ML2440 solar charge controller into Home Assistant using the fantastic renogy–ha integration. With the help of a simple Bluetooth proxy, I now have full visibility into my solar setup—completely local and cloud-free.

Whether you’re running a similar off-grid solar system or just want deeper insight into your charge controller’s performance, this guide will walk you through the hardware, software, and my own experiences.

My Setup

Here’s a quick rundown of my hardware:

• Solar Controller: ML2440
• Bluetooth Adapter: Renogy BT-1 Bluetooth Module (connected to the controller)
• Bluetooth Proxy: Athom Atom Lite running ESPHome as a Bluetooth proxy
• Home Assistant Integration: renogy-ha

The setup works flawlessly and has been rock-solid in my Home Assistant ecosystem.

Why I Chose renogy-ha

The renogy-ha integration provides direct communication between Home Assistant and the Renogy BT-1 module over Bluetooth. This lets you pull in all the key metrics from your charge controller, including:

• PV (solar panel) voltage and current
• Battery voltage, current, and state of charge (SOC)
• Controller temperature
• Charging mode and load status

It’s 100% local—no internet connection or third-party app required once it’s set up.

Using the Athom Atom Lite as a Bluetooth Proxy

Because my Home Assistant server isn’t close enough to the Renogy controller to get a reliable Bluetooth signal, I added a Bluetooth proxy using an Athom Atom Lite device. This small, ESP32-based device is perfect for the job.

Here’s my actual ESPHome YAML configuration for it:

substitutions:
  name: m5stack-atom-lite-94cdf0
  friendly_name: Bluetooth Proxy 94cdf0

packages:
  esphome.bluetooth-proxy: github://esphome/bluetooth-proxies/m5stack/m5stack-atom-lite.yaml@main

esphome:
  name: ${name}
  name_add_mac_suffix: false
  friendly_name: ${friendly_name}

api:
  encryption:
    key: xxxxxxxxxxxxxxxxx

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

This uses the official ESPHome Bluetooth proxy package for the M5Stack Atom Lite, and it couldn’t be easier to set up. The Athom Atom Lite is a great choice thanks to its compact size, good performance, and ease of flashing with ESPHome.

Installing renogy-ha

To install the renogy-ha integration, follow the instructions from the official GitHub page. As of now, here’s a quick summary:

1. Install via HACS (Highly Recommended):
   • In Home Assistant, go to HACS → Integrations → Custom Repositories.
   • Add https://github.com/IAmTheMitchell/renogy-ha as a custom repository (category: Integration).
   • Search for Renogy in HACS and install it.
2. Manual Installation (if not using HACS):
   • Download the latest release from GitHub.
   • Place the renogy folder inside your Home Assistant custom_components directory.

After installation, restart Home Assistant to apply the changes.

Setting Up in Home Assistant

Once Home Assistant restarts:

1. Go to Settings → Devices & Services.
2. Click Add Integration.
3. Search for Renogy.

The integration will scan for available Renogy Bluetooth devices (via your proxy if needed). Once your BT-1 device appears, select it to finish the setup.

What Sensors Appear

After setup, Home Assistant will populate several sensors for your controller. These will be prefixed with a unique ID based on your BT-1 module. For example, my sensors look like this:

• sensor.bt_th_19f3f8e8_battery_soc
• sensor.bt_th_19f3f8e8_pv_charging_current
• sensor.bt_th_19f3f8e8_pv_voltage
• sensor.bt_th_19f3f8e8_controller_temperature
• sensor.bt_th_19f3f8e8_battery_voltage
• sensor.bt_th_19f3f8e8_charging_mode

(The 19f3f8e8 part will be specific to your device.)

These sensors give you full visibility into your solar system’s status and performance. You can now build automations, alerts, and dashboards based on live solar data.

My Experience So Far

I’ve been running this setup for a while now, and it’s been completely reliable. The Bluetooth proxy with the Athom Atom Lite works seamlessly—no dropouts or signal issues—and renogy-ha pulls in all the data I need.

Having this level of insight into my solar system inside Home Assistant has made a huge difference, especially for tracking battery health, charging trends, and system performance over time.

Final Thoughts

If you have a Renogy controller with a BT-1 module and you’re using Home Assistant, I highly recommend giving renogy-ha a try. With the addition of a simple ESPHome Bluetooth proxy like the Athom Atom Lite, you can build a completely local, reliable solar monitoring setup.

Have questions or want to share your own setup? Drop a comment below—I’d love to hear about it!