Basic NUT configuration for Green Cell UPS and Home Assistant integration

Green Cell PowerProof 600VA 480W

Prerequisites

• Linux on a device connected to LAN (Ubuntu 20.04 Server in this case)
• GreenCell UPS with the USB cable

NUT integration provides a good number of entities to use, like charge level or status

System configuration

Long story short, step by step:

Network UPS Tools official documentation: here

1. apt-get install nut
2. Take a look at lsusb
Mine device is recognized as ID 0001:0000 Fry's Electronics MEC0003
3. Edit config file: vi /etc/nut/ups.conf

4. Run upsdrvctl start

5. Edit vi /etc/nut/upsd.conf

6. Start the NUT server by running service nut-server start then go for upsc your_ups_name_here@localhost
As a result, you should get something similar to the following output:

7. The next step is to configure remote access.
Edit vi /etc/nut/upsd.users

8. Reload config upsd -c reload and then restart the driver upsdrvctl start just to be sure all is set

Home Assistant part

Go to the Integrations page. Your NUT server should be already discovered automatically. If not, search for NUT integration and follow the simple wizard. In both scenarios, you’ll have to type the username and password that you’ve just configured on the server. When manually adding the integration also IP address will be necessary.

NUT on the Integrations page

There is a lot of entities available like:

Battery Voltage
Beeper Status
Input Line Frequency
Input Voltage
Load
Load Restart Delay
Output Voltage
Status Data
UPS Shutdown Delay
UPS Type
Charge
Status

The number of monitored entities can be adjusted with the NUT integration wizard. Some devices don’t report all states or need additional configuration server-side. Like my device was missing battery low/high values and was unable to determine battery charge percentage, so I have to update ups.conf with correct values based on battery characteristics.