Add fans and battery sensor to systemmonitor

[gjohansson-ST]

Breaking change

Proposed change

Add sensors for fan rpm and battery to systemmonitor

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: Add more sensors to System monitor home-assistant.io#40578
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[Copilot]

Pull Request Overview

This PR adds fan RPM and battery sensor capabilities to the systemmonitor integration, expanding its monitoring capabilities beyond existing disk, memory, and temperature sensors.

Key changes:

• Adds fan RPM sensors that read from psutil.sensors_fans() to display individual fan speeds
• Adds a battery sensor that reads from psutil.sensors_battery() to show battery percentage
• Implements proper sensor descriptions, icons, and string translations for the new sensor types

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/components/systemmonitor/conftest.py	Adds mock data for fan and battery sensors in test fixtures
homeassistant/components/systemmonitor/util.py	Implements read_fan_rpm() utility function to parse fan sensor data
homeassistant/components/systemmonitor/strings.json	Adds translation keys for battery and fan RPM sensor names
homeassistant/components/systemmonitor/sensor.py	Defines sensor descriptions and setup logic for battery and fan RPM sensors
homeassistant/components/systemmonitor/icons.json	Adds icons for battery and fan RPM sensors
homeassistant/components/systemmonitor/coordinator.py	Updates data coordinator to fetch fan and battery data from psutil

[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[emontnemery]

LGTM, thanks @gjohansson-ST 👍

stale