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This guide will help you get KVantage up and running on your Lenovo laptop in just a few minutes.

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Prerequisites

Before you begin, make sure you have:
  • A Lenovo laptop running Linux
  • Java Runtime Environment (JRE) installed
  • The acpi_call kernel module loaded
Not sure if you meet the requirements? Check the System Requirements page for detailed information.

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Quick Start Steps

1

Download KVantage

Download the latest version:
wget https://github.com/kosail/KVantage/releases/download/Release_v2.1.0/com.korealm.kvantage-linux-x64-2.1.0-release.jar
Or download manually from the releases page.
2

Install Java (if needed)

Check if Java is installed:
java -version
If not installed, use your package manager:
sudo apt install default-jre
3

Launch KVantage

Run the JAR file:
java -jar com.korealm.kvantage-linux-x64-2.1.0-release.jar
Never run KVantage with sudo or as root. The application must run as a regular user. Root access is handled automatically by the backend service.
4

Complete first-time setup

On first launch, KVantage will display an installation dialog:
  • Click “Okay” to install KVantage to ~/.local/bin/ and create a desktop entry
  • Click “No” to use KVantage as a portable application
  • Click “No, and don’t ask me again” to use portably and suppress future prompts
The installer will:
  • Copy the JAR to your local bin directory
  • Create a desktop entry for easy launching
  • Extract the application icon
  • Allow launching from your application menu
5

Authenticate the backend service

After installation, KVantage will start its backend service (kvand) which requires root access.You’ll see your system’s password prompt (polkit dialog, pkexec, or terminal sudo prompt).
This password prompt appears once per session. The backend needs root access to read/write ACPI values at /proc/acpi/call. The GUI itself never runs with elevated privileges.
Enter your password to continue.

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Understanding the KVantage Interface

Once KVantage launches successfully, you’ll see the main window with several sections:

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Performance Profile

The top section displays your current performance profile with three options:
  • Power Saving - Optimizes for battery life
  • Intelligent Cooling - Balanced performance and thermals
  • Performance - Maximum performance mode
Click any profile to switch immediately.

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Battery Threshold (Conservation Mode)

This feature limits your battery charge to 80% to improve battery lifespan:
  • Toggle the switch to Enable or disable battery conservation
  • Useful for laptops that stay plugged in most of the time
The battery threshold is set to 80% and cannot be customized in most Lenovo laptop models. Custom thresholds are a premium feature available only on certain high-end models.

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Rapid Charge

Enable or disable rapid charging for your battery:
  • Enabled - Charges faster (may generate more heat)
  • Disabled - Slower, gentler charging (better for battery health)

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Battery Information

If enabled in settings, you’ll see:
  • Battery name/model
  • Remaining battery lifespan percentage
  • Current charge percentage icon

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Settings Panel

Click the settings button (gear icon) to access:
  • Dark mode toggle
  • Animated background toggle
  • Show battery life toggle
  • Theme selection (multiple color schemes available)
  • Language (auto-detected from system locale)

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Your First Actions

Here are some common tasks to get started:

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Enable Battery Conservation Mode

If your laptop is usually plugged in:
  1. Locate the Battery Threshold section
  2. Toggle the switch to Enable
  3. Your battery will now stop charging at 80%
This feature significantly extends battery lifespan for laptops that remain plugged in for extended periods.

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Switch Performance Profile

To change your laptop’s performance mode:
  1. Find the Performance Profile section at the top
  2. Click your desired profile:
    • Power Saving for extended battery life
    • Intelligent Cooling for balanced performance
    • Performance when you need maximum power
  3. The change applies immediately

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Customize the Theme

  1. Click the Settings button (gear icon)
  2. Scroll to Themes
  3. Select from multiple color schemes:
    • Whispering Sea (default)
    • And several other Material UI-inspired themes
  4. Toggle Dark mode for your preference
  5. Enable Animated Background for visual flair

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Understanding Root Access

KVantage has a unique architecture for handling root permissions:
  • GUI (Frontend): Runs as your regular user - never requires or uses root
  • Backend (kvand): A small daemon that handles ACPI operations - requires root

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How it works:

  1. When you launch KVantage, the GUI starts as your user
  2. The GUI extracts and launches the kvand backend service
  3. The backend requests root access once using your system’s authentication
  4. All ACPI read/write operations are handled by the backend
  5. The GUI communicates with the backend over a local pipe

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Security benefits:

  • The GUI never runs with elevated privileges
  • Your window manager and compositor remain secure
  • Only the minimal backend service requires root
  • Root access is requested through standard system dialogs (polkit/pkexec)
If you try to run KVantage with sudo, it will immediately exit with an error message. This is a safety feature to prevent running the GUI with unnecessary privileges.

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Next Steps

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Troubleshooting Quick Issues

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”Backend service failed to start”

The acpi_call module may not be loaded: 
sudo modprobe acpi_call
Verify it’s loaded: 
lsmod | grep acpi_call
ls -l /proc/acpi/call

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“App must never be started as root”

You ran KVantage with sudo. Run it as your regular user: 
# Remove sudo
java -jar com.korealm.kvantage-linux-x64-2.1.0-release.jar

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Password prompt doesn’t appear

Ensure you have a polkit authentication agent installed: 
sudo apt install gnome-polkit

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