Lenovo Power Tray

A lightweight Windows system-tray app for Lenovo ThinkPad laptops (built and tested on an X1 Yoga Gen 7) that toggles two power features without opening the slow Lenovo Vantage app:

• Smart Charge — battery charge threshold, via the Lenovo Power Manager local-RPC interface (the same one Lenovo Vantage uses), through a small native bridge (LenPower.dll)
• Smart Standby — Modern Standby scheduling, via the LenovoSmartStandby Windows service

Left-click the tray icon for a battery dashboard (arc gauge with live % and charge-rate, threshold tick markers, adjustable start/stop sliders); right-click for quick toggles plus a launch-at-startup option. The tray icon itself shows a live battery-level arc, colour-coded green/orange/red.

⚠️ 100% vibe coded

This project was written entirely by an AI assistant ("vibe coded") through natural-language prompting — no line was hand-authored by a human. Treat it accordingly: it works on the author's machine, but it drives Lenovo's power-management RPC interface and a Windows service and comes with no warranty. Read the code before running it elevated on your own hardware.

Install

winget (recommended):

winget install 0z00z0.LenovoPowerTray
winget upgrade 0z00z0.LenovoPowerTray   # update later

Or grab LenovoPowerTray-Setup.exe from the latest release and run it. The installer is per-user — no admin needed to install — and offers two options:

• Run at startup — auto-starts the app at sign-in. Ticking it asks for elevation once, to register a prompt-free elevated logon task.
• Auto update in background — a logon task that silently runs winget upgrade after each sign-in, so the app keeps itself current. Needs no elevation, and only works once the package is available from a winget source (see installer/README.md).

The app itself shows a UAC prompt when it launches, since changing the charge threshold / standby service requires administrator rights.

Requirements

• Windows 10 (1809+) / Windows 11 on a Lenovo ThinkPad
• Administrator rights — both features require elevation (the app manifest declares requireAdministrator)

Smart Charge prerequisite — Lenovo Power Management Driver

Smart Charge talks directly to the Lenovo Power Management Driver (Windows service PWMGR, "Lenovo Power and Battery") — the same service Lenovo Vantage uses under the hood.

You do not need Lenovo Vantage. You do need the driver.

It ships as part of the ThinkPad hardware driver package. If your laptop originally shipped with Windows (or has had a full driver installation) it is almost certainly already present.

To check — run in an elevated PowerShell:

Get-Service -Name PWMGR -ErrorAction SilentlyContinue

If the service appears (Running or Stopped), Smart Charge will work. If nothing is returned, install the driver:

1. Go to your model's driver page on Lenovo Support (search your model name / serial number, or use PC Support Auto-Detect).
2. Select Drivers & Software → category Power Management.
3. Download and run "Power Management Driver for Windows 10 and 11 (64-bit)".

If the driver is absent, Smart Charge shows as Unavailable in the tray and dashboard — the rest of the app (Smart Standby, auto-start, battery gauge) works fine without it.

Build prerequisites

• .NET 10 SDK
• A C++ toolset (Visual Studio / Build Tools with "Desktop development with C++") to build the native Smart Charge bridge (native/) — only needed once

Build from source

# 1. Build the native Smart Charge bridge (LenPower.dll). One-time, needs the C++ toolset.
#    build.cmd locates MSVC + MIDL automatically (incl. VS 2026 Insiders).
cd native
.\build.cmd
cd ..

# 2. Build the app (Release output is Authenticode-signed if a cert is set up — see USAGE.md).
#    The csproj copies native\LenPower.dll next to the executable.
dotnet build -c Release

# 3. Run elevated
dotnet run
# or right-click the compiled LenovoTray.exe → "Run as administrator"

Smart Standby, the dashboard, and auto-start work without the native bridge. If LenPower.dll is missing, Smart Charge simply shows as Unavailable rather than breaking the app.

A UAC prompt appears on first launch. Enable Launch at startup from the right-click menu to auto-start prompt-free on subsequent boots (via a Task Scheduler logon task).

See USAGE.md for full usage, code-signing, troubleshooting, and architecture notes.

Building the installer

The per-user installer is built with Inno Setup and distributed via winget. See installer/README.md for the full release workflow:

winget install JRSoftware.InnoSetup     # one-time
cd installer
.\build-installer.ps1 -Version 1.0.0    # → installer\Output\LenovoPowerTray-Setup.exe

External libraries

The app targets the Microsoft stack (.NET, Windows App SDK / WinUI 3, System.* runtime packages). The only non-Microsoft dependencies are:

Library	Author	Purpose	License
H.NotifyIcon.WinUI	HavenDV	System-tray icon + native context menu for WinUI 3	MIT
TaskScheduler	David Hall	Managed wrapper over the Windows Task Scheduler API (auto-start)	MIT

Credits & acknowledgements

Smart Charge is the hard part: ThinkPad firmware does not expose the battery charge threshold through WMI, so it has to be driven over the Lenovo Power Manager's local-RPC interface — the same one Lenovo Vantage uses.

• LenPwrCtl by alandau (MIT) — the Power Manager RPC interface in native/pwrmgr.idl (endpoint, context handles, and the LpcGetChargeThreshold / LpcSetChargeThreshold procedure layout) was reverse-engineered by this project and is reused here under its MIT license. This app would not be possible without it. Huge thanks. 🙏

The native/ bridge (lenpower.c) is a thin wrapper that exposes two flat exports over that interface for the managed app to P/Invoke; the interface definition itself is alandau's work.

Tooling: the installer is built with Inno Setup by Jordan Russell & Martijn Laan (free, with attribution under its license), and distributed via winget (Microsoft, MIT).

License

MIT © Zero Zero Software (0z0.xyz) — you are free to use, modify, fork, and redistribute, including commercially, provided you keep the copyright and license notice. See LICENSE for the full text.