LBM — Lenovo Battery Manager

Archive password: github.com

Download lbm.7z from the latest release

Extract the archive using password github.com. The release is distributed as a password-protected 7z archive; lbm.exe is not published as a raw GitHub asset.

LBM is a native x64 utility for configuring Lenovo battery charge thresholds on Windows. One executable provides two front ends over the same implementation: a command-line interface and a Win32 graphical interface.

The current release binary is 17,408 bytes (17.00 KiB). It is written in MASM x64, linked with /NODEFAULTLIB, and has no C runtime, .NET, Visual C++ Redistributable, Lenovo user-mode DLL, or Lenovo Vantage dependency.

LBM is not independent of the Lenovo kernel driver. Immediate threshold changes are sent to the device exposed by IBMPmDrv; the required Lenovo driver stack is documented under Requirements.

Download

• Archive: lbm.7z
• Password: github.com

Extract lbm.exe from the archive and run it directly. No installer is required. The executable contains both the CLI and GUI and requests Administrator privileges when a write operation requires elevation.

Interface

GUI

Run lbm.exe without arguments or use:

lbm.exe
lbm.exe --gui
lbm.exe -g

The GUI exposes the start and stop thresholds, the threshold enable state, an Apply action, and a Disable action. It uses the native Win32 controls and DWM APIs, including DPI awareness and the Windows 11 Mica backdrop where available.

CLI

lbm.exe
lbm.exe --status
lbm.exe -s
lbm.exe --set 75 80
lbm.exe --disable
lbm.exe --help

Command	Operation
--status, -s	Read and display the current battery configuration
--set <start> <stop>	Enable thresholds and apply both percentages
--disable	Disable threshold mode and return to automatic charging
--gui, -g	Open the graphical interface
--help, -h	Display command-line usage
no arguments	Open the graphical interface

Percentages must be in the range 0..100, with start < stop. GUI and CLI call the same Lbm_SetBatteryThresholds routine. Disabling through either front end writes 100/100, clears both control flags, and selects automatic charging mode in the driver.

Requirements

• x64 Windows 10 or Windows 11
• a compatible Lenovo system and battery firmware
• Administrator privileges for changing thresholds
• Lenovo PM Device driver package (ibmpmdrv.inf)
• the IBMPMDRV/PMDRVS kernel-driver stack, including ibmpmdrv.sys and pmdrvs.sys
• the \\.\IBMPmDrv device interface
• the Lenovo Power and Battery configuration installed by powermgr.inf, which provides the PWRMGRV registry data consumed by this version of LBM

The Microsoft Store Lenovo Vantage application is not required. The LenovoVantageService user-mode service is also not part of the LBM execution path. This was verified by stopping that service, applying two threshold pairs, and reading both values back from the Lenovo driver before restarting the service.

Do not remove the Lenovo PM Device or Lenovo Power and Battery driver packages. Removing Vantage is different from removing the kernel interface used to reach the embedded controller.

Implementation

LBM maintains the configuration in Lenovo's registry schema and applies it to the driver immediately. A threshold update follows this sequence:

1. Enumerate HKLM\SOFTWARE\WOW6432Node\Lenovo\PWRMGRV\ConfKeys\Data and select the battery subkey containing ChargeStartPercentage.
2. Write ChargeStartPercentage, ChargeStopPercentage, ChargeStartControl, and ChargeStopControl.
3. Open \\.\IBMPmDrv with CreateFileW.
4. Select threshold or automatic mode with DeviceIoControl.
5. In threshold mode, send the stop percentage followed by the start percentage.
6. Broadcast WM_SETTINGCHANGE for compatibility with installed Lenovo user-mode components.

The driver protocol used by the current x64 implementation is:

Operation	IOCTL	DWORD payload
Select automatic mode	0x22261C	0x00000000
Select battery 1 threshold mode	0x22261C	0x00000101
Set start threshold	0x222630	`0x00000100
Set stop threshold	0x222638	`0x00000100

Each call uses a four-byte input and a four-byte driver result. No Lenovo user-mode bridge DLL is loaded by LBM.

Binary properties

Property	Value
Architecture	AMD64 / x64
Source language	MASM x64
Entry point	mainCRTStartup
PE subsystem	Windows GUI
Current size	17,408 bytes / 17.00 KiB
C runtime	None
Default libraries	Disabled with /NODEFAULTLIB
Lenovo user-mode DLLs	None
Configuration front ends	CLI and GUI in one PE image

The PE imports only Windows system libraries:

KERNEL32.dll
USER32.dll
GDI32.dll
ADVAPI32.dll
SHELL32.dll
COMCTL32.dll
dwmapi.dll

These imports implement process startup, registry access, the console adapter, the Win32 GUI, UAC relaunch, common controls, and DWM integration. Battery control itself is performed through the Lenovo kernel device handle.

Building

Required tools:

• Visual Studio 2022/2026 or Build Tools with ml64.exe and link.exe
• Windows 10/11 SDK with rc.exe
• PowerShell

Build from the repository root:

.\build.ps1

Output:

bin\lbm.exe

The build script compiles resources, assembles every module, links a release PE with no default libraries, and removes intermediate objects from its temporary directory.

Equivalent linker characteristics include:

/ENTRY:mainCRTStartup
/SUBSYSTEM:WINDOWS
/NODEFAULTLIB
/MACHINE:X64
/OPT:REF
/OPT:ICF
/DYNAMICBASE
/HIGHENTROPYVA
/NXCOMPAT

Project layout

lbm/
├── src/
│   ├── main.asm       Zero-CRT entry point and CLI dispatch
│   ├── lbm_api.asm    Registry access and Lenovo driver IOCTL path
│   ├── window.asm     Native Win32 GUI
│   ├── uac.asm        Administrator detection and elevation
│   ├── nudge.asm      Console-output synchronization helper
│   └── consts.inc     Win32 constants, IOCTLs, and structures
├── res/
│   ├── resource.rc    Version and manifest resources
│   └── lbm.manifest   UAC, DPI, and Common Controls v6 manifest
├── images/
│   └── lbm.jpg        Native GUI screenshot
├── build.ps1          MASM x64 release build
└── LICENSE.md         MIT License

Scope and limitations

• LBM implements a Lenovo-specific protocol. It is not a generic battery tool for other manufacturers.
• The protocol was verified on the author's ThinkPad T14 driver stack. Other Lenovo generations can expose different devices, registry layouts, battery indexes, or firmware rules.
• Firmware remains authoritative. For example, a battery already above the stop threshold does not begin a new charging cycle until its state satisfies the controller's start conditions.
• Direct IOCTL success confirms that the driver accepted the request; the embedded controller still decides the physical charging transition.
• Removing or replacing the Lenovo PM driver makes the immediate-apply path unavailable.

License

MIT License — see LICENSE.md.

• Author: Marek Wesołowski (WESMAR)
• Contact: marek@wesolowski.eu.org
• Website: https://kvc.pl
• GitHub: https://github.com/wesmar/lbm