Update to driver version 10.1.2.94 or newer (released April 2021). 6.3 Missing “Battery Charge Threshold” after sleep Cause: EC reset on resume does not re-apply registry limit.

Windows Update replaced Lenovo ACPI driver with generic Microsoft ACPI driver.

Get-WinEvent -LogName "System" | Where-Object $_.ProviderName -eq "LenovoAcpi" Critical events to watch: Event ID 5 (EC communication timeout), Event ID 12 (Battery method not found).

pnputil /enum-drivers | findstr "acpivhd" pnputil /delete-driver oemXX.inf /uninstall # Then reinstall from Lenovo package Applies to: Early 2020 drivers on Windows 10 2004+.

Set-ItemProperty -Path "HKLM:\SOFTWARE\Lenovo\PowerMgmt" -Name "ChargeStartControl" -Value 1 Set-ItemProperty -Path "HKLM:\SOFTWARE\Lenovo\PowerMgmt" -Name "ChargeStopControl" -Value 1 # Restart LenovoAcpi service Restart-Service LenovoAcpi -Force Benchmarks on Lenovo X1 Carbon Gen 9 (Windows 10 22H2 64-bit):

Improptu D3cold transition on PCI root port.

*Due to enabled battery conservation mode and thermal throttling coordination.

| Model Series | Hardware ID | Driver file | |--------------|-------------|--------------| | ThinkPad T490/X1C7 | ACPI\LEN0268 | acpivhd.sys | | Legion Y540 | ACPI\VPC2004 | acpilik.sys | | Yoga C940 | ACPI\LEN0271 | acpivpc.sys |