I needed a VBA procedure to retrieve the system's current battery charge level and charging status.
I was surprised not to find anything on Stack Overflow, and I eventually figured it out, so I'll share the code here as a Q+A.
Private Declare PtrSafe Function GetSystemPowerStatus Lib "kernel32" (lpSystemPowerStatus As SYSTEM_POWER_STATUS) As LongPtr
Private Type SYSTEM_POWER_STATUS
ACLineStatus As Byte
BatteryFlag As Byte
BatteryLifePercent As Byte
SystemStatusFlag As Byte
BatteryLifeTime As Long
BatteryFullLifeTime As Long
End Type
Public Sub getBatteryStatus() 'batt info to immediate window
Dim SPS As SYSTEM_POWER_STATUS
GetSystemPowerStatus SPS 'get system batt power status
With SPS
Debug.Print "Battery Life: ", ;
Select Case .BatteryLifePercent
Case 255: Debug.Print "Unknown"
Case Else: Debug.Print .BatteryLifePercent & "%"
End Select
Debug.Print "Battery Life Time: ", ;
Select Case .BatteryLifeTime
Case -1: Debug.Print "Charging"
Case Else
Debug.Print Int(.BatteryLifeTime / 60) & "min / ";
Select Case .BatteryFullLifeTime
Case -1
If .BatteryLifePercent = 0 Then
Debug.Print "Unknown"
Else 'estimate FullLifeTime:
Debug.Print "~" & Int(.BatteryLifeTime / .BatteryLifePercent * 5 / 3) & "min"
End If
Case Else
Debug.Print .BatteryFullLifeTime & "sec"
End Select
End Select
Debug.Print "AC power status: ", ;
Select Case .ACLineStatus 'show some information
Case 0: Debug.Print "Offline"
Case 1: Debug.Print "OnLine"
Case Else: Debug.Print "Unknown"
End Select
Debug.Print "Battery charge status: ", ;
Select Case .BatteryFlag
Case 0: Debug.Print "Not Charging (33-66%)"
Case 1: Debug.Print "High (>66%)"
Case 2: Debug.Print "Low (<33%)"
Case 4: Debug.Print "Critical (<5%)"
Case 8: Debug.Print "Charging"
Case 1 + 8: Debug.Print "High (>66%)- Charging"
Case 2 + 8: Debug.Print "Low (<33%) - Charging"
Case 4 + 8: Debug.Print "Critical (<5%) - Charging"
Case 128: Debug.Print "No System Battery"
Case 255: Debug.Print "Unknown Status"
End Select
Debug.Print "Battery saver: ", ;
Select Case .SystemStatusFlag
Case 0: Debug.Print "Off"
Case 1: Debug.Print "On (Save energy where possible)" 'Windows 10 only
End Select
End With
End Sub