Battery info from win32 api

battery.cs

using System;
using System.IO;
using Microsoft.Win32.SafeHandles;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            BatteryInformation cap = BatteryInfo.GetBatteryInformation();
       } 
    }

    public class BatteryInformation
    {
        public uint CurrentCapacity { get; set; }
        public int DesignedMaxCapacity { get; set; }
        public int FullChargeCapacity { get; set; }
        public uint Voltage { get; set; }
        public int DischargeRate { get; set; }
    }

    public static class BatteryInfo
    {

        public static BatteryInformation GetBatteryInformation()
        {
            IntPtr deviceDataPointer = IntPtr.Zero;
            IntPtr queryInfoPointer = IntPtr.Zero;
            IntPtr batteryInfoPointer = IntPtr.Zero;
            IntPtr batteryWaitStatusPointer = IntPtr.Zero;
            IntPtr batteryStatusPointer = IntPtr.Zero;
            try
            {
                IntPtr deviceHandle = SetupDiGetClassDevs(
                Win32.GUID_DEVCLASS_BATTERY, Win32.DEVICE_GET_CLASS_FLAGS.DIGCF_PRESENT | Win32.DEVICE_GET_CLASS_FLAGS.DIGCF_DEVICEINTERFACE);

                Win32.SP_DEVICE_INTERFACE_DATA deviceInterfaceData = new Win32.SP_DEVICE_INTERFACE_DATA();
                deviceInterfaceData.CbSize = Marshal.SizeOf(deviceInterfaceData);

                SetupDiEnumDeviceInterfaces(deviceHandle, Win32.GUID_DEVCLASS_BATTERY, 0, ref deviceInterfaceData);

                deviceDataPointer = Marshal.AllocHGlobal(Win32.DEVICE_INTERFACE_BUFFER_SIZE);
                //Win32.SP_DEVICE_INTERFACE_DETAIL_DATA deviceDetailData =
                //    (Win32.SP_DEVICE_INTERFACE_DETAIL_DATA)Marshal.PtrToStructure(deviceDataPointer, typeof(Win32.SP_DEVICE_INTERFACE_DETAIL_DATA));

                //toggle these two and see if naything changes... ^^^^^^^^^^^^
                Win32.SP_DEVICE_INTERFACE_DETAIL_DATA deviceDetailData = new Win32.SP_DEVICE_INTERFACE_DETAIL_DATA();
                deviceDetailData.CbSize = (IntPtr.Size == 8) ? 8 : 4 + Marshal.SystemDefaultCharSize;

                SetupDiGetDeviceInterfaceDetail(deviceHandle, ref deviceInterfaceData, ref deviceDetailData, Win32.DEVICE_INTERFACE_BUFFER_SIZE);

                IntPtr batteryHandle = CreateFile(deviceDetailData.DevicePath, FileAccess.ReadWrite, FileShare.ReadWrite, FileMode.Open, Win32.FILE_ATTRIBUTES.Normal);

                Win32.BATTERY_QUERY_INFORMATION queryInformation = new Win32.BATTERY_QUERY_INFORMATION();

                DeviceIoControl(batteryHandle, Win32.IOCTL_BATTERY_QUERY_TAG, ref queryInformation.BatteryTag);

                Win32.BATTERY_INFORMATION batteryInformation = new Win32.BATTERY_INFORMATION();
                queryInformation.InformationLevel = Win32.BATTERY_QUERY_INFORMATION_LEVEL.BatteryInformation;

                int queryInfoSize = Marshal.SizeOf(queryInformation);
                int batteryInfoSize = Marshal.SizeOf(batteryInformation);

                queryInfoPointer = Marshal.AllocHGlobal(queryInfoSize);
                Marshal.StructureToPtr(queryInformation, queryInfoPointer, false);

                batteryInfoPointer = Marshal.AllocHGlobal(batteryInfoSize);
                Marshal.StructureToPtr(batteryInformation, batteryInfoPointer, false);

                DeviceIoControl(batteryHandle, Win32.IOCTL_BATTERY_QUERY_INFORMATION, queryInfoPointer, queryInfoSize, batteryInfoPointer, batteryInfoSize);

                Win32.BATTERY_INFORMATION updatedBatteryInformation =
                    (Win32.BATTERY_INFORMATION)Marshal.PtrToStructure(batteryInfoPointer, typeof(Win32.BATTERY_INFORMATION));

                Win32.BATTERY_WAIT_STATUS batteryWaitStatus = new Win32.BATTERY_WAIT_STATUS();
                batteryWaitStatus.BatteryTag = queryInformation.BatteryTag;

                Win32.BATTERY_STATUS batteryStatus = new Win32.BATTERY_STATUS();

                int waitStatusSize = Marshal.SizeOf(batteryWaitStatus);
                int batteryStatusSize = Marshal.SizeOf(batteryStatus);

                batteryWaitStatusPointer = Marshal.AllocHGlobal(waitStatusSize);
                Marshal.StructureToPtr(batteryWaitStatus, batteryWaitStatusPointer, false);

                batteryStatusPointer = Marshal.AllocHGlobal(batteryStatusSize);
                Marshal.StructureToPtr(batteryStatus, batteryStatusPointer, false);

                DeviceIoControl(batteryHandle, Win32.IOCTL_BATTERY_QUERY_STATUS, batteryWaitStatusPointer, waitStatusSize, batteryStatusPointer, batteryStatusSize);

                Win32.BATTERY_STATUS updatedStatus =
                    (Win32.BATTERY_STATUS)Marshal.PtrToStructure(batteryStatusPointer, typeof(Win32.BATTERY_STATUS));

                Win32.SetupDiDestroyDeviceInfoList(deviceHandle);

                return new BatteryInformation()
                {
                    DesignedMaxCapacity = updatedBatteryInformation.DesignedCapacity,
                    FullChargeCapacity = updatedBatteryInformation.FullChargedCapacity,
                    CurrentCapacity = updatedStatus.Capacity,
                    Voltage = updatedStatus.Voltage,
                    DischargeRate = updatedStatus.Rate
                };
                
            }
            finally
            {
                Marshal.FreeHGlobal(deviceDataPointer);
                Marshal.FreeHGlobal(queryInfoPointer);
                Marshal.FreeHGlobal(batteryInfoPointer);
                Marshal.FreeHGlobal(batteryStatusPointer);
                Marshal.FreeHGlobal(batteryWaitStatusPointer);
            }
        }



        private static bool DeviceIoControl(IntPtr deviceHandle, uint controlCode, ref uint output)
        {
            uint bytesReturned;
            uint junkInput = 0;
            bool retval = Win32.DeviceIoControl(
                deviceHandle, controlCode, ref junkInput, 0, ref output, (uint)Marshal.SizeOf(output), out bytesReturned, IntPtr.Zero);

            if (!retval)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    throw Marshal.GetExceptionForHR(errorCode);
                else
                    throw new Exception(
                        "DeviceIoControl call failed but Win32 didn't catch an error.");
            }

            return retval;
        }

        private static bool DeviceIoControl(
            IntPtr deviceHandle, uint controlCode, IntPtr input, int inputSize, IntPtr output, int outputSize)
        {
            uint bytesReturned;
            bool retval = Win32.DeviceIoControl(
                deviceHandle, controlCode, input, (uint)inputSize, output, (uint)outputSize, out bytesReturned, IntPtr.Zero);

            if (!retval)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    throw Marshal.GetExceptionForHR(errorCode);
                else
                    throw new Exception(
                        "DeviceIoControl call failed but Win32 didn't catch an error.");
            }

            return retval;
        }

        private static IntPtr SetupDiGetClassDevs(Guid guid, Win32.DEVICE_GET_CLASS_FLAGS flags)
        {
            IntPtr handle = Win32.SetupDiGetClassDevs(ref guid, null, IntPtr.Zero, flags);

            if (handle == IntPtr.Zero || handle.ToInt32() == -1)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    throw Marshal.GetExceptionForHR(errorCode);
                else
                    throw new Exception("SetupDiGetClassDev call returned a bad handle.");
            }
            return handle;
        }

        private static bool SetupDiEnumDeviceInterfaces(
            IntPtr deviceInfoSet, Guid guid, int memberIndex, ref Win32.SP_DEVICE_INTERFACE_DATA deviceInterfaceData)
        {
            bool retval = Win32.SetupDiEnumDeviceInterfaces(
                deviceInfoSet, IntPtr.Zero, ref guid, (uint)memberIndex, ref deviceInterfaceData);

            if (!retval)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                {
                    if (errorCode == 259)
                        throw new Exception("SetupDeviceInfoEnumerateDeviceInterfaces ran out of batteries to enumerate.");

                    throw Marshal.GetExceptionForHR(errorCode);
                }
                else
                    throw new Exception(
                        "SetupDeviceInfoEnumerateDeviceInterfaces call failed but Win32 didn't catch an error.");
            }
            return retval;
        }

        private static bool SetupDiDestroyDeviceInfoList(IntPtr deviceInfoSet)
        {
            bool retval = Win32.SetupDiDestroyDeviceInfoList(deviceInfoSet);

            if (!retval)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    throw Marshal.GetExceptionForHR(errorCode);
                else
                    throw new Exception(
                        "SetupDiDestroyDeviceInfoList call failed but Win32 didn't catch an error.");
            }
            return retval;
        }

        private static bool SetupDiGetDeviceInterfaceDetail(
            IntPtr deviceInfoSet, ref Win32.SP_DEVICE_INTERFACE_DATA deviceInterfaceData, ref Win32.SP_DEVICE_INTERFACE_DETAIL_DATA deviceInterfaceDetailData, int deviceInterfaceDetailSize)
        {
            //int tmpSize = Marshal.SizeOf(deviceInterfaceDetailData);
            uint reqSize;
            bool retval = Win32.SetupDiGetDeviceInterfaceDetail(
                deviceInfoSet, ref deviceInterfaceData, ref deviceInterfaceDetailData, (uint)deviceInterfaceDetailSize, out reqSize, IntPtr.Zero);

            if (!retval)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    throw Marshal.GetExceptionForHR(errorCode);
                else
                    throw new Exception(
                        "SetupDiGetDeviceInterfaceDetail call failed but Win32 didn't catch an error.");
            }
            return retval;
        }

        private static IntPtr CreateFile(
            string filename, FileAccess access, FileShare shareMode, FileMode creation, Win32.FILE_ATTRIBUTES flags)
        {
            IntPtr handle = Win32.CreateFile(
                filename, access, shareMode, IntPtr.Zero, creation, flags, IntPtr.Zero);

            if (handle == IntPtr.Zero || handle.ToInt32() == -1)
            {
                int errorCode = Marshal.GetLastWin32Error();
                if (errorCode != 0)
                    Marshal.ThrowExceptionForHR(errorCode);
                else
                    throw new Exception(
                        "SetupDiGetDeviceInterfaceDetail call failed but Win32 didn't catch an error.");
            }
            return handle;
        }
    }

    internal static class Win32
    {
        internal static readonly Guid GUID_DEVCLASS_BATTERY = new Guid(0x72631E54, 0x78A4, 0x11D0, 0xBC, 0xF7, 0x00, 0xAA, 0x00, 0xB7, 0xB3, 0x2A);
        internal const uint IOCTL_BATTERY_QUERY_TAG = (0x00000029 << 16) | ((int)FileAccess.Read << 14) | (0x10 << 2) | (0);
        internal const uint IOCTL_BATTERY_QUERY_INFORMATION = (0x00000029 << 16) | ((int)FileAccess.Read << 14) | (0x11 << 2) | (0);
        internal const uint IOCTL_BATTERY_QUERY_STATUS = (0x00000029 << 16) | ((int)FileAccess.Read << 14) | (0x13 << 2) | (0);

        internal const int DEVICE_INTERFACE_BUFFER_SIZE = 120;


        [DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern IntPtr SetupDiGetClassDevs(
            ref Guid guid, 
            [MarshalAs(UnmanagedType.LPTStr)] string enumerator, 
            IntPtr hwnd, 
            DEVICE_GET_CLASS_FLAGS flags);

        [DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool SetupDiDestroyDeviceInfoList(IntPtr deviceInfoSet);

        [DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool SetupDiEnumDeviceInterfaces(
            IntPtr hdevInfo, 
            IntPtr devInfo, 
            ref Guid guid, 
            uint memberIndex, 
            ref SP_DEVICE_INTERFACE_DATA devInterfaceData);

        [DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool SetupDiGetDeviceInterfaceDetail(
            IntPtr hdevInfo,
            ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData,
            ref SP_DEVICE_INTERFACE_DETAIL_DATA deviceInterfaceDetailData,
            uint deviceInterfaceDetailDataSize,
            out uint requiredSize,
            IntPtr deviceInfoData);

        [DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
        internal static extern bool SetupDiGetDeviceInterfaceDetail(
            IntPtr hdevInfo,
            ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData,
            IntPtr deviceInterfaceDetailData,
            uint deviceInterfaceDetailDataSize,
            out uint requiredSize,
            IntPtr deviceInfoData);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        internal static extern IntPtr CreateFile(
            string filename, 
            [MarshalAs(UnmanagedType.U4)] FileAccess desiredAccess,
            [MarshalAs(UnmanagedType.U4)] FileShare shareMode, 
            IntPtr securityAttributes,
            [MarshalAs(UnmanagedType.U4)] FileMode creationDisposition, 
            [MarshalAs(UnmanagedType.U4)] FILE_ATTRIBUTES flags, 
            IntPtr template);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        internal static extern bool DeviceIoControl(
            IntPtr handle,
            uint controlCode,
            [In] IntPtr inBuffer,
            uint inBufferSize,
            [Out] IntPtr outBuffer,
            uint outBufferSize,
            out uint bytesReturned,
            IntPtr overlapped);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        internal static extern bool DeviceIoControl(
            IntPtr handle,
            uint controlCode,
            ref uint inBuffer,
            uint inBufferSize,
            ref uint outBuffer,
            uint outBufferSize,
            out uint bytesReturned,
            IntPtr overlapped);

        [Flags]
        internal enum DEVICE_GET_CLASS_FLAGS : uint
        {
            DIGCF_DEFAULT = 0x00000001,
            DIGCF_PRESENT = 0x00000002,
            DIGCF_ALLCLASSES = 0x00000004,
            DIGCF_PROFILE = 0x00000008,
            DIGCF_DEVICEINTERFACE = 0x00000010
        }

        [Flags]
        internal enum LOCAL_MEMORY_FLAGS
        {
            LMEM_FIXED = 0x0000,
            LMEM_MOVEABLE = 0x0002,
            LMEM_NOCOMPACT = 0x0010,
            LMEM_NODISCARD = 0x0020,
            LMEM_ZEROINIT = 0x0040,
            LMEM_MODIFY = 0x0080,
            LMEM_DISCARDABLE = 0x0F00,
            LMEM_VALID_FLAGS = 0x0F72,
            LMEM_INVALID_HANDLE = 0x8000,
            LHND = (LMEM_MOVEABLE | LMEM_ZEROINIT),
            LPTR = (LMEM_FIXED | LMEM_ZEROINIT),
            NONZEROLHND = (LMEM_MOVEABLE),
            NONZEROLPTR = (LMEM_FIXED)
        }

        [Flags]
        internal enum FILE_ATTRIBUTES : uint
        {
            Readonly = 0x00000001,
            Hidden = 0x00000002,
            System = 0x00000004,
            Directory = 0x00000010,
            Archive = 0x00000020,
            Device = 0x00000040,
            Normal = 0x00000080,
            Temporary = 0x00000100,
            SparseFile = 0x00000200,
            ReparsePoint = 0x00000400,
            Compressed = 0x00000800,
            Offline = 0x00001000,
            NotContentIndexed = 0x00002000,
            Encrypted = 0x00004000,
            Write_Through = 0x80000000,
            Overlapped = 0x40000000,
            NoBuffering = 0x20000000,
            RandomAccess = 0x10000000,
            SequentialScan = 0x08000000,
            DeleteOnClose = 0x04000000,
            BackupSemantics = 0x02000000,
            PosixSemantics = 0x01000000,
            OpenReparsePoint = 0x00200000,
            OpenNoRecall = 0x00100000,
            FirstPipeInstance = 0x00080000
        }

        internal enum BATTERY_QUERY_INFORMATION_LEVEL
        {
            BatteryInformation = 0,
            BatteryGranularityInformation = 1,
            BatteryTemperature = 2,
            BatteryEstimatedTime = 3,
            BatteryDeviceName = 4,
            BatteryManufactureDate = 5,
            BatteryManufactureName = 6,
            BatteryUniqueID = 7
        }

        [Flags]
        internal enum POWER_STATE : uint
        {
            BATTERY_POWER_ONLINE = 0x00000001,
            BATTERY_DISCHARGING = 0x00000002,
            BATTERY_CHARGING = 0x00000004,
            BATTERY_CRITICAL = 0x00000008
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct BATTERY_INFORMATION
        {
            public int Capabilities;
            public byte Technology;

            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
            public byte[] Reserved;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] Chemistry;

            public int DesignedCapacity;
            public int FullChargedCapacity;
            public int DefaultAlert1;
            public int DefaultAlert2;
            public int CriticalBias;
            public int CycleCount;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct SP_DEVICE_INTERFACE_DETAIL_DATA
        {
            public int CbSize;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]
            public string DevicePath;
        }

        [StructLayout(LayoutKind.Sequential)]
        internal struct SP_DEVICE_INTERFACE_DATA
        {
            public int CbSize;
            public Guid InterfaceClassGuid;
            public int Flags;
            public UIntPtr Reserved;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct BATTERY_QUERY_INFORMATION
        {
            public uint BatteryTag;
            public BATTERY_QUERY_INFORMATION_LEVEL InformationLevel;
            public int AtRate;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct BATTERY_STATUS
        {
            public POWER_STATE PowerState;
            public uint Capacity;
            public uint Voltage;
            public int Rate;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct BATTERY_WAIT_STATUS
        {
            public uint BatteryTag;
            public uint Timeout;
            public POWER_STATE PowerState;
            public uint LowCapacity;
            public uint HighCapacity;
        }
    }
}

win32-battery-example.cs

// Example from somewhere in MSDN
// 
//DWORD GetBatteryState()
// {
//#define GBS_HASBATTERY 0x1
//#define GBS_ONBATTERY  0x2
//  // Returned value includes GBS_HASBATTERY if the system has a 
//  // non-UPS battery, and GBS_ONBATTERY if the system is running on 
//  // a battery.
//  //
//  // dwResult & GBS_ONBATTERY means we have not yet found AC power.
//  // dwResult & GBS_HASBATTERY means we have found a non-UPS battery.

//  DWORD dwResult = GBS_ONBATTERY;

//  // IOCTL_BATTERY_QUERY_INFORMATION,
//  // enumerate the batteries and ask each one for information.

//  HDEVINFO hdev =
//            SetupDiGetClassDevs(&GUID_DEVCLASS_BATTERY, 
//                                0, 
//                                0, 
//                                DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
//  if (INVALID_HANDLE_VALUE != hdev)
//   {
//    // Limit search to 100 batteries max
//    for (int idev = 0; idev < 100; idev++)
//     {
//      SP_DEVICE_INTERFACE_DATA did = {0};
//      did.cbSize = sizeof(did);

//      if (SetupDiEnumDeviceInterfaces(hdev,
//                                      0,
//                                      &GUID_DEVCLASS_BATTERY,
//                                      idev,
//                                      &did))
//       {
//        DWORD cbRequired = 0;

//        SetupDiGetDeviceInterfaceDetail(hdev,
//                                        &did,
//                                        0,
//                                        0,
//                                        &cbRequired,
//                                        0);
//        if (ERROR_INSUFFICIENT_BUFFER == GetLastError())
//         {
//          PSP_DEVICE_INTERFACE_DETAIL_DATA pdidd =
//            (PSP_DEVICE_INTERFACE_DETAIL_DATA)LocalAlloc(LPTR,
//                                                         cbRequired);
//          if (pdidd)
//           {
//            pdidd->cbSize = sizeof(*pdidd);
//            if (SetupDiGetDeviceInterfaceDetail(hdev,
//                                                &did,
//                                                pdidd,
//                                                cbRequired,
//                                                &cbRequired,
//                                                0))
//             {
//              // Enumerated a battery.  Ask it for information.
//              HANDLE hBattery = 
//                      CreateFile(pdidd->DevicePath,
//                                 GENERIC_READ | GENERIC_WRITE,
//                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
//                                 NULL,
//                                 OPEN_EXISTING,
//                                 FILE_ATTRIBUTE_NORMAL,
//                                 NULL);
//              if (INVALID_HANDLE_VALUE != hBattery)
//               {
//                // Ask the battery for its tag.
//                BATTERY_QUERY_INFORMATION bqi = {0};

//                DWORD dwWait = 0;
//                DWORD dwOut;

//                if (DeviceIoControl(hBattery,
//                                    IOCTL_BATTERY_QUERY_TAG,
//                                    &dwWait,
//                                    sizeof(dwWait),
//                                    &bqi.BatteryTag,
//                                    sizeof(bqi.BatteryTag),
//                                    &dwOut,
//                                    NULL)
//                    && bqi.BatteryTag)
//                 {
//                  // With the tag, you can query the battery info.
//                  BATTERY_INFORMATION bi = {0};
//                  bqi.InformationLevel = BatteryInformation;

//                  if (DeviceIoControl(hBattery,
//                                      IOCTL_BATTERY_QUERY_INFORMATION,
//                                      &bqi,
//                                      sizeof(bqi),
//                                      &bi,
//                                      sizeof(bi),
//                                      &dwOut,
//                                      NULL))
//                   {
//                    // Only non-UPS system batteries count
//                    if (bi.Capabilities & BATTERY_SYSTEM_BATTERY)
//                     {
//                      if (!(bi.Capabilities & BATTERY_IS_SHORT_TERM))
//                       {
//                        dwResult |= GBS_HASBATTERY;
//                       }

//                      // Query the battery status.
//                      BATTERY_WAIT_STATUS bws = {0};
//                      bws.BatteryTag = bqi.BatteryTag;

//                      BATTERY_STATUS bs;
//                      if (DeviceIoControl(hBattery,
//                                          IOCTL_BATTERY_QUERY_STATUS,
//                                          &bws,
//                                          sizeof(bws),
//                                          &bs,
//                                          sizeof(bs),
//                                          &dwOut,
//                                          NULL))
//                       {
//                        if (bs.PowerState & BATTERY_POWER_ON_LINE)
//                         {
//                          dwResult &= ~GBS_ONBATTERY;
//                         }
//                       }
//                     }
//                   }
//                 }
//                CloseHandle(hBattery);
//               }
//             }
//            LocalFree(pdidd);
//           }
//         }
//       }
//        else  if (ERROR_NO_MORE_ITEMS == GetLastError())
//         {
//          break;  // Enumeration failed - perhaps we're out of items
//         }
//     }
//    SetupDiDestroyDeviceInfoList(hdev);
//   }

//  //  Final cleanup:  If we didn't find a battery, then presume that we
//  //  are on AC power.

//  if (!(dwResult & GBS_HASBATTERY))
//    dwResult &= ~GBS_ONBATTERY;

//  return dwResult;
// }

Hi, first of all thank you for the great code!
I just wanted to warn you that I got overflow errors with this: handle.ToInt32() == -1
I replaced it with handle.ToInt64() == -1 and seems to work fine.

Thank you for this sample code.
I've found out, that not erverytime the memberIndex of der battery is 0. (In my special case I had to use memberIndex 2), so
SetupDiEnumDeviceInterfaces(deviceHandle, Win32.GUID_DEVCLASS_BATTERY, 2, ref deviceInterfaceData); works, all other memberIndex fail on DeviceIoControl(...) later.
I've found an MSDN c++ example here, where they try numbers between 0 and 100 (why 100?).

Nearby,
in cases of failing memberIndices (like I wrote before) in
DeviceIoControl(...)
int errorCode = Marshal.GetLastWin32Error();
if ( errorCode != 0 )
{
throw Marshal.GetExceptionForHR( errorCode );
...

errorCode results to 2,
but then Marshal.GetExceptionForHR( 2 ) returns null.
so throw throws a NullReferenceExeption
Maybe not all Marshal.GetLastWin32Error() -Results map to a corresponding .NET exception.

@StevenJDH, would be nice if you post a link to your forked gist.

@daluu sure, here it is: https://gist.github.com/StevenJDH/c66655967e21072b1d8644456129efc0

OMG I SEARCHED SOO SO LONG FOR A LIVE CHARGE RATE SOLUTION AND HERE WE ARE THANK YOU SO SO MUCH IT JUST WORKS <3 <3 <3 <3

When I put this to arm64 device. I got errorCode 122 and 1784 (ERROR_INSUFFICIENT_BUFFER) and Object reference not set to an instance of an object from Line223 Win32.SetupDiGetDeviceInterfaceDetail(...

change line 221 -225 to follow works for me. I think this is also the proper way to get the reqSize of deviceInterfaceDetailData

Win32.SetupDiGetDeviceInterfaceDetail(
              deviceInfoSet, ref deviceInterfaceData, IntPtr.Zero, 0,
              out var reqSize, IntPtr.Zero);

            bool retval = Win32.SetupDiGetDeviceInterfaceDetail(
                deviceInfoSet, ref deviceInterfaceData, ref deviceInterfaceDetailData, reqSize,
                out _, IntPtr.Zero);