Battery Information CSharp

[DllImport("kernel32.dll")]
static extern bool GetSystemPowerStatus(out SYSTEM_POWER_STATUS
   lpSystemPowerStatus)

using System;
using System.Runtime.InteropServices;

public class SystemPower
{
    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern Boolean GetSystemPowerStatus(out SystemPowerStatus sps);

    private enum ACLineStatus : byte
    {
        Offline = 0,
        Online = 1,
        Unknown = 255
    }

    private enum BatteryFlag : byte
    {
        High = 1,
        Low = 2,
        Critical = 4,
        Charging = 8,
        NoSystemBattery = 128,
        Unknown = 255
    }

    private struct SystemPowerStatus
    {
        public ACLineStatus LineStatus;
        public BatteryFlag flgBattery;
        public Byte BatteryLifePercent;
        public Byte Reserved1;
        public Int32 BatteryLifeTime;
        public Int32 BatteryFullLifeTime;
    }

    /// <summary>
    /// Returns true if a an AC Power Line is detected
    /// </summary>
    public static Boolean ACPowerPluggedIn()
    {
        SystemPowerStatus SPS = new SystemPowerStatus();
        GetSystemPowerStatus(out SPS);

        if (SPS.LineStatus == ACLineStatus.Online)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    /// <summary>
    /// Returns an integer representing the percent of battery charge remaining.
    /// </summary>
    public static Int32 BatteryCharge()
    {
        SystemPowerStatus SPS = new SystemPowerStatus();
        GetSystemPowerStatus(out SPS);

        return (Int32)SPS.BatteryLifePercent;
    }
}

private void btnCheckBattCharge_Click(object sender, EventArgs e)
{
    lblBatteryCharge.Text = SystemPower.BatteryCharge().ToString();
}