using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

using Microsoft.Win32;

namespace VistaLaptopBatterySaver
{
public partial class Form1 : Form
{
/*
* Copyright Clint Rutkas May 2007
*
*/
[DllImport(“dwmapi.dll”, PreserveSig = false)]
public static extern void DwmEnableComposition(bool bEnable);

[DllImport(“dwmapi.dll”, PreserveSig = false)]
public static extern bool DwmIsCompositionEnabled();

public Form1()
{
InitializeComponent();
enableToolStripMenuItem.Checked = DwmIsCompositionEnabled();
}

private void Form1_Load(object sender, EventArgs e)
{
SystemEvents.PowerModeChanged += new PowerModeChangedEventHandler(SystemEvents_PowerModeChanged);
UpdatePowerInfo();
}

private void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
UpdatePowerInfo();
}

private void UpdatePowerInfo()
{
if (enableToolStripMenuItem.Checked)
{
PowerStatus ps = SystemInformation.PowerStatus;

DwmEnableComposition((ps.PowerLineStatus == PowerLineStatus.Online));
}
}

private void enableToolStripMenuItem_CheckStateChanged(object sender, EventArgs e)
{
UpdatePowerInfo();
}

private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
Close();
}

private static void aboutToolStripMenuItem_Click(object sender, EventArgs e)
{
AboutBox ab = new AboutBox();
ab.Show();
}
}
}

No explanation as to what it does or how it is supposed to affect battery life.

It disables Aero when on battery power. Then re-enables it when plugged back in.