The following VB.NET will make use of the SystemInformation class in order to obtain the battery charge status in percentages and the current power source: AC power / battery charging or battery power / battery not charging.

'Objects for retrieving the information

Dim psBattery As PowerStatus = SystemInformation.PowerStatus

Dim perFull As Single = psBattery.BatteryLifePercent

'Show the remaining battery power in percentages

MsgBox("Total battery power remaining: " & perFull * 100 & "%")

'Is the battery charging?

If psBattery.PowerLineStatus = PowerLineStatus.Online Then

    MsgBox("Battery charge status: Charging")

ElseIf psBattery.PowerLineStatus = PowerLineStatus.Offline Then

    MsgBox("Battery charge status: Not charging")

End If