VB.NET : Battery percentage code isn't updated in real-time

Question

I made a program with Visual Studio to display battery percentage using a Label and ProgressBar, the problem I had is that the battery percentage isn't updated in real time although I already put TimerBattery.Tick() in Form_Load, I have to relaunch my app to update the information. Any idea what's wrong with my code?

Dim psBattery As PowerStatus = SystemInformation.PowerStatus
Dim perFull As Single = psBattery.BatteryLifePercent

 Private Sub TimerBattery_Tick(sender As Object, e As EventArgs) Handles TimerBattery.Tick
        If perFull * 100 >= 100 Then
            ProgressBar1.Value = 100
        ElseIf perFull * 100 < 100 Then
            ProgressBar1.Value = perFull * 100
        End If
        If psBattery.PowerLineStatus = PowerLineStatus.Online Then
            LabelBatt.Text = "Battery " & perFull * 100 & "%"
            LabelBatt2.Text = perFull * 100 & "%, charging"
        ElseIf psBattery.PowerLineStatus = PowerLineStatus.Offline Then
            LabelBatt.Text = "Battery " & perFull * 100 & "%"
            LabelBatt2.Text = perFull * 100 & "%, not charging"
        End If
End Sub

Answer 1

You need to move at least the line that initializes the perFull variable inside the Tick event. Otherwise the perFull value is calculated just one time when you open the form class.

Dim psBattery As PowerStatus = SystemInformation.PowerStatus

Private Sub TimerBattery_Tick(sender As Object, e As EventArgs) Handles TimerBattery.Tick

    ' Now at each Tick event you read the PowerStatus value and
    ' execute the Tick logic with the correct value        
    Dim perFull As Single = psBattery.BatteryLifePercent

    If perFull * 100 >= 100 Then
        ProgressBar1.Value = 100
    ElseIf perFull * 100 < 100 Then
        ProgressBar1.Value = perFull * 100
    End If
    If psBattery.PowerLineStatus = PowerLineStatus.Online Then
        LabelBatt.Text = "Battery " & perFull * 100 & "%"
        LabelBatt2.Text = perFull * 100 & "%, charging"
    ElseIf psBattery.PowerLineStatus = PowerLineStatus.Offline Then
        LabelBatt.Text = "Battery " & perFull * 100 & "%"
        LabelBatt2.Text = perFull * 100 & "%, not charging"
    End If

End Sub