Cannot rise events when SystemInformation.PowerStatus.BatteryLifePercent matches a specific value

Question

I wanted my program to show a simple dialog form when the battery percentage of my laptop reaches 80%. I've used SystemInformation.PowerStatus.BatteryLifePercent to achieve the same and have used a timer event to monitor the battery percentage changing while charging or discharging and check for the battery to reach 80% charge using the above mentioned method. Below is my code.

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Timer1.Enabled = True
    TimerChargeMonitor.Interval = 100
    TimerChargeMonitor.Enabled = True
End Sub

Private Sub TimerChargeMonitor_Tick(sender As Object, e As EventArgs) Handles TimerChargeMonitor.Tick
    If SystemInformation.PowerStatus.BatteryLifePercent = 0.8 Then
        NotifBox.Show()
        TimerChargeMonitor.Enabled = False
    End If
End Sub

The problem is it doesnt work. The dialog form doesnt show up when the battery percentage reaches 80% or any other number.

Answer 1

Your code needs some adjustments:
SystemInformation.PowerStatus.BatteryLifePercent returns a single.
It's better to test it with >= because its value might be slightly different from what you are expecting here.

Then, you have to stop your timer before showing a MessageBox (if that is what NotifBox.Show() is).

So your code would be:

If SystemInformation.PowerStatus.BatteryLifePercent >= 0.8 Then
    TimerChargeMonitor.Stop()
    NotifBox.Show()
End If

As a note, the tick interval seems way too low for this application.
Maybe set it to TimerChargeMonitor.Interval = 5000
(I don't know what the other timer is for, here).