The first thing that strikes me about this dump file is that you’re using BatteryBar. Looking at the stack traces in that dump, I see that there’s some C# code waiting on a message box.
Given that BatteryBar…
- is written in C#
- is actual software that might care about the battery
- is implicated¹ in the stack that is waiting on the message box
… I’m going to guess that this battery dialog is coming from BatteryBar.
In retrospect, I see you did indicate that BatteryBar might be the cause!
Child-SP RetAddr Caller, Callee
000000000300a630 00007ff8c88897ee user32!MessageBoxW+0x4e, calling user32!MessageBoxTimeoutW
000000000300a840 00007ff84bdbb1fc 00007ff84bdbb1fc, calling System_Windows_Forms_ni+0xb43460
0:001> !U /d 00007ff84bdbb1fc
Normal JIT generated code
BatteryBar.Utilities.Controls.MessageBox.Show(System.Windows.Forms.IWin32Window, System.String, System.String, BatteryBar.Utilities.Controls.MessageBoxType)