Python Dev Hides Ghost Window to Eavesdrop on Windows Battery Drama – No More Polling Heartache!

A Windows-only Python program has been developed to monitor battery percentage changes in real-time by subscribing to Windows power notifications. The script utilizes ctypes to call Win32 APIs directly and creates a hidden message-only window to receive system messages, printing updates whenever the battery percentage changes. The program runs continuously until the user exits with Ctrl+C, at which point it performs a clean shutdown. By using an event-driven approach, the script efficiently receives power management events from Windows, including battery percentage remaining and AC/DC power source changes. The program defines several Win32 constants and structures, such as WM_POWERBROADCAST and POWERBROADCAST_SETTING, to handle incoming messages and extract the new battery percentage. This design allows for immediate awareness of battery level changes without polling, making it suitable for background utilities, telemetry collectors, or any application requiring real-time power monitoring. The script demonstrates a practical pattern for integrating Python with low-level Windows notifications.