Show warning when battery die

battery.c

// gcc battery.c -o battery.exe -Os -mwindows -Wl,--as-needed -s -nostdlib -luser32 -lkernel32 -march=native

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

static SYSTEM_POWER_STATUS status;

int _main() {
    SetProcessWorkingSetSize(GetCurrentProcess(), (SIZE_T)-1, (SIZE_T)-1);
    while (1) {
        GetSystemPowerStatus(&status);
        if (status.BatteryLifePercent < 50)
            MessageBox(NULL, "Battery below 50%", "Battery Warning", MB_SYSTEMMODAL | MB_ICONWARNING);
        Sleep(10 * 60 * 1000); // every 10m
    }
}