This small utility that will automatically switch refresh rate of your screen you have chosen when you plug off your charger and sets it back when you plug it in.
Just install exe and run it whethever you want and it will install it in user folder and add itself to autorun. Also it will create config.json file which contains what resolution and min/max refresh rate your monitor has to perform.
Just go to path: %localappdata%\SRR and edit config.json(using notepad or whatever). Programm will auto accept changes.
SRR runs with a system tray icon. Right-click it and choose Exit. From the same menu you can pause/resume the service, reload config.json, open the config folder or logs, and toggle Run at startup to remove SRR from Windows autostart.
SRR polls power state once every 5 seconds and only reads config.json when its mtime changes (or on demand from the tray menu), so idle CPU usage is effectively 0%.