At our homes, all appliances are connected to the Mains supply, which gives a voltage of about 230V. But many appliances need only small amount of voltage to work (e.g 25V), so
Orbea Bike Drivetrains: Bicycle Drivetrain Parts & Sets for Sale | Jenson USA
AC DC Adapter for Samsung LS22C350HS/ZA S22C350HS LS22C570HS/ZA S22C570HS LCD 731698129727 | eBay
Blue Smart IP67 Charger 12/7(1) 230V AU/NZ | Wabi Solar