Common power sources include:
- Batteries: Rechargeable or disposable cells (DC)
- Supercapacitors: (DC)
- Solar Panels (DC)
- Fuel Cells: Electrochemical devices (DC)
- External Power Supply: (DC or AC)
- Mains Power: Power from the local grid (AC, typically 110 V or 220 V).
- Energy Harvesting: RF, Piezoelectric, Thermal
- Capacitive/Inductive Power Transfer: Wireless power transfer