The design of portable power sources has generated much interest amongst power electronic design engineers. The Switch mode Power supply approach is preferred because it uses a small and light high frequency transformer. The use of new technology control circuitry also ensure improvement of power conversion efficiency. The aim of this project is to design a Portable Power source consisting of a battery charge and inverter circuit to supply domestic power i.e 240 V 50 Hz. using a rechargeable 12 V battery. The design will also take into account its weight, compactness, portability, reliability and safety requirements for everyday usage in the home as a substitute power source or out doors where electricity is required. Every chapter in this report outlines the design steps that has been made.