A shopping cart is equipped with an electrical/electronic component(s), such as a shopping assistant, that is electrically powered by a rechargeable power supply. A system is provided for continuously recharging the power supply as the shopping cart is propelled by the customer. In one embodiment, the wheels of the shopping cart are linked to a potential energy storage component, such as a coil spring. The spring is wound with each movement of the shopping cart, regardless of the distance that the cart travels. When the coil spring has been wound to a pre-determined torque, the spring is released to drive an input to an electrical generator. Once the potential energy in the spring has been dissipated the winding cycle begins again.