Patent ID: 8142945

Claim:
A fuel cell system comprising: a plurality of peripheral devices comprising: an oxidant supplier for supplying an oxidizing agent to a fuel cell for generating electricity through an electrochemical reaction between a mixed fuel and the oxidizing agent, a fuel supplier for supplying a high concentration fuel to a mixing tank for storing water and un-reacted fuel recovered from a fluid exhausted from the fuel cell, a water supplier for supplying water to the mixing tank, and a fuel feeder for feeding the mixed fuel stored in the mixing tank to the fuel cell; an electricity storage device electrically connected with the peripheral devices; and a controller configured to obtain a signal to sense a concentration of the mixed fuel and to obtain a signal to sense a level of the mixed fuel through a level sensor coupled to the mixing tank in response to an inputted starting request signal and programmed to sequentially operate the peripheral devices by using electric energy stored in the electricity storage device according to an operation priority, wherein the controller is programmed to sequentially operate the oxidant supplier, the fuel feeder, and the fuel supplier in order when the concentration is within a reference concentration range, wherein the controller is programmed to sequentially operate the fuel supplier, the oxidant supplier, and the fuel feeder in order when the concentration is below the reference concentration range, and wherein the controller is programmed to sequentially operate the water supplier first when the sensed level of the mixed fuel is below a reference level.