Patent ID: 8841040
Filing Date: 2014-09-23
Classification: H01M,Y02E

Abstract:
1. A method to cold-start a fuel cell system at subfreezing temperatures, the fuel cell system having a fuel cell stack upstream which is connected a heating device to heat a cooling agent to be circulated by a coolant pump, said method comprising: during a start-up time, at an ambient temperature that is below a temperature at which the fuel cell stack is capable of sustaining a normal operation, operating the fuel cell stack at an output power that is adequate to operate the heating device and the coolant pump; using the power provided by the fuel cell stack to operate the heating device for heating the cooling agent, as well as the coolant pump; circulating the cooling agent between the fuel cell stack and the heating device; and shutting off the heating device when the fuel cell stack has reached a preset temperature that is higher than the original temperature; wherein, the fuel cell system includes a starter battery; the starter battery is dimensioned such that it has an output capacity that is only able to supply electrical power to start the fuel cell system, until the fuel cell itself generates electrical power, wherein the output capacity of the starter battery is no greater than 1.5 kW, for less than five seconds; in a first stage the starter battery initially supplies power to the auxiliaries necessary for the supply of reactants to the fuel cell stack; and initial power supply is interrupted when the fuel cell stack generates electrical power.