Abstract: A fuel cell system is arranged to charge a secondary battery, which is detachable from the fuel cell system, and to supply electric power to a load. The fuel cell system includes a cell stack having a plurality of fuel cells and a controller having a CPU. During power generation in the cell stack, the CPU determines whether or not the secondary battery has been removed from the fuel cell system based on a voltage drop in the cell stack. With the determination that the secondary battery has been removed, the CPU turns off a relay and power supply from the cell stack to the load is stopped. The fuel cell system reliably maintains its operation even after removal of the secondary battery.

Abstract: A fuel cell system includes a cell stack, a temperature sensor which detects a temperature of the cell stack, an outside air temperature sensor which detects an outside air temperature, and a CPU which controls a process in the fuel cell system. When the temperature of the cell stack is lower than a predetermined temperature, the fuel cell system performs a temperature raising operation of the cell stack by making the concentration of aqueous methanol solution in an aqueous solution tank higher than in a normal operation and by making an output of an aqueous solution pump greater than in the normal operation. The CPU sets a run time for the temperature raising operation based on a detection result from the outside air temperature sensor, a detection result from the temperature sensor, and a run time setting table which is stored in a memory. The fuel cell system is capable of raising a temperature of the fuel cell quickly and stably to the predetermined temperature.

Abstract: A motorbike is mounted with a fuel cell system which includes a cell stack, a secondary battery which is charged by the cell stack and a controller which has a CPU. After receiving an operation stop command which is issued from a main switch, the CPU estimates a charging time for a charge rate of the secondary battery to attain a target value, based on a voltage of the secondary battery and a charge current which are detected based on detection signals from a voltage detection circuit and an electric current detection circuit, as well as based on a charging time estimation table stored in a memory. The charging time estimated by the CPU is displayed in a display.

Abstract: A fuel cell system preferably includes a fuel cell which generates electric energy by electrochemical reaction, an aqueous solution tank which holds the methanol aqueous solution, a water tank which holds fluid discharged from the fuel cell, a fluid level sensor for detecting an amount of fluid in the water tank, a water pump which recycles fluid in the water tank to the aqueous solution tank, and a CPU which controls components of the fuel cell system. After power generation is finished, the water pump is driven to recycle all the fluid in the water tank to the aqueous solution tank. Further, after power generation is finished or before power generation is started, the fluid level sensor detects the amount of fluid in the water tank. If the amount of fluid is not smaller than a predetermined amount, the water pump is driven to recycle fluid in the water tank to the aqueous solution tank. The fuel cell system has a simple construction and is capable of preventing fluid from being discharged outside.

Abstract: A fuel cell system includes a fuel tank which stores a methanol fuel, an aqueous solution tank which stores a methanol aqueous solution having a concentration less than that of the methanol fuel, a fuel pump which supplies the methanol fuel stored in the fuel tank to the aqueous solution tank, a fuel cell stack which is supplied with the methanol aqueous solution from the aqueous solution tank for generating electric energy through electrochemical reactions, a water tank which stores water to be supplied to the aqueous solution tank, a water pump for supplying water stored in the water tank to the aqueous solution tank, a concentration sensor which detects the concentration of the methanol aqueous solution supplied to the fuel cell stack, a fluid surface detection sensor which detects a fluid surface height of the methanol aqueous solution in the aqueous solution tank, and a controller which controls a supply operation of the fuel pump and the water pump based on an output from the concentration sensor, and s

Abstract: A fuel cell system is capable of easily detecting an abnormality in an aqueous solution container, a circulation unit or a liquid level adjusting unit. The fuel cell system includes an aqueous solution tank which holds aqueous methanol solution; a level sensor which outputs one of detection signals HIGH and LOW in accordance with the liquid level in the aqueous solution tank; an aqueous solution pump for circularly supplying aqueous methanol solution to a cell stack; a water pump for supplying water to the aqueous solution tank; and a CPU which controls operation of the fuel cell system. The CPU detects that an abnormality exists based on comparison between a first predetermined time and a required time (LOW time) which is a time required for a detection signal to be changed from LOW to HIGH, or on comparison between a second predetermined time and a required time (HIGH time) which is a time required for the detection signal to be changed from HIGH to LOW.

Abstract: A fuel cell system is capable of determining abnormalities in an aqueous solution supply without providing new sensors for abnormality detection. A fuel cell system includes a cell stack, and an aqueous solution supply arranged to supply the cell stack with aqueous methanol solution. The aqueous solution supply is capable of making circulatory supply of aqueous methanol solution to the cell stack, and includes a main flow channel connected with a cell stack; a sub flow channel branched off the main flow channel and connected with a gas source; an aqueous solution tank which holds aqueous methanol solution; and an aqueous solution pump. An ultrasonic sensor is provided in the sub flow channel. The ultrasonic sensor is located at a place higher than a liquid level in the aqueous solution tank when the aqueous solution pump is stopped. Abnormalities in the aqueous solution supply are determined based on a result of concentration information detection from the ultrasonic sensor.

Abstract: A fuel cell system is capable of shifting to a normal operation quickly, and can be provided in transportation equipment such as a motorbike. The fuel cell system includes a cell stack which has a plurality of fuel cells; an aqueous solution tank which holds aqueous methanol solution to be supplied to the cell stack; a water pump which supplies water to the aqueous solution tank; an electric current detection circuit which detects an electric current value of the cell stack; and CPU which controls the fuel cell system. The CPU drives the water pump, and thereby starts a liquid amount adjustment if the electric current value detected by the electric current detection circuit becomes not lower than a predetermined value after power generation of the cell stack is started.

Abstract: A fuel cell system and a control method enables a smooth shift from a heat-up operation to a normal operation in a simple operating process. The fuel cell system includes a cell stack, an aqueous solution holding device having aqueous solution tanks which store aqueous methanol solution, and a first connecting portion and a second connecting portion which connect the aqueous solution tanks with each other, and a temperature sensor which detects a temperature of the aqueous methanol solution. Based on a result of a temperature detection, a setting is made for one of a first mode where the aqueous methanol solution in the aqueous solution tank is circulated to the cell stack and a second mode where the aqueous methanol solution in the aqueous solution tanks is circulated to the cell stack.

Abstract: A fuel cell system and operation methods therefore are capable of ensuring transfer to normal operation while maintaining convenience. A fuel cell system includes a cell stack, a secondary battery, and a controller including a CPU, a main switch, and a stop button. After the main switch is turned OFF, if there is no power generation stopping command from the stop button, the CPU stops power generation in the cell stack after continuing power generation in the cell stack until a charge rate of the secondary battery becomes not lower than a first threshold value. If the charge rate is not lower than a second threshold value and is lower than the first threshold value, generation in the cell stack is stopped in response to the power generation stopping command from the stop button.

Abstract: A fuel cell system including a fuel cell stack is capable of raising the temperature of a fuel cell stack to a predetermined temperature within a short time without decreasing methanol fuel utilization efficiency. During system startup, the concentration of methanol aqueous solution which is to be supplied to the fuel cell stack is detected by a concentration sensor, and the temperature of the fuel cell stack is detected by a temperature sensor. A target concentration of methanol aqueous solution is determined by making reference to data stored in a memory, which indicates correspondence between the temperature of the fuel cell stack and the target concentration of methanol aqueous solution, and based on the temperature of the fuel cell stack detected by the temperature sensor. The amount of input of methanol fuel is determined based on the concentration of the methanol aqueous solution and the target concentration, and the determined amount of the methanol fuel is inputted to the methanol aqueous solution.

Abstract: A fuel cell system and an operation method thereof are capable of re-starting the system reliably even after the system has been tilted to or beyond a predetermined limit. The fuel cell system includes a fuel cell having an anode and a cathode. A tilt sensor detects a tilt of the fuel cell system not smaller than a predetermined limit, and a memory stores a record that the fuel cell system was tilted to or beyond the predetermined limit. When the fuel cell is started thereafter, the fuel cell is started in a recovery mode if there is a record of a tilt not smaller than the predetermined limit in the memory. The fuel cell is not started, however, if a tilt time since the detection of the tilt of the fuel cell system not smaller than the predetermined limit is not smaller than a first predetermined value.

Abstract: A fuel cell system and an operating method thereof are capable of reliably reducing fuel crossover and electrolyte film deterioration. The fuel cell system includes a fuel cell having an electrolyte film, an aqueous solution circulation unit arranged to circulate a supply of aqueous methanol solution to the fuel cell, a fuel supply arranged to supply the aqueous solution circulation unit with methanol fuel that has a concentration not lower than that of the aqueous methanol solution, and a main switch. After the main switch is turned OFF, a CPU controls fuel supply operation of the fuel supply so that the amount of fuel supply to the aqueous solution circulation unit is decreased. Thereafter, power generation operation of the fuel cell is controlled so that the power generation is stopped, with the concentration of aqueous methanol solution lower than before the main switch was turned OFF.

Abstract: An electric motor-driven vehicle comprises a seat disposed centrally on a vehicle body, a loading platform located over a loading platform receiving frame and behind the seat, and a plurality of main frame rails connected to the loading platform receiving frame. The vehicle further comprises a fuel supply piping system, at least one battery, a fuel cell and at least one fuel tank, all disposed so as to efficiently use the space within the vehicle body, and all protected from external forces by the loading platform receiving frame. A plurality of partition walls separate the at least one battery and the fuel cell from the at least one fuel tank and provide additional protection against external forces to the fuel cell and the at least one fuel tank.

Abstract: A fuel cell system includes a fuel cell which generates electric energy by electrochemical reactions, an ultrasonic sensor which detects physical information of an aqueous methanol solution to be used for the generation of electric energy by the fuel cell based on an ultrasonic propagation speed in the aqueous methanol solution, a voltage sensor which detects electrochemical information of the aqueous methanol solution based on an open-circuit voltage of the fuel cell, and first and second temperature sensors which detect temperatures of the aqueous methanol solution. The system further includes a CPU which obtains a concentration of the aqueous methanol solution based on the physical information and a concentration of the aqueous methanol solution based on the electrochemical information, and selects one of the concentrations based on the detected temperature. The fuel cell system is capable of detecting a concentration of the aqueous fuel solution easily and accurately.

Abstract: A direct methanol fuel cell system is constructed to sit stably and to minimize external influences of impacts on a fuel cell stack. The fuel cell system includes an aqueous solution tank for storing a methanol aqueous solution, a fuel tank for storing a methanol fuel to be supplied to the aqueous solution tank, and a fuel cell stack supplied with the methanol aqueous solution from the aqueous solution tank for generating electric energy through electrochemical reactions. The fuel tank and the aqueous solution tank are disposed above the fuel cell stack.

Abstract: A fuel cell system that is capable of handling gasified fuel in an aqueous solution tank includes an aqueous solution tank which holds fuel aqueous solution, a fuel cell including an anode supplied with the fuel aqueous solution from the aqueous solution tank, and a cathode provided with a catalyst containing platinum Pt, an air supplying unit including an air pump and arranged to supply air to the cathode in the fuel cell, and a gas guide arranged to add a gas containing gasified methanol from the aqueous solution tank to the air to be sent to the cathode.

Abstract: An electric motor-driven vehicle comprises a seat disposed centrally on a vehicle body, a loading platform located over a loading platform receiving frame and behind the seat, and a plurality of main frame rails connected to the loading platform receiving frame. The vehicle further comprises a fuel supply piping system, at least one battery, a fuel cell and at least one fuel tank, all disposed so as to efficiently use the space within the vehicle body, and all protected from external forces by the loading platform receiving frame. A plurality of partition walls separate the at least one battery and the fuel cell from the at least one fuel tank and provide additional protection against external forces to the fuel cell and the at least one fuel tank.

Abstract: A number of embodiments of wheel locks for vehicle wheels having an opening are disclosed. In each embodiment, the lock includes a plurality of pivotally connected elongated members having end members that are provided with a locking means for locking them together. As a result, the lock can be inserted through the wheel and around a fixed object and locked like a chain. Various embodiments are disclosed for protecting the pivot pins of the pivotal connections from attack and for restraining the pivotal movement of the elongated members. In some embodiments, the pivotal movement is restrained by placing a frictional drag on the components so that the elements cannot freely pivot. In other embodiments the degree of pivotal movement in one direction is limited more than in another direction so that the lock can only be installed in the correct relationship.

Abstract: A filter device for cleaning water and having a reinforcing member for preventing reduction of filtering area due to deformation of filter membrane. The filter device comprises a generally cylindrical casing and a filter element contained in said casing for passing water from the primary side thereof to the secondary side thereof, the filter element including a corrugated filter membrane and a reinforcing member for supporting the corrugated filter membrane. The filter device is particularly suited for use together with a powdered absorbent such as activated carbon.