A direct isopropanol fuel cell adapted for use in ambient conditions and utilizing as fuel isopropanol and water preferably with isopropanol at relatively high concentrations representing 30% to 90% isopropanol.

A coolant control system of a fuel cell may include the fuel cell; a coolant line allowing a coolant to circulate therein and connected to the fuel cell to be heat-exchangeable with the fuel cell; an ion removal line provided with an ion filter and connected to a first portion and a second portion of the coolant line to allow a coolant branched from the first portion of the coolant line to pass through the ion filter and then flow into the second portion of the coolant line again; an adjusting valve adjusting a ratio between coolants respectively flowing into the coolant line and the ion removal line; and a controller engaged to the adjusting valve and configured for controlling the adjusting valve based on a temperature of the fuel cell or an output voltage of the fuel cell.

An electric power supply device supplies electric power to a work machine having an electric power source. The electric power supply device includes a fuel cell different from the electric power source and an electric power connecting section for transferring electric power between the electric power source and the electric power supply device. A control device for controlling the electric power supply device includes a rated capability obtaining section for obtaining the information indicating the rated value of the charge and discharge capability of the electric power source of the work machine in response to the electric power supply device being mounted in the work machine or the electric power supply device being able to utilize the electric power of the electric power source, and an operating condition determining section for determining the operating condition of the electric power supply device based on the rated value.

A main object of the present disclosure is to provide a fuel cell system capable of rapidly determining occurrence of a leak. The present disclosure achieves the object by providing a fuel cell system comprising: a fuel cell, a coolant circuit that circulates a cooling liquid to cool the fuel cell, a conductivity meter that measures a conductivity of the cooling liquid, and a determination device that determines a leak of the cooling liquid; wherein the determination device includes: an acquisition unit that acquires a conductivity of the cooling liquid from the conductivity meter, and a determination unit that determines a leak of the cooling liquid based on a fluctuation of the conductivity.

A fuel cell system that includes: an ion exchanger that is provided at a circulation path and that restores insulation resistance of a coolant; a detector that is provided at the circulation path at a downstream side of a radiator in a circulation direction of the coolant and that detects conductivity of the coolant; and a controller that is electrically connected to the detector and a pump and that controls driving of at least the pump. In a state in which the pump is stopped and in a case in which the insulation resistance of the coolant, which is obtained from the conductivity of the coolant that has been detected by the detector, becomes equal to or less than a specific value, the controller starts the driving of the pump such that the coolant passes through the ion exchanger.

A fuel cell system includes fuel cell, electrical storage device that stores electric power generated by the fuel cell, and control device of the fuel cell, the control device performs first control which causes the fuel cell to generate power and increases charging rate of the electrical storage device and second control which restricts output of the fuel cell to be smaller than that in the first control and decreases charging rate of the electrical storage device, and when switching condition, in which electric power demand from the external devices becomes greater than predetermined electric power or state in which electric power demand from the external devices is greater than the predetermined electric power continues for predetermined time, is satisfied, the control device increases power output by the fuel cell during the first control being performed to be larger than that before the switching condition was satisfied.

A fuel cell system includes: a fuel cell stack; a first cooling medium circuit through which a cooling medium for cooling the fuel cell stack flows; an ion exchanger that removes ions in the cooling medium; a second cooling medium circuit in which the average ion concentration of the cooling medium is lower than that of the cooling medium in the first cooling medium circuit; a switching valve that switches between a flow state and a low flow state; a pump configured to cause the cooling medium in the second cooling medium circuit to flow into the first cooling medium circuit; and a control unit that, when a stop period of the fuel cell system is longer than a reference period, drives the pump with the switching valve switched to the flow state after the instruction to start the fuel cell system is input.

A direct isopropanol fuel cell adapted for use in ambient conditions and utilizing as fuel isopropanol and water preferably with isopropanol at relatively high concentrations representing 30% to 90% isopropanol.

A temperature estimating apparatus is provided with: a deriving device configured to derive a slope function, on the basis of a value of a complex impedance of a battery at a predetermined frequency out of values obtained at a plurality of different temperatures and on the basis of a temperature of the battery when the complex impedance is obtained, wherein the slope function indicates a relation between the value of the complex impedance at the predetermined frequency and an inverse of the temperature of the battery; and an estimator configured (i) to measure a value of the complex impedance at the predetermined frequency and (ii) to substitute the measured value of the complex impedance at the predetermined frequency into the slope function, thereby estimating a temperature of the battery when the value of the complex impedance is measured.

A power supply device for the electrical power supply of at least one consumer has a primary power grid, in which a fuel cell device is present, having a secondary power grid, in which a battery is present, having an operating voltage range bounded at the top by a maximum voltage and at the bottom by a minimum voltage, and having an operating current strength range for powering the at least one consumer. An open circuit voltage of the fuel cell device corresponds at most to the maximum voltage of the battery, while there is present in the primary power grid an impedance spectroscopy device, which is designed to perform an impedance spectroscopy measurement on the fuel cell device or on individual fuel cells of the fuel cell device. A fuel cell vehicle has such a power supply device and a method for starting a power supply device.