NOVELTY - Battery housing structure for a saddle-riding type electric vehicle having a battery placed between a front wheel and a rear wheel in a vehicle front-rear direction comprises: (a) a housing box (60); (b) an intake duct member having inlet ports (62a) formed in it for supplying air to the housing box; (c) an outlet port (62b) configured and arranged for discharging air rearwardly from the housing box; (d) a fan (64) for discharging air from the housing box; (e) a bypass passage (62c); (f) a first air flow control valve (63); and (g) a second air flow control valve (65).    USE - The battery housing structure is useful for a saddle-riding type electric vehicle (claimed).    ADVANTAGE - The housing box includes a main housing body and a lid body member, where the configuration enhances the maintainability and assemblability of the lid body member, because the lid body member includes the inlet ports, the outlet port, the bypass passage, the first air flow control valve, and the second air flow control valve, so that all the component parts concerning the control of the flow of the air are collectively provided to the lid body member. It is also constructed with a simpler structure.    DETAILED DESCRIPTION - Battery housing structure for a saddle-riding type electric vehicle having a battery placed between a front wheel and a rear wheel in a vehicle front-rear direction comprises: (a) a housing box (60) for receiving the battery comprising multiple battery cells; (b) an intake duct member having inlet ports (62a) formed in it for supplying air to the housing box, where the inlet ports are configured and arranged to receive air from an area forward of the housing box during operation of the vehicle; (c) an outlet port (62b) configured and arranged for discharging air rearwardly from the housing box; (d) a fan (64) for discharging air from the housing box; (e) a bypass passage (62c) operatively connecting a portion of the housing box downstream of the fan with a portion of the housing box proximate the inlet ports; (f) a first air flow control valve (63) for selectively controlling flow of air from the inlet ports to the housing box, or from an exit of the bypass passage to the housing box; and (g) a second air flow control valve (65) for selectively controlling flow of air from the housing box to the outlet port, or from the housing box to an entrance of the bypass passage. INDEPENDENT CLAIMS are included for:    (1) a temperature control system comprising the battery housing structure and a controller for controlling operations of the first air flow control valve and the second air flow control valve based on an output received from a temperature sensor arranged in at least one of the inlet ports, the outlet port, and the housing box;    (2) a temperature control system comprising the battery housing structure and a controller for controlling an air flow rate of the fan in order to regulate a temperature of the battery cells, where the controller is operatively connected to a temperature sensor arranged in at least one of the inlet ports, the outlet port, and the housing box;    (3) an electric vehicle comprising: (a) a battery placed between a front wheel and a rear wheel in the vehicle, where the battery comprises cells; (b) a housing box for receiving the battery; (c) a lid body having inlet ports and an outlet port formed in it, the inlet ports are configured and arranged to receive air from an area forward of the housing box during operation of the vehicle, the outlet port is configured to discharge air rearwardly from the housing box; (d) a fan for discharging air from the housing box through the outlet port, the lid body having a bypass passage formed in it, the bypass passage operatively connecting a downstream side of the fan with the inlet ports; (e) a first air flow control valve for selectively controlling flow of air from the inlet ports to the housing box, or from an exit of the bypass passage to the housing box; and (f) a second air flow control valve for selectively controlling flow of air from the housing box to the outlet port, or from the housing box to an entrance of the bypass passage; and    (4) a method of regulating a temperature of a battery in an electric vehicle, where the battery is disposed in a battery compartment of a battery housing structure arranged between front and rear wheels of the vehicle; the battery housing structure comprising a fan; and a lid body having inlet ports, an outlet port, and a bypass passage connecting downstream side of the fan with the inlet ports formed in it; a first air flow control valve for selectively controlling flow of air from the inlet ports to the housing box, or from an exit of the bypass passage to the housing box; a second air flow control valve for selectively controlling flow of air from the housing box to the outlet port, or from the housing box to an entrance of the bypass passage; a controller for controlling operations of the first and second air flow control valves; and a temperature sensor for sensing temperature of the battery, comprising: (a) sensing a present temperature of the battery using a temperature sensor; (b) controlling the first air flow control valve and the second air flow control valve so that air flows from the inlets to outlet port via the battery compartment when the temperature measured by the temperature sensor is higher than a reference value; and (c) controlling at least one of the first air flow control valve and the second air flow control valve so that the inlet ports and the outlet port are closed and air re-circulates within the battery housing structure when the temperature measured by the temperature sensor is lower than the reference value.    DESCRIPTION OF DRAWING(S) - The drawing shows a side cross-sectional view of the housing box.    Inlet ports (62a)    Outlet port (62b)    Bypass passage (62c)    First air flow control valve (63)    Fan (64)    Second air flow control valve (65)