Recently, as electrical components of a vehicle have been abruptly increased in kind and number, energy consumption of a battery for vehicle installation becomes growing, and thus charge to such a battery comes to be frequently carried out. There are a contact type and a plug type as a method for charging a battery for vehicle installation in the related art.
<Related Art 1: Contact Type in a Battery Mount State>
As a battery charging method in the related art in an electric vehicle (EV vehicle) such as a carrier that is used for the work in the yard, charging is performed by simply making front ends of a vehicle side terminal and a charger side terminal come into contact with each other (see Patent Document 1).
In this case, in order to secure connection reliability, one terminal pushes the other terminal by the repulsion of a spring to make the terminals come into certain contact with each other. According to this battery charging method 1 in the related art, the battery has already been installed in the vehicle, and thus it is not necessary to make the battery disengaged from an in-vehicle electric device side connector. Therefore, as advantages, terminals rarely rub each other, and thus the lifespan of the battery terminal is not shortened. By contrast, as problems, the electric vehicle is stopping during charging and thus is not usable.
<Related Art 2: Plug Type in a Battery Exchange Method>
In order to solve a problem called shortening of the charge time (=stoppage time), there is a battery exchange method to take out a battery which has been discharged from an undercarriage of a vehicle and to replace the discharged battery by a battery which has been charged.
FIGS. 9A and 9B are views explaining a battery exchange method in the related art. FIG. 9A is a conceptual view of the battery exchange method, and FIG. 9B is a cross-sectional view illustrating terminal shapes of connectors of respective devices. According to the battery exchange method as illustrated in FIG. 9A, when a battery B1 for vehicle installation that is installed in a vehicle A comes to have been discharged, the battery B1 for vehicle installation that has been discharged is taken out from the vehicle A, and another battery B2 for vehicle installation which has already been charged is loaded on the vehicle A. Accordingly, since the charge time can be reduced, the stoppage time is with time only for connector connection, and thus the stoppage time can be greatly reduced.
According to the work of the meantime, a battery side connector terminal 20T which is the male terminal of a connector 20 of the battery B1 that has been discharged is taken off from the female terminal 100T of a vehicle side connector 100 that feeds in-vehicle electric devices 50 that are various motors such as power windows in the vehicle through a wire (electric wire), and then is put into a hollow part 100V of the female terminal 100T of a charger side connector 100 (that is, a connector for feeding from a charger 60 which supplies DC current that is obtained by rectifying an AC power AC to the wire W) outside the vehicle. On the other hand, another battery B2 for vehicle installation that has been charged is carried to the inside of the vehicle, and the battery side connector terminal 20T of the connector 20 of the battery B2 for vehicle installation is put into the hollow part 100V of the female terminal 100T of the vehicle side connector 100 that feeds the in-vehicle electric devices 50.
In this case, a connector housing 10 and the female terminal 100T of the vehicle side connector 100 have the same shapes as a connector housing 10 and the female terminal 100T of the charger side connector 100, respectively, and the battery side connector terminal 20T of the battery B1 or B2 for vehicle installation is taken off from the hollow part 100V of the female terminal 100T of one side connector 100, and then is put into the hollow part 100V of the female terminal 100T of the other side connector 100.
In the case of adopting such a battery exchange method, since the vehicle side connector is affected by vibration and dust during traveling of the vehicle, contacts may come off or dust may get in the contact type connector, and thus satisfactory reliability may not be achieved. Therefore, plug-type connector is generally used to achieve the secure connection between the connector terminals.