PURPOSE: To enable a user to easily judge whether the battery is being charged or not with a plug socket part by lighting up the indication means of the plug socket part provided with a push button switch and an indication means, and putting it out when the charge stops.

CONSTITUTION: When the attachment plugs of power supply lines to a battery as a power source for driving an electric carrier car in request of charging are plugged into the plugs H1 and H2 of the plug socket 2 connected to a charger board, this connector enables the automatic start of the charging of a battery, and also lights up an indication means (for example, a light emitting diode, etc.) 4, and puts out the indication means 4 when the voltage of the battery reaches reference voltage and the charging is finished. On the other hand, it is controlled to stop the charging by operating a push button switch 5, and further start the charge by operating the push button switch 5. Hereby, it can be easily judged whether the battery 2 is in charging or not with the plug socket part 2.