The first external electrode has a main body portion a part of which is buried in a side wall of a case and joining portions protruding from an end of the main body portion toward the inside of the case. One neck has double lead external threads and, below the threads, a conical wall having external ratchet teeth. In the second driving system, a second transmission transmits a second driving force generated by a second motor to the pressing roller. The structured format contains sections that describe details about the one or more portions of source code that have been identified as possibly having the program defects. Thanks to these, the battery can be charged or discharged at large current of 50 A or higher and can have a superior output characteristics and inputoutput characteristics. The present invention can reduce crystal defects of the nitride based 3-5 group compound semiconductor light emitting device and improve the crystallinity of a GaN GaN based single crystal layer in order to improve the performance of the light emitting device and ensure the reliability thereof.