A battery charging system comprising: a current source; a battery; and a voltage and current regulator, which regulates voltage applied to the battery and current supplied to the battery. The interconnect structure includes a channel configured to receive a portion of a cross member. The second injecting port is placed in parallel in a radius direction with respect to the first injecting port and is placed so that an orbiting scroll wrap does not practically communicate with the orbiting outer compression chamber in the state in which the orbiting scroll wrap is in contact with the outer side of a fixed scroll wrap.