Certain exemplary embodiments comprise a method, which can comprise automatically causing a representation of body tissue to be rendered. A battery pack 10 has a battery module unit 50 that is formed from a plurality of arranged battery modules 40, each of which has a plurality of cells 30 in a case 41, a cooling air flow passage 20 where a cooling air flow 21 flows, and a gas exhaust duct 60 which forms a gas exhaust passage. A resonator is formed by the combination of the transformer and capacitive elements of the transmitter and receiver. A flexible snap member is mounted in one of the recesses such that it can flex at least partially into the other of the recesses when the recesses are aligned.