TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The lead member (6) has a safety device (11) on its portion(s). The safety device is a positive temperature coefficient (PTC) device. The secondary battery module includes corresponding insulating mediators (7) having a hole (7a) for guiding the bent portion of each lead member, two auxiliary terminals (8) disposed respectively on one electrode terminal of a top cell and on one electrode terminal of a bottom cell for connection to corresponding electrode terminals of the two outmost cells, two insulating supports (9) for covering corresponding electrode terminals of the two outmost cells and having a shape that partially exposes corresponding auxiliary terminals, and at least two fasteners (10) for insulatively fastening insulating supports, lead members, insulating mediators, electrode terminals, and auxiliary terminals. Each lead member has safety device peripheries bent at a predetermined angle with respect to the axial line of lead member, and the hole formed on the corresponding insulating mediator has a sloping surface forming a predetermined angle with respect to the axial line of insulating mediator. Each insulating mediator has cylindrical bosses at positions where the fasteners penetrate to prevent short circuit caused by the lead members and fasteners, cut portions and alignment projections at one end, and interfitting recesses and interfitting projections at the other end respectively on the bottom and top portions to stack up and fix the cells (5) to a predetermined height. At least one of the cylindrical bosses has ribs formed in an outward radial direction so that heat transferred through the electrode terminals (5a) of the cells can be smoothly released out. Each insulating support has cylindrical bosses at positions where the fasteners penetrate to prevent accidental short circuit caused by the electrode terminals, auxiliary terminals, and fasteners. Each insulating support has an opening cut in a longitudinal direction on its end(s). The fasteners comprise pairs of bolts (10a) and nuts (10b). Each cell includes a cell protection circuit for electrical protection from overcurrent, overcharge, or overdischarge conditions.    TECHNOLOGY FOCUS - METALLURGY - Preferred Materials: The lead member is made of copper, aluminum, nickel-copper, and/or copper-aluminum.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The insulating mediators and supports are made of polybutylene terephthalate, acrylonitrile-butadiene-styrene, and/or polycarbonate resin.