9 Kits comprised of an electronics circuit board assembly, electrical connectors, battery compartment and fasteners for mounting and electrically connecting batteries in parallel; kits comprised of an electronics circuit board assembly, electrical connectors, battery compartment and fasteners for mounting and electrically connecting lithium-ion batteries in parallel; parallel battery kit comprised of an electronics circuit board assembly, electrical connectors, battery compartment and fasteners for mounting and electrically connecting batteries in parallel; kits comprised of an electronics circuit board assembly, electrical connectors, battery compartment and fasteners for mounting and allowing one or more batteries to power an electronic/electrical device; kits comprised of an electronics circuit board assembly, electrical connectors, battery compartment and fasteners for mounting and allowing the use of one or more batteries for powering tankless dive systems