A mobile wireless communications device includes a power module with a first housing, at least one power cell carried by the first housing, and a first plurality of contact pads coupled to the at least one power cell and exposed on the first housing. A wireless module is adjacent the power module and includes a second housing having an opening therein, and wireless communications circuitry carried by the second housing and comprising a second plurality of contact pads aligned with the opening. A connector is in the opening and has a dielectric body, and a plurality of spring contacts carried by the dielectric body and exposed on opposite sides thereof coupling respective ones of the first and second pluralities of contact pads together.