A system for retrofitting a wall of an aircraft monument includes a modular power charging unit and mounting hardware. The modular power charging unit includes a housing containing an electrical port component, a cable harness, and a switch. The housing has a plurality of screw holes and a back panel having an opening through which the cable harness extends. The mounting hardware includes a plurality of threaded inserts, each configured to be inserted into one of a plurality of mounting holes formed in the wall, and a plurality of screws, each configured to extend through a screw hole of the housing and into a threaded insert. The housing is configured to be secured to a first side of the wall so that the entirety of the housing projects outward from the first side and only the cable harness extends through a cable-harness hole formed through a thickness of the wall.