We propose a theoretical model of a fully functional nonreciprocal quantum battery inspired by the architecture of bacterial light-harvesting complexes. We assign functional roles to collective quantum optical subradiant and superradiant states and introduce a unimodal cavity to assist storage. The collective bright- and dark-state energies and total effective decay rates are obtained from an effective non-Hermitian Hamiltonian calculated using electromagnetic dyadic Green tensors. Upon varying the ring size, we find that work, flux, and power attain coincident maxima at the same intermediate ring size, whereas ergotropy reaches its maximum at a slightly larger ring size. The battery capacity is governed primarily by the ring size and depends weakly on the ring-central system coupling. Large coupling produces a pronounced finite-size optimum in ergotropy, whereas under weaker coupling the ergotropy increases monotonically with the battery capacity.