  Quantum nano-devices are fundamental systems in quantum thermodynamics that
have been the subject of profound interest in recent years. Among these,
quantum batteries play a very important role. In this paper we lay down a
theory of random quantum batteries and provide a systematic way of computing
the average work and work fluctuations in such devices by investigating their
typical behavior. We show that the performance of random quantum batteries
exhibits typicality and depends only on the spectral properties of the time
evolving operator, the initial state and the measuring Hamiltonian. At given
revival times a random quantum battery features a quantum advantage over
classical random batteries. Our method is particularly apt to be used both for
exactly solvable models like the Jaynes-Cummings model or in perturbation
theory, e.g., systems subject to harmonic perturbations. We also study the
setting of quantum adiabatic random batteries.
