  Energy can be stored in quantum batteries by electromagnetic fields as
chargers. In this paper, the performance of a quantum battery with single and
double chargers is studied. It is shown that by using two independent charging
fields, prepared in coherent states, charging power of the quantum battery can
be significantly improved, though the average number of embedded photons are
kept the same in both scenarios. Then the results reveal that for the case of
initially correlated states of the chargers the amount of extractable energy,
measured by ergotropy, is more than initially uncorrelated ones, with
appropriate degrees of field's intensities. Though the correlated chargers lead
to greater reduction in purity of quantum battery, more energy and in turn,
more ergotropy is stored in this case. In addition, we study the
battery-charger mutual information and Von Neumann entropy and by using their
relation, we find that both quantum and classical correlations are generated
between the quantum battery and chargers. Then we study quantum consonance of
the battery as the non-local coherence among it's cells and find some
qualitative relations between the generation of such correlations and the
capability of energy storage in the quantum battery.
