  Quantum devices are systems that can explore quantum phenomena, like
entanglement or coherence, for example, to provide some enhancement performance
concerning their classical counterparts. In particular, quantum batteries are
devices that use entanglement as main element in its high performance in the
charging powerful. In this paper, we explore the quantum battery performance
and its relationship with the amount of entanglement that arises during the
charging process. By using a general approach to a two and three-cell battery,
our results suggest that entanglement is not the main resource to quantum
batteries, where there is a non-trivial correlation-coherence trade-off as
resource for the high efficiency of such quantum devices.
