  Recently, it has been shown that energy can be deposited on a collection of
quantum systems at a rate that scales super-extensively. Some of these schemes
for `quantum batteries' rely on the use of global many-body interactions that
take the batteries through a correlated short cut in state space. Here, we
extend the notion of a quantum battery from a collection of a priori isolated
systems to a many-body quantum system with intrinsic interactions.
Specifically, we consider a one-dimensional spin chain with physically
realistic two-body interactions. We find that the spin-spin interactions can
yield an advantage in charging power over the non-interacting case, and we
demonstrate that this advantage can grow super-extensively when the
interactions are long ranged. However, we show that, unlike in previous work,
this advantage is a mean-field interaction effect that does not involve
correlations and that relies on the interactions being intrinsic to the
battery.
