  We characterize for the first time the performances of IBM quantum chips as
quantum batteries, specifically addressing the single-qubit Armonk processor.
By exploiting the Pulse access enabled to some of the IBM Quantum processors
via the Qiskit package, we investigate advantages and limitations of different
profiles for classical drives used to charge these miniaturized batteries,
establishing the optimal compromise between charging time and stored energy.
Moreover, we consider the role played by various possible initial conditions on
the functioning of the quantum batteries. As main result of our analysis, we
observe that unavoidable errors occurring in the initialization phase of the
qubit, which can be detrimental for quantum computing applications, only
marginally affects energy transfer and storage. This can lead
counter-intuitively to improvements of the performances. This is a strong
indication of the fact that IBM quantum devices are already in the proper range
of parameters to be considered as good and stable quantum batteries, comparable
to state of the art devices recently discussed in literature.
