Battery capacity is a crucial performance metric for quantum batteries, and the exploration of methods to enhance battery capacity is of great importance for practical application. We propose a memory-assisted battery model and demonstrate that the battery capacity can be improved by performing either projective measurements or general positive operator-valued measures on the memory. It is found that the maximum gain in battery capacity from projective measurements is linked to the presence of quantum correlations. For quantum-classical states, the maximum gain is attained by projective measurements. We further extend the framework to weak measurement, and prove that its performance cannot surpass that of projective measurement. However, under certain conditions, selective weak measurement could outperform projective measurement in enhancing battery capacity. These findings are illustrated in a two-qubit state, which serves as a concrete example to exhibit how measurement schemes can be chosen to optimize battery capacity.

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• Quantum correlations in quantum information
• Quantum information theory
• Quantum measurements
• Weak values & weak measurements