Quantum batteries are a new class of energy storage devices that operate according to the principles of quantum physics. Quantum batteries have a counter-intuitive property in which the recharge time is inversely related to the battery capacity, that is the amount of stored electrical charge. This leads to the intriguing idea that the charging power of quantum batteries is super-extensive, meaning that it increases faster with battery size. The fabricated device is a microcavity in which the active material consists of organic molecules dispersed in an inert matrix. Each molecule represents a unit that can exist in a quantum superposition state of two energy levels (fundamental and excited). By constructing the quantum battery in a way that units can exist in superposition, the total system can behave collectively. This behaviour, known as quantum coherence, allows the units to act cooperatively, giving rise to a hyper-fast charge that depends on the number of molecule-units.