New stable quantum batteries can reliably store energy into electromagnetic fields

https://phys.org/news/2022-08-stable-quantum-batteries-reliably-energy.html

"electromagnetic field reaches steady state, whose energy can be determined and decided a priori when building the micromaser. This property ensures protection from the risks of overcharging... final configuration electromagnetic field pure state... no memory of qubits used during charging... all energy stored extracted and used... without the need of keeping track of the qubits used during charging process... robust and not destroyed by changing specific parameters"