In the abstract of [Phys. Rev. Lett. 125, 040601 (2020)PRLTAO0031-900710.1103/PhysRevLett.125.040601] one can read that "[…] to have a nonzero rate of change of the extractable work, the state ρ_{W} of the battery cannot be an eigenstate of a 'free energy operator,' defined by F≡H_{W}+β^{-1}log(ρ_{W}), where H_{W} is the Hamiltonian of the battery and β is the inverse temperature […]." Contrarily to what is presented below Eq. (17) of the Letter, we observe that the above conclusion does not hold when the battery is subject to nonunitary dynamics.