How does the system notify the user that the power module needs changing?

The system notifies the user that the power module needs changing by emitting an audible tone and displaying an empty battery icon. This dual method of notification is effective for ensuring that the user receives both a visual and an auditory signal, which is crucial in emergency situations where visibility may be compromised and quick action is essential. The empty battery icon serves as a clear visual indicator that the power module's capacity is low, while the audible tone captures attention, regardless of where the user is focused. This redundancy helps prevent potential misunderstandings or overlooked notifications, ensuring safety and reliability in critical environments where SCBA may be used.