What value should the crew use when determining battery duration on each BUS?

When determining battery duration on each BUS, the crew should use the shorter duration of either BUS 1 or BUS 2. This approach is correct because the overall system can only run as long as the component with the least capacity allows. If one BUS has a significantly shorter battery life than the other, relying on the shorter duration ensures that the crew is prepared for the worst-case scenario. This conservative strategy helps to avoid situations where the longer-lasting BUS is drained while the other is not monitored closely enough, potentially leading to operational failures or safety risks.

In scenarios involving redundant systems such as BUS 1 and BUS 2, it's vital to understand that in critical operational environments, the performance of the system is influenced by its weakest link. Therefore, preparing for the shorter duration is essential for ensuring mission success and safety.