A MacBook application may finish a demanding export and then become quiet. A low reading now does not contradict a higher figure for the earlier session. Activity Monitor’s Energy view helps separate those time periods before you change the workflow.

Open Activity Monitor and select Energy while the relevant task is running. Note whether the MacBook is on battery or external power, which document or media job is active and whether the unusual runtime began during that work.

Read the columns as different evidence

Apple describes Energy Impact as a relative measure of current energy use: lower is better. It is not a direct watt reading. The 12 hr Power column, available on Mac laptops, shows average energy impact over the last twelve hours or since startup if that period is shorter.

An application can therefore rank differently in the two columns. Record the current task before interpreting a historical average. Restarting and immediately comparing the new average with yesterday’s full workday would compare different observation windows.

Other available columns provide context. Preventing Sleep indicates whether an application is preventing sleep, while App Nap describes its current App Nap state. Read these alongside the task rather than treating one label as proof of a fault.

Make a useful comparison

Choose one repeatable task, such as opening the same local project and performing the same export. Observe the Energy view during that task and again after it finishes. Keep display brightness, connected equipment and the basic workload as consistent as practical.

If an unnecessary application appears active, save its work and quit it normally before repeating the comparison. Avoid force-quitting unfamiliar processes to chase a lower number; that can interrupt work and remove useful context.

Write down both the observed behaviour and any change in runtime or responsiveness. A lower application reading is useful only if the required task still completes correctly.

Use this record for workload investigation. Energy Impact does not diagnose battery capacity, charging circuitry or physical damage. If the complaint is an unexpected shutdown or charging failure, retain those symptoms separately instead of treating the busiest application as the confirmed cause.

References: Apple: energy use in Activity Monitor.