While Apple touts 7-9 hour battery lives for its various portable products, MacBook owners will know that sometimes this simply is not the case. Even though you might not be doing any active work in power-hungry programs, you might see your battery life plummet and only last a couple of hours at most.

If this happens, then there are several things you can do, with one quick option being to check on what possible programs you have running that might be drawing excessive energy from your Mac. This is available in several areas in OS X:

The Battery Menu

For OS X Mavericks users, you have the option in the battery menu to see what applications you have open that are using excessive energy. If you select any application that shows in this menu, OS X will open the Activity Monitor utility with this program selected, so you can better monitor how it is running, or force-quit it, if necessary.

Activity Monitor

While desktop applications you open will show in the Battery menu if they are using energy, only people using OS X Mavericks or later will have this option. Even if you are using Mavericks, there may be background tasks running that can get stuck using excessive energy, and not be reported in the Battery menu. Therefore, even if the Battery menu shows no applications using excessive energy, open Activity Monitor anyway and check for the following details (be sure you have all processes shown, and not just applications or user processes shown):

1. In the CPU tab, sort all programs by the %CPU column, and watch this to see if any regularly use a high percentage of the CPU. If so, then they may be worth looking into.
2. In the Energy tab, sort all processes by the Energy Impact column, and again look into any programs or processes that are at the top of the list.
3. In the Memory tab, do the same and see if any programs are using excessive memory. While a large memory footprint is not always indicative of a process being energy-hungry, it can suggest a program has a memory leak, or is otherwise not functioning correctly and may be a possible culprit. In determining this, consider excess usage to be many gigabytes of memory, especially when you have paused these programs’ routines and closed any documents they have open.
4. Similar to the above options, consider investigating disk activity in the Disk tab of Activity Monitor, where you can see what programs are regularly reading from and writing to the disk. As with the other metrics, you can sort the columns in this view by bytes written or read from disk, and see if they are increasing for any program more than others. If so, then especially if your Mac uses a conventional hard drive, you might consider investigating this process to determine why it is using the drive.