Creating a custom power plan enables the user to manage power according to his/her own usage. A custom power plan can help in extending the standby time and usage time of your laptop. If you want to create it, here is how you can do in Windows 8:
1. Go to Control Panel
2. Click Power Options
3. Now click Create a power plan
4. Name your custom plan and select the type, e.g. Balanced (recommended), Power Saver, and High performance, and click Next.
5. Now change the settings for your plan by adjusting the display to set on or off on power and on battery, when to turn off the display and when to put the computer to sleep. When done, click Create
6. You would now see a custom power plan created and selected as shown in the options