While using your Kindle Fire, it can be annoying when the screen shuts off too soon. Or if you want to save battery juice, you can enable it for as little as 30 seconds. Here’s how.
From the Kindle Fire main screen, tap the Settings icon then the More button.
On the Settings screen tap Display.
Now, tap Screen Timeout. It’s set to five minutes by default.
Now select the length of time you want to pass before the screen times out. You can select from 30 seconds to Never.
I’ve found that increasing the Screen Timeout is helpful when it’s plugged into your system while rooting the tablet.