When browsing the Joomla! backend you may have noticed that after a certain amount of idle time Joomla! will ask you to log in again. By default, Joomla! kicks you out when you've been logged in for 15 minutes without any activity. When developing a site it can be quite annoying to have to log in every time you return to your desk with a fresh cup of coffee. Let's change this with the Session Lifetime setting in the Joomla! preferences.
1. From the Control Panel, navigate to Site | Global Configuration (you can also click on the Global Configuration button below the menu bar; it's a shortcut).
2. Global Configuration is divided into Site settings, System settings, and Server settings. Click on the System link to show the appropriate settings panel.
3. On the System page, you'll see Session Settings in the bottom-right corner. Change Session Lifetime to 45 minutes.
4. Click on Save. From now on you can leave the computer for 45 minutes before Joomla!...