Just installed a great little FREE app. With the highly improved battery of the NX80V, I feel I can afford to have my it stay on longer. This app lets you choose 5, 10, 15, 30, 1h, Always On. It works great on the NX80V, despite being an older app. Don't recommend using the "Always On" setting, but 10 minutes seems about right for me.
my favorite always on type application is cool DAs, which is easy to use because it is in the form of a DA and doesn't require that you go into a seperate application.