Serge is frustrated because his Samsung Galaxy S3 is getting hot and only getting about an hour and a half of battery life.
Leo says that's likely a runaway process that's eating it away. Facebook is notorious for this. Leo recommends turning off automatic updates on Facebook. He should also install G-Sam Battery monitor, which will show him what programs are running and killing battery life. Android 4.3 is going to offer a fix that will group all apps that need updating and then wake the phone to update.