So, I have an older model, but it should be really similar... First, try disabling any apps you never use - Settings, Applications, Application Manager - go through and click perhaps something like Polaris Office, and click disable. A quick fix after running a lot of apps may be to simply restart your phone. Check Power Saving Mode, as well, if you are going to not use your phone for several hours. The settings can be adjusted for that, too, I believe.
