Is there a solution for the battery drain problem that the note 2 suffers after the 4.3 update? In my case the drain is most noticeable when the wifi is on. When its off battery lasts a good while same or maybe a little bit better than before. But when wifi is enabled, you can watch the battery indicator change values quickly. I've looked for solutions but found non that seems to be working.
There may be apps in the background that run which drains the battery life. To be certain of which app: Go to
Settings > Battery > Battery Graph
The battery graph will give detailed analysis which app used how much battery. If there is any app that you don't recall using a lot but is one of the top battery consumers I'd recommend you to uninstall/disable the said app.