A beta is not a trial version for nothing and thus it includes serious errors, among other things, the battery life but also heat problems. If it's really that bad, I would recommend getting out of the beta and switching your device to the public version via the MacBook or Apple Store. Most of all, the Beta 7-8 are the really most stable versions and run better but above all the RC.
Topic:
Community
SubTopic:
Apple Developers
Tags: