Hi! Sorry to hear that you're experiencing crashes. If you can email me a copy of a game log from a play session that included a crash, one of the saves that the game has crashed while loading, and your system specs to the email address listed under the technical support section here on the store page, I'll be able to dig in and take a look.
I might not be able to do much about battery performance, but I've got some ideas to try and can give you a link to a test build once I've got some more details.