Vista Dell E1505 Hibernation

Hello, Is is safe to just hibernate my vista laptop instead of turn it completly off on a consistent basis. I'm getting kind of tired of the slower startup performance but hibernating it solves the problem. Would this put some sort of strain on the computer itself or maybe the battery? On my older xp laptop I havent turned it completly off in years ( just hibernated it) unless i had to restart for an update or something like that. So is just leaving the computer in hibernation instead of shutting it off for the night a safe thing to do?