I've seen the battery percentage on my 3GS jump from 70% to 40%, 65% to 59%, etc. Is it normal? I running 3.1.2 because it's jailbroken and I can't really be bothered to do a full restore then set everything up again afterwards (plus lose all my gamesaves etc.) But surely it shouldn't be jumping around like that? I don't think I'm running anything battery intensive.