I got a certified pre-owned Blackberry Bold last Friday, and I've been very happy with it. The only problem is the battery life. I charge it for about seven hours overnight, but after about four or five hours of minimal use, the battery is almost dead. I rarely make calls and only text, check Facebook, and BBM a few times an hour. I turned off the WiFi today and that seems to have helped a little bit, but what else can I do to extend the battery life?