I've had this phone for about a month and I just ordered one for my wife. It just arrived at home as she was headed out so she didn't get the chance to charge it up. My question is, is it necessary to do a full charge before she starts playing with it? And if so, how long does a full charge take? If she doesn't do a full charge, will it negatively effect future battery life? Thanks. She's not using it now but I know she's going to want to as soon as she gets home!