I'm guessing the resale of my 3G 16GB is going to drop with the new pricing on the 3G models. So I'm thinking of just keeping it around in case I somehow lose or damage the new phone (or one of my family members does their 3G in). If the old phone is "off" and not in use would charging it one a month help the battery? Is the phone really ever "off" or is it on standby?