Installing a new battery also means users must expect a three-day wait and should be prepared for all the data on their phone — including contacts, e-mail account settings, text messages and other content — to be wiped out. Source: InfoWorld
Remember that Apple estimates 300 - 400 charges for a battery. This means for many heavy users, about a year or less. The cost is $85.95 including shipping, BTW. But this “losing all your data” when the battery is changed? That went out with old Treos a long time ago. I can’t believe that they would lose all the data when changing the battery … perhaps it’s just a caution to the end user … but still.