Apple has revealed details of its battery replacement plan for the iPhone.

The plan costs US$79 plus an additional $6.95 postage and packing. Under the plan, iPhone users will be able to have their battery replaced if it fails, the plan extends to devices that have passed their warranty period.

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, email account settings, text messages and other content -- to be wiped out.

"It is important to sync your iPhone with iTunes to back up your contacts, photos, email account settings, text messages, and more," Apple warns, saying it is, "not responsible for the loss of information while servicing your iPhone and does not offer any data transfer service."