How do I replace the battery in the iPhone 4 and iPhone 4S?

Like all previous iPhone models, the battery in both of the iPhone 4 models -- the iPhone 4 (GSM) and iPhone 4 (CDMA) -- as well as the iPhone 4S is not intended to be upgraded by an end-user. When the battery reaches the end of its useful life, Apple intends for one to return the entire device to the company to have the battery replaced for a cost of US$79 plus US$6.95 shipping (and applicable sales tax).

However, more affordable third-party services also are available and for those with some technical skills, self-replacement is quite possible, too.

Identification Help

If you are not certain which iPhone model you have, each iPhone can be externally identified by a unique model number listed on the back of the phone toward the bottom. The iPhone 4 (GSM) -- intended for use on AT&T in the US -- and the subsequently released iPhone 4 (CDMA) -- intended for use on Verizon or Sprint in the US -- are model number A1332 and A1349, respectively. The iPhone 4S is model number A1387.

The iPhone 4 and iPhone 4S models also can be differentiated by the last three characters or four characters of the serial number with EveryiPhone.com's Ultimate iLookup (the last three characters if it has an eleven character serial number and the last four characters if it has a twelve character serial number). The serial number is not externally listed, but it is available when plugged into a computer on the "Summary" tab in iTunes.

In addition to the last three or four characters of its serial number, EveryiPhone.com's Ultimate iLookup feature can identify the iPhone models by EMC number and order number (referred to as "Model" from within the iOS), as well.

Battery Replacement Video Instructions

The battery in the iPhone 4 (GSM), iPhone 4 (CDMA), and iPhone 4S is attached with adhesive, like earlier iPhone models. However, unlike previous iPhone models, the connector is not soldered and it is relatively easy to replace.

It's much easier to open the case on these models than earlier iPhone models, too. Regardless, professional installation still is recommended.

Nevertheless, for those willing to tinker, PowerBookMedic provides a video that can be used to replace the battery in the iPhone 4 models:

Although the procedure is nearly identical to the iPhone 4 -- it essentially involves unscrewing two internal screws rather than one -- iFixit provides directions to replace the battery in the iPhone 4S, specifically.

From watching the video or reviewing the step-by-step instructions, you should be able to determine whether or not you feel comfortable replacing the battery yourself or if you would instead prefer to hire a professional.

Site sponsor Mission Repair offers free iPhone hardware diagnosis and a professional 24-hour iPhone 4 battery replacement service by mail in addition to inexpensive "do it yourself" battery replacement kits.

Also see:

• How do I replace the battery in the original iPhone (2G)?
• How do I replace the battery in the iPhone 3G and 3GS?