How To Easily Remove, Install & Replace an Apple iPhone 4S Battery - YouTube
Looking inside an iPhone 4/4S battery | Rip It Apart - Jason's electronics blog-thingy
Teardown of Apple's iPhone 4S reveals larger battery, new baseband chip | AppleInsider
Original Battery for Apple iPhone 4 Mobile Battery with 6 Month Warranty and high Capacity Battery Backup.Carefully Check Your Phone Model and Purchase.(for iPhone 4) : Amazon.in: Electronics