NewerTech® : Batteries : NuPower® Battery Replacement Service for Apple® iPhone® 3GS
Expanded iPhone 3GS Battery | iPhone Repairs
Apple iPhone 3GS A1303 Battery Replacement Kit with Tools, Video Instructions, Extended Life Battery and Full One Year Warranty - Walmart.com
How to replace the iPhone 3G or 3GS battery | iMore
How to replace the iPhone 3G or 3GS battery | iMore
I was planning to use my old iPhone 3GS for weekend project but I discovered that the screen was popped out and the back was bulging, I took it apart and this