Battery Replacement Overview
You have a few options to approach iPhone battery replacement. The iPhone replacement service at Apple costs around $90 and is the most expensive. There are a variety of 3rd party vendors that charge anywhere between $40 - $60 for full service. The DIY kit purchased off the Internet will cost right around $20 and is the least expensive option.
If you feel comfortable opening your home PC and installing a Hard Drive then you should be able to perform an iPhone battery installation. Just follow the video instructions and use the whitepapers on this site as a reference. Whoever you purchase the battery from verify they have perfomed benchmark testing on the batteries. The benchmark tests should be open and available on their site. All of the battery vendors we have listed on this site have full battery benchmarks and some even include the suction cup to remove the touch screen glass (important). Don't go cheap on the battery and avoid using eBay because of quality control issues.
iPhone 3G vs. 3Gs
The iPhone battery replacement process for these two models is identical with one exception. The iPhone 3Gs has an additional connector near the dock that needs to be disconnected. The batteries between these two models only vary in capacity but the design is identical. These two batteries can be interchanged between the two models keeping in mind the slight difference in capacity. The iPhone 3G has 1150 mAh capacity and the 3Gs is 1219 mAh.
iPhone Original (2G)
The iPhone battery replacement process for the iPhone original is difficult. The case tolerance on this model is very tight resulting in a challenging disassembly process. Expect some bending and flexing of the case and potential minor damage when removing the case. Also, because of the poor service design on this model about 20% of the units will experience some issue during the replacement process. Most service companies will not work on this model because of these issues. This model also requires a soldering iron during the battery replacement process.
