20 - 30 minutos
When it appeared as though the battery was no longer working in my daughter's old iPhone, which she was letting her daughter play with to watch videos and games, I decided to try and replace the battery.
I had some previous experience using the iFixit site and instructions to replace the battery in an iPod and the repair on this iPhone went just as smoothly. From start to finish, I spend about 50 minutes.
My only difficulty was peeling back the sticker marked Do Not Remove without it tearing apart. Upon reinstalling, I used a small piece of plastic tape to cover the torn-up sticker. I think this is necessary to isolate and keep the circuit board from touching the screw head that the tape is supposed to cover.
NOTE: Caution should be stressed when working with Lithium Ion batteries, especially when found in the condition that I found in this iPhone. Obviously something went wrong with this battery. But fortunately, the battery casing was not punctured, which could have led to a fire. The smallest hole in the outer covering can cause the battery to burst into flames! Use extreme caution when prying the old battery from the back case, especially when found looking like mine did. I might note that the expansion of the old battery was enough to make the back case of the phone bulge and actually had several stress cracks.
Also...DO NOT throw the old battery in the trash. Ideal conditions could cause an unexpected fire! Instead, be careful to dispose of it in an approved manner. Most of the local home improvement stores will accept the old battery for disposal.