20 - 30 minuten
iPhone 3GS was not holding much of a charge. In fact, many days it required multiple charges.
Great! Instructions were clear and easy to follow. My only trouble was with getting the battery removed from the back cover. I wish either ifixit had a little more help as far as ideas for removal but i understand that Apple really is the one to blame here for design.
I will find a way to properly dispose of this battery but I would love it if ifixit would add that element in to the repair process. I would be happy to pay for a service like that. Overall, i really enjoyed using ifixit! Keep it up, knowledge is power.