20 - 30 minutos
Battery had to be charged 2x a day. Majority of the time, my phone would shut off around the 50-60% mark, and when I tried to power it back on, it'll stay at the apple logo and shut off again. The only way it would power back on to the springboard, is if I connected it to a charger.
It went extremely well. The guide was a bit cumbersome. My camera had detached off of the motherboard and iFixIt didn't mention anything about the camera being able to come off and putting the motherboard back into the casing was a nuisance because I had no idea there were little sockets to keep the motherboard in place.
Read the article about how to change the battery. Don't just watch the video. And I advise you read it first before attempting to change the battery.