5 - 30 minutos
I had a defective third party iPhone battery and didn't initially want to shell out extra for a "premium" battery.
After taking the plunge and buying the ifixit battery, installation was a breeze, and the problem I was having is now gone.
Buy this battery. It is a great quality product. If you are suffering from constant reboots/shutdowns, or just very poor battery longevity, this battery is the solution.