5 - 30 мин.
Battery in iPhone 4 went bad. would not hold a charge.
Changed battery within 10 min, First time I ever opened a iPhone. Took my time.
Be sure to read and follow the instructions and get your parts from IFIXIT.COM. It was going to cost me $60.00 from BatteriesPlus. $24.95 for battery and tools. from you guys. Also thanks for the tools and screws to make the upgrade.