That depends on your iPhone model, take iPhone X (Battery Capacity: 2716mAh) for instance.
POWER CUBE X can supply iPhone X 1.5 times charge. What more important is the SMART DOCK is perfectly designed to fit POWER CUBE X as a operating charging station that makes recharging a lot easier and it perfectly to prevent users from forgetting to recharge their Power Bank. Besides, you can charge your iPhone and POWER CUBE X at the same time. With your POWER CUBE X, your phone is always in charged.