Testing the Realme P4 Power: Can It Serve as an Effective Power Bank for Your iPhone?

The Realme P4 Power was launched earlier this week, boasting an impressive 10,001mAh battery. Realme highlights its comparison to a standard 10,000mAh power bank, noting that the P4 Power is 43% thinner (9.08mm) and 14% lighter (219g). This raises the question: can the P4 Power actually function as a power bank? We decided to find out.

For our test, we began with a fully charged Realme P4 Power and a nearly depleted iPhone 17 Pro, which had only 7% battery remaining. We connected the two devices using a USB C-to-C cable and a measurement device to track the charging speed in real time.

Initially, the Realme P4 Power delivered 22W to the iPhone. It’s important to note that for optimal reverse charging speeds, the screen of the P4 Power must be off, as it otherwise reserves power for its operation.

After 10 minutes, the charging speed decreased slightly to 19W, with the iPhone 17 Pro reaching 23% battery. The Realme P4 Power still had 94% remaining. You can see the reverse charging in action in our video here.

At the 30-minute mark, the charging speed dropped further to 11W, and the iPhone reached 48%. The P4 Power was at 80% battery. This scenario is likely reflective of real-world usage, such as topping up a friend’s phone for 10-30 minutes. At this level, the iPhone user would have enough battery to last through the day.

Curiosity led us to continue the test. After 50 minutes, the iPhone charged to 65% (at a power of 9W), while the Realme dropped to 70%. We concluded the test after 70 minutes, when the charging rate decreased to 7W. At this point, the iPhone had reached 70%, and the Realme’s battery level was down to 61%.

Test timeline: start • 30 minutes in • end at 70 minutes

For comparison, in our review of the iPhone 17 Pro, we utilized a 45W Pixel AVS charger, which achieved 70% in 30 minutes and completed a full charge in 1 hour and 18 minutes. It’s worth noting that most phones don’t support AVS as input, and Realme claims the P4 Power can achieve a maximum reverse charging power of 27W. Our testing device indicated that both phones established a USB PD connection at 9V and up to 3A.

The results are telling: the Realme P4 Power can completely charge an iPhone 17 Pro once. While one might assume that it could do this twice based on battery capacities alone, conversion losses prevent it from achieving that goal.

In any case, we believe that a 10-30 minute quick charge is what most users are likely to perform. Furthermore, even if you were to charge your friend's iPhone to 100%, you would still have enough power in the P4 Power for several hours of gaming before returning home.

Lastly, there is the consideration of how quickly the Realme P4 Power charges itself. With 80W SuperVOOC charging, Realme asserts it can reach 0-50% in just 36 minutes. This is something we intend to test in the near future.