Using the Realme P4 Power as a Power Bank for Your iPhone: Performance Test

The Realme P4 Power was unveiled earlier this week, boasting a remarkable 10,001mAh battery. According to Realme's promotional materials, the phone is 43% thinner than a typical 10,000mAh power bank at 9.08mm thickness and 14% lighter at 219g. But can the P4 Power function as a power bank? We conducted a test to find out.

We began with a fully charged Realme P4 Power and an iPhone 17 Pro that was nearly out of battery, sitting at only 7%. We linked the two devices using a USB C-to-C cable and employed a device to measure the charging speed in real time.

Initially, the Realme P4 Power delivered 22W to the iPhone. It’s important to note that to achieve maximum reverse charging speeds, the screen of the P4 Power needs to be off, as having it on consumes power for its own operations.

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

After 30 minutes, the charging speed dropped to 11W. At this point, the iPhone had reached 48%, and the Realme was at 80% battery. This scenario closely resembles real-world usage, such as when a friend asks to borrow some charge for 10-30 minutes. With 48%, the iPhone user could carry on for the rest of the day—a successful charge.

Out of curiosity, we continued the test. After 50 minutes, the iPhone battery was at 65% (with charging power reducing to 9W) and the Realme P4 Power was at 70%. The test concluded after 70 minutes, with charging power further declining to 7W, resulting in the iPhone’s battery reaching 70% and the Realme’s battery down to 61%.

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

For context, in our review of the iPhone 17 Pro, we used a 45W Pixel AVS charger, which charged the iPhone to 70% in 30 minutes and completed a full charge within 1 hour and 18 minutes. While it’s worth noting that many phones do not support AVS as input, Realme advertises a maximum reverse charging power of 27W. According to our test device, the two phones negotiated USB PD at 9V and up to 3A.

The results highlight that the Realme P4 Power can fully charge an iPhone 17 Pro once. Although it may seem that it has enough capacity to charge it twice, conversion losses mean it just falls short.

Regardless, a 10-30 minute charge is likely what most users would utilize it for. Impressively, even if you were to fully charge a friend’s iPhone, the P4 Power would still have sufficient battery to support hours of gaming until you make it back home.

Finally, we must consider how quickly the Realme P4 Power itself recharges. With 80W SuperVOOC charging capabilities, Realme claims that it can achieve 0-50% in just 36 minutes. This is a performance metric we will be testing ourselves.