The iPhone 15 has shown incompatibilities with several power banks, leading to issues where the device does not draw power from these packs. Instead, it appears to push energy back into external batteries. This observation comes from user feedback summarized by MacRumors, which notes that a subset of USB-C power banks fail to deliver charging to the iPhone 15 and may even induce reverse charging in practical use.
Across user reviews, the pattern is clear: compatibility extends beyond simple connector compatibility. Not every USB-C power bank works seamlessly with the iPhone 15. In some scenarios, the phone either remains uncharged when plugged into a power bank or begins transferring its stored energy to the charger bank. MacRumors highlights the possibility that the root cause lies with the iPhone 15’s reverse charging function, which may not activate reliably with certain accessories or firmware conditions.
Multiple power bank models have been implicated in these reports. In particular, the Anker PowerCore Slim 10K PD has been singled out by users for inconsistent behavior. Anker has issued a public response stating that the iPhone can be charged correctly only when using the USB-A port on that model. This guidance suggests that, for this specific pack, the USB-C PD pathway does not reliably support iPhone 15 charging as a power source, prompting a fallback to older USB-A-based charging in practice.
MacRumors notes that it is not feasible to assemble a definitive, exhaustive list of compatible or incompatible accessories given the sheer and ever-changing landscape of power banks on the market. The problem is not isolated to a single brand or design; it spans a broad spectrum of devices that rely on USB-C for fast charging or power delivery. For users, this means that after purchasing a power bank, a quick real-world test with the iPhone 15 is prudent to confirm whether charging works as expected, and if not, to try alternative ports or devices to identify a usable configuration.
As context, earlier hardware demonstrations and independent testing have indicated broader performance differences between iPhone 15 bases and premium variants. Reports from testing channels note that the base iPhone 15 and iPhone 15 Plus can exhibit higher charging demands under some conditions than the titanium iPhone 15 Pro and 15 Pro Max. While these comparisons often focus on battery health and efficiency, they underscore how charging behavior can vary across iPhone models and influence compatibility outcomes with external power sources, including high-capacity packs and multi-port hubs.