Apple's next Pro-model iPhone could end up having the biggest battery ever released in an iPhone, surpassing even the 5,088mAh capacity unit in the eSIM-only version of the iPhone 17 Pro Max. According to a fresh round of rumors, the iPhone 18 Pro Max in nano SIM form could bump that up to 5,235mAh, while the battery in the eSIM-only version is claimed to check in at 5,425mAh.

Battery capacity upgrades are not unusual, though at the same time, we shouldn't always take for granted that a new generation model will see a bump. It normally happens, though not always. For example, the iPhone 14 Pro Max debuted with a 4,323mAh battery compared to 4,352 in the iPhone 13 Pro Max.

Since then, however, every iPhone Pro Max has come with a bigger battery than the previous flagship. In reverse order, we're looking at 5,088mAh (eSIM-only) and 4,823mAh (nano SIM) for the iPhone 17 Pro Max, 4,685mAh for the iPhone 16 Pro Max, and 4,441mAh for the iPhone 14 Pro Max.

So where would a 5,235mAh battery capacity rank among smartphones? It's certainly impressive and beats what is found in Samsung's Galaxy S26 Ultra, though it's not at the top. Some examples: