Tech Chap Runs the iPhone 18 Pro and Pro Max Until the Screens Go Dark

Fresh iPhone 17 and iPhone Air owners are already asking the same thing. If battery is the only reason to spend more, do the new iPhone 18 Pro and iPhone 18 Pro Max actually earn the upgrade. Tech Chap tried to answer that by running those two new Pros against last year’s 17, 17 Pro, 17 Pro Max, and the thin iPhone Air until every phone died, then he ran the whole thing a second time with a Galaxy S26 Ultra in the mix.

Each phone in the room was a worldwide model with a removable SIM tray. The North American eSIM-only variants have somewhat larger batteries, about 6% more on the 18 Pro and 4% more on the 18 Pro Max, so they should last a little longer, but we won’t see those results here. Tech Chap had purchased new units, ensured that the battery health was 100%, completed all of Siri’s indexing, and upgraded them all to the latest iOS 27 release. He mixed up the drain by using cellular data, video recording, on-phone video editing, regular web surfing and app usage, and occasional gaming. He utilized an iPhone 13 mini as the timer to avoid any timing concerns with the phone itself.

The iPhone Air went first, lasting approximately 7 hours and 10 minutes. The iPhone 17 was about 30 minutes behind, which was an acceptable performance given the price differential, even after the new phones were released. The iPhone 17 Pro took another 10 minutes to catch up to the 17, and then shut down at 4 or 5 percent charge when the cheaper phone ran out of juice. That was a tight stretch, but the iPhone 17 Pro Max still had more than 20% charge when the Air died. The new iPhone 18 Pro reached 7 percent charge before last year’s 17 Pro died, providing an additional 45 minutes of runtime in that portion of the test. Apple had stated that the 18 Pro should be comparable to last year’s 17 Pro Max. In this physical SIM test, however, last year’s Pro Max maintained a significant lead.

The iPhone 17 Pro Max died just after 10.35 hours. The iPhone 18 Pro Max still had 8 percent charge and lasted another 45 minutes before dying, bringing the total time to 11 hours. The relative increases appeared to be similar across both sizes: 17 Pro to 18 Pro and 17 Pro Max to 18 Pro Max. You could sense the improvement, but it wasn’t a great leap. A second run was completed for good measure. The Air died four minutes earlier than before, at 7 hours. The iPhone 17 lasted around 8 minutes longer than the first time. The iPhone 17 Pro was barely 3 minutes off its previous time. The iPhone 18 Pro had a 5% charge when the 17 Pro died and lasted 8 hours 35 minutes, coming within 10 percentage points of last year’s Pro Max without actually catching up. For comparison, the Galaxy S26 Ultra, which was around 8 months old at the time, died after just 9 hours. The iPhone 17 Pro Max lasted 10 hours and 11 minutes, whereas the iPhone 18 Pro Max was still 11% charged when the older Pro Max died.

Bigger cells always seemed to come out on top, as the Pro Max phones just kept going compared to the rest, and Tech Chap summed it up quite well by noting the major reason to pay more for the larger body is that they simply last a lot longer. However, the Air to 17 is a significant step up, as is the Pro to new Pro from one year to the next, and last year’s Pro Max appears to be able to compete with this year’s smaller 18 Pro, at least on our worldwide SIMS and the mix of work I’ve been doing.

Let’s be honest, once you start adding all the variables together, signal strength, screen brightness, and which apps you end up utilizing, it’s a marvel his statistics don’t vanish totally, giving you a true image of battery life rather than a rosy promise for every situation. If battery life alone was enough to persuade you to go with a new 17 or Air, the 18 Pro Max is the phone that keeps going long after everything else has shut down.