iPhone 17 Pro Max battery life test results are in — this blew us away

The iPhone 17's battery life matters to all users, and can be especially crucial for some. Nobody wants to be without their primary device when you need to send a message, make a payment or take a quick photo. And as the largest of Apple's new iPhones, the iPhone 17 Pro Max is responsible for carrying the flag when it comes to battery longevity.

With improved power efficiency from the A19 Pro chipset, and larger batteries, we have been hoping for Apple's already strong results with the iPhone 16 series to be even better this year. And to mix things up, we've done some other testing to give a fuller picture of how the latest Pro Max iPhone's battery lasts and refills during a typical day.

But how does the iPhone 17 Pro Max compare against Apple's previous best, or its biggest rival from the Android world? You're about to find out.

Battery life

This first test is the in-house TG battery test. In case you've not come across our testing before, this involves constantly cycling through a set of web pages over a cellular connection with the display at a set brightness. The phone then runs from 100% battery until it dies, at which point the test ends and gives us a result.

As well as the new iPhone 17 Pro Max, we have results from the iPhone 16 Pro Max, both our original set from launch last year, and a retest done at the same time as the 17 Pro Max. Plus, for some Android perspective on things, we have results from the Samsung Galaxy S25 Ultra, the closest rival to the new Pro Max.

As we can see, the iPhone 17 Pro Max has beaten the competition easily. It lasted three and a half hours longer than the Galaxy S25 Ultra, and about 20 minutes longer than the iPhone 16 Pro Max it's replacing.

Since we've held onto the iPhone 16 Pro Max since launch, we can see how the battery life has reduced after a year of use. It still reads as 100% healthy in the Settings app, but daily usage has still taken a toll.

YouTube test

In a second, less formal test, we played YouTube over Wi-Fi on these phones at 50% brightness for five hours to see how much battery percentage each phone lost. Unlike our official battery test, we were unable to have all phones set to an identical brightness level, but putting all at 50% should hopefully make for fairly even test conditions.

The iPhone 17 Pro Max wins this one too, but the gap between it and the Galaxy S25 Ultra and iPhone 16 Pro Max isn't that large. It shows that while Apple's latest flagship phone is the longest-lasting of the phones in this set we're testing, any of them should still easily last a full day without any trouble.

Charging

Batteries need charging, sooner or later, so we've also checked out the phones' refuelling speeds. For this, we used Apple's new 40W charger (with 60W peak output) to charge the iPhone 17 Pro Max, Apple's older 30W charger for the 16 Pro Max, and a 45W Samsung charger in the Galaxy's case.

Here we see Apple's only been able to overcome its historic charging speed weakness somewhat with its new charging tech. While both iPhones charge faster than the 50% in 30 minutes that Apple claims, both are still slower than the Galaxy S25 Ultra. The difference is only small at the 15-minute mark however, which weakens any bragging that Samsung owners may want to do.

Bottom line

So Apple has once again broken its previous record with the iPhone 17 Pro Max, offering an even longer-lasting iPhone. And while it doesn't match up to the Galaxy S25 Ultra's charging speeds, it's faster to fill up too.

As our best phone battery life rankings go though, this performance doesn't actually boost Apple's position. The iPhone 17 Pro Max will enter at number 7 - certainly a good score - but it's still behind the top performers on this list, like the Asus ROG Phone 9 Pro, which lasts over 20 hours on this test.

If you're curious about how the other new iPhones performed in this test, and more generally, check out our iPhone 17 review, iPhone 17 Pro review and iPhone Air review for the full lowdown.

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