iPhone 16 Pro Max offers ‘best battery life on iPhone ever’ — how much better is it?

iPhone 16 Pro Max display
(Image credit: Future)

When it comes to battery life and the new iPhone, Apple is making a pretty big claim. 

During the tech giant's huge Glowtime event on September 9, the company announced the iPhone 16 Pro lineup, saying that the iPhone 16 Pro Max in particular boasts "the best battery life on iPhone ever."

Will this be enough to put more than just the iPhone 15 Plus on our best phone battery life list? Maybe. Read on to see what we can extrapolate from information that Apple has released about the iPhone 16 series and how it compares to what we already know about last year's iPhone 15 lineup. 

iPhone 15 and 15 Plus vs. iPhone 16 and 16 Plus

All four phones have slightly different sized batteries, increasing in size as we go up in phone tier. That said, we can group the non-Pro models versus Pro variants as they will feature different versions of the newly announced A18 chipset. Of course, the Pro and Pro Max get the A18 Pro and last year's versions had the A17 Pro processor. While the iPhone 16 and 16 Plus skipped the A17 and jumped straight to the A18.

Again, Apple does not release the battery size of their phone, but Tom's Guide extensively tests every device that comes across our desk. And you can find out the size of the battery from regulatory listings and teardowns.

Via regulatory listings we found that the iPhone 15 and iPhone 15 Plus have 3,349 mAh and 4,383 mAh batteries, respectively. In our tests we found the Plus model performed much better than the standard iPhone 15, giving us a battery life of 14 hours and 14 minutes compared to 11 hours and 5 minutes. 

We won't know for sure what the iPhone 16 and 16 Plus will get until we can fully test the handsets.

For now, we can look at the video and audio playback numbers that Apple claims in their technical specifications.

Swipe to scroll horizontally
Header Cell - Column 0 iPhone 15iPhone 16iPhone 15 PlusiPhone 16 Plus
Video playback20 hours22 hours26 hours27 hours
Video playback (streamed)16 hours18 hours20 hours24 hours
Audio playback80 hours80 hours100 hours100 hours

As you can see, the iPhone 16 barely has more life than the iPhone 15 with 22 hours of video playback compared to 20 hours in the 15. The Plus only fares marginally better with only one extra hour of video playback, though it does get a couple more in streamed playback. 

Audio remains the same for both models.

Typically, newer processors are more energy efficient than the previous generation.  We do wonder if introducing Apple Intelligence to the phones will reduce the battery life since on-device AI tends to require more power to run. If so, we might see battery life that is similar to the iPhone 15 series rather than surpassing it.

The A18 chip has a 6-core CPU that's supposed to be 30% faster than the A16 in the iPhone 15. Apple claims that it is more energy efficient, utilizing 30% less power while providing equal performance. The GPU is supposed to be 35% more efficient.

iPhone 15 Pro and 15 Pro Max vs. iPhone 16 Pro and 16 Pro Max

Specifically with the iPhone 16 Pro models, Apple is promising the best battery life ever for an iPhone, which is good since the iPhone 15 Pro models had weaker battery life. 

The Pro models will get the A18 Pro chipset, which Apple claims is 20% more power efficient than last year's A17 Pro chip.

Based on regulatory listings, we found that the iPhone 15 Pro featured a 3,274 mAh battery while the Pro Max came with a 4,422 mAh battery.

The iPhone 15 Plus had the best battery life of the four phones in our tests offering 14 hours and 14 minutes of battery life. The 15 Pro was the weakest, only getting to 10 hours and 53 minutes of battery life. The 15 Pro Max came in a bit closer to the Plus clocking in at 14 hours and 2 minutes. 

So, based on playback numbers, how much can we guess the iPhone 16 Pro models will best their predecessors?

Swipe to scroll horizontally
Header Cell - Column 0 iPhone 15 ProiPhone 16 ProiPhone 15 Pro MaxiPhone 16 Pro Max
Video playback23 hours27 hours29 hours33 hours
Video playback (streamed)20 hours22 hours25 hours29 hours
Audio playback75 hours85 hours95 hours105 hours

The iPhone 16 Pro models do appear better but only a little bit in some categories, but the Pro Max does seem to have more consistent improvement.

Both phones added 10 hours of audio playback compared to the iPhone 15 Pro models. In streaming video playback the 16 Pro is rated a couple hours longer than 15 Pro, while the 16 Pro Max adds four hours. 

Standard video playback saw a bit bigger leap with both 16 Pro models adding 4 hours.

iPhone 16 series battery: Outlook

These days most flagship phones are running closer to 5,000 mAh sized batteries and getting good battery life out of them. Though the implementation of AI and it's power needs is going to truly test how long these batteries can last.

For comparison, the recently released Google Pixel 9 Pro and it's larger brethen the Pixel 9 Pro XL feature batteries sized 4,700 mAh and 5,060 mAh, respectively. We tested the 9 Pro at 13 hours and 37 minutes, far better than the iPhone 15 Pro. 

With the marginal gains from the playback hours, we might see the iPhone 16 Pro underperform against the Pixel 9 Pro. 

Meanwhile, the larger Pixel 9 Pro XL managed 14 hours and 37 minutes in our testing — 35 minutes more than iPhone 15 Pro Max. Again, the 16 Pro Max appears to be better but will it be 35 minutes better? 

Keep it on Tom's Guide for all of the latest Apple news and we'll let you know how the iPhone 16 lineup actually fares once we run it through our gamut of tests. Read our guide if you want to know how we test smartphones and we what we use to determine performance, battery life and more.

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Scott Younker
West Coast Reporter

Scott Younker is the West Coast Reporter at Tom’s Guide. He covers all the lastest tech news. He’s been involved in tech since 2011 at various outlets and is on an ongoing hunt to build the easiest to use home media system. When not writing about the latest devices, you are more than welcome to discuss board games or disc golf with him.