The iPhone 17 Pro Max has the longest battery life Apple has ever put in an iPhone. Apple rates it at up to 39 hours of video playback, more than any iPhone before it. But that headline number comes from a controlled lab test, so the real question is simpler: how long does it actually last in your hand?
The short answer is that it is still the longest-lasting iPhone you can buy, even if you will not see 39 hours in normal use. In independent lab testing it lasted about 18 hours of mixed active use, which is a full day for most people with room to spare.
What Apple promises
Apple lists two battery figures in Apple’s technical specifications for the iPhone 17 Pro Max: up to 39 hours of video playback and up to 35 hours of streamed video. Those are the highest figures Apple has quoted for any iPhone, and they beat the smaller iPhone 17 Pro, which is rated at up to 33 hours of video playback and 30 hours streamed.
Apple does not publish the battery size in milliamp-hours. Instead it rates its phones in hours, using a test that plays one downloaded video on a loop at fixed brightness. That makes the number repeatable, but it is also a gentle test: one video file, quiet radios, no notifications, no camera and no gaming.
The bigger battery fits because the phone itself is bigger. The 17 Pro Max has a 6.9-inch screen and a thicker aluminium unibody than the standard models, which leaves room for a larger cell. It runs on the A19 Pro chip with 12 GB of memory, and the chip’s efficiency is part of the reason the phone lasts as long as it does.
What independent tests found
In the real world, the numbers come down. GSMArena’s lab testing put the iPhone 17 Pro Max at about 25.5 hours of looping video, rather than Apple’s 39, and its blended Active Use score, which mixes browsing, video, gaming and calls, came out at just under 18 hours.
That gap is normal, and it is not a sign that Apple is misleading anyone. Apple’s test and the lab test simply measure different things. A phone that streams video over 5G, takes photos, plays games and runs maps all day will always drain faster than one playing a single downloaded video on a loop.
What matters is where the phone sits next to other phones. By the same lab’s measure, the standard iPhone 17 managed about 15 hours of active use, so the Pro Max gives you roughly three extra hours over the base model. That is the difference between ending the day with charge to spare and reaching for a charger in the evening.
How it compares with the rest of the iPhone 17 line
Apple’s own ratings make the pecking order clear. The iPhone 17 is rated at up to 30 hours of video playback, the iPhone 17 Pro at up to 33 hours, and the iPhone 17 Pro Max at up to 39 hours. Streamed video drops each figure by three to five hours, to 27, 30 and 35 hours.
If battery life is your main reason for choosing a phone, the Pro Max is the pick of the range. The trade-off is size and price: you are carrying the biggest iPhone Apple makes, and paying the most for it.
Charging speed
The Pro Max charges fast enough that a short top-up is genuinely useful. Apple says it reaches about 50 percent in 20 minutes with a 40W or higher USB-C adapter, or about 50 percent in 30 minutes on a 30W MagSafe charger. If you charge overnight, speed matters less, but a 20-minute charge while you get ready in the morning can add hours of use. Our guide to wireless iPhone chargers covers the MagSafe and wireless options that work with it.
Should you still buy one?
Apple launched the iPhone 18 Pro on 9 September 2026, and stopped selling the iPhone 17 Pro models itself the same day. That makes the 17 Pro Max a previous-generation phone, but it is still widely sold by carriers and retailers, often at a discount, and it remains the longest-lasting iPhone of its generation.
The new iPhone 18 Pro Max is rated even higher, at up to 45 hours of video playback, so buyers who want the absolute best battery life should look at the newer model. But if you find the 17 Pro Max at a good price, its battery is still excellent: a full day of heavy use, and often well into a second day with lighter use.
Apple applies the same generous battery thinking across its devices. In our AirPods Pro 3 review, the earbuds’ improved battery was one of the biggest upgrades, and the same pattern holds here: the headline feature is not the chip or the camera, it is simply lasting longer between charges.
How to make the battery last longer
A few settings make a real difference on any iPhone, including the 17 Pro Max:
- Turn on Low Power Mode when you are below 20 percent. It cuts background activity and mail fetch until you charge again.
- Lower the screen brightness, or leave auto-brightness on. The display is the biggest single drain on the battery.
- Check which apps use the most power in Settings, then switch off background refresh for the ones you rarely open.
- Use Wi-Fi where you can. A weak mobile signal makes the phone work harder and drains the battery faster.
- Keep the phone cool. Heat ages batteries, so avoid leaving it in direct sun or a hot car.
None of these steps will turn the Pro Max into a two-day phone on heavy use, but together they can add a useful hour or two to a long day.
FAQ
How long does the iPhone 17 Pro Max battery last in real use?
Apple rates it at up to 39 hours of video playback. In independent lab testing it managed about 18 hours of mixed active use, which means a full day of heavy use for most people.
Does the iPhone 17 Pro Max have the best iPhone battery life?
Of the iPhone 17 line, yes. It is rated at 39 hours of video playback against 33 hours for the iPhone 17 Pro and 30 hours for the standard iPhone 17. The newer iPhone 18 Pro Max is rated higher, at 45 hours.
How fast does the iPhone 17 Pro Max charge?
Apple says it reaches about 50 percent in 20 minutes with a 40W or higher USB-C adapter, or about 50 percent in 30 minutes with a 30W MagSafe charger.
Is the iPhone 17 Pro Max still worth buying?
Yes, at the right price. Apple no longer sells it directly, but carriers and retailers still stock it, and its battery life remains excellent even though the iPhone 18 Pro Max has taken the top spot.
