iPhone 18 Pro Max reaches more than 18 hours of battery life, still nearly 7 hours less than OnePlus 15

(Dan Tri) - iPhone 18 Pro Max reached 18 hours and 27 minutes in Tom's Guide's battery life test. This result is nearly 7 hours lower than the leading model, OnePlus 15.

Battery life has long been one of the factors that users care about when choosing a high-end phone.

With iPhone 18 Pro and iPhone 18 Pro Max, Apple continues to improve this factor by combining larger battery capacity with the energy saving capabilities of the A20 Pro chip.

According to the latest review by Tom's Guide, the above changes have brought remarkable results.

iPhone had the best battery life in testing

To evaluate battery life, the tech site had the phones continuously surf the web over a cellular network with the screen set to 150 nits of brightness. The process is maintained until the device runs out of battery.

Using the same method means results between phones can be used as a relative reference.

The battery life test is by letting the devices continuously surf the web over the mobile network, with the screen brightness set at 150 nits (Photo: Tom's Guide).

iPhone 18 Pro Max averaged 18 hours and 27 minutes. Meanwhile, the previous iPhone 17 Pro Max reached 17 hours and 54 minutes in the same test. Thus, the new generation extends operating time by more than 30 minutes.

The improvement on iPhone 18 Pro is even more pronounced. The device averaged 16 hours and 17 minutes, an increase of nearly an hour compared to the iPhone 17 Pro's 15 hours and 21 minutes.

This result shows that both Pro versions this year have improved usage time, in which Pro Max continues to be an outstanding choice if users prioritize battery.

In the test, the iPhone 18 Pro Max also scored higher than some current Android flagships, including the Galaxy S26 Ultra. However, the distance between devices also depends on the screen mode and specific testing conditions.

iPhone 18 Pro Max achieved 18 hours and 27 minutes in the battery life test, the highest among the iPhone models compared (Graphic: Doan Thuy).

According to Apple, the iPhone 18 Pro Max can play video for up to 45 hours, up from 39 hours for the iPhone 17 Pro Max. iPhone 18 Pro reaches a maximum of 36 hours, compared to 33 hours on the previous generation.

However, the numbers Apple announced cannot be directly compared with the results of this technology site.

Apple measured video playback time under native conditions, while the review team simulated continuous web surfing over a cellular network. Therefore, the two results reflect different usage scenarios.

Still far behind in the leading position

Despite being the iPhone with the best battery life in the test, the iPhone 18 Pro Max still has a significant gap with the leading device.

The OnePlus 15 lasted up to 25 hours and 13 minutes in the same test.

Compared to the average of 18 hours and 27 minutes of the iPhone 18 Pro Max, the gap between the two devices is up to 6 hours and 46 minutes.

Besides usage time, another notable change on this year's iPhone 18 Pro and iPhone 18 Pro Max is charging speed.

The two devices support 60W wired charging, significantly improved compared to the previous generation.

In testing, the iPhone 18 Pro reached 53% battery after 15 minutes and 80% after 30 minutes. With iPhone 18 Pro Max, the device reached 44% after 15 minutes and 77% after half an hour. The slower percentage increase than the Pro version may be related to the larger battery capacity.

iPhone 18 Pro reaches 53% battery after 15 minutes of charging, while iPhone 18 Pro Max reaches 44% with a 60W charger (Graphic: Doan Thuy).

Thus, instead of just extending usage time, Apple is also shortening the time users have to wait to recharge the device.

Test results show that iPhone 18 Pro Max has made progress in battery compared to the previous generation and became the iPhone with the highest battery life in the test.

However, the gap of nearly 7 hours with the leading device also shows that the room for improvement is still large.

Test numbers do not mean that actual users will achieve the exact above duration. Usage time also depends on screen brightness, connection quality, applications and usage habits.

However, in the same testing method, the result of 18 hours and 27 minutes still shows that the battery is one of the notable upgrades on the iPhone 18 Pro Max.