New leaks suggest Apple is preparing a significant battery upgrade for the iPhone 18 Pro Max, potentially giving the company's next flagship its largest battery ever. The trade-off, however, could be a device that is slightly thicker and heavier than its predecessor.

For years, Apple has prioritized balancing performance, industrial design and battery life rather than competing solely on battery capacity. The latest rumors indicate that strategy may be shifting as increasingly demanding on-device AI features require more power.

Larger battery could deliver nearly 10% longer battery life

Earlier reports suggested the iPhone 18 Pro Max would offer only modest improvements in battery endurance over the iPhone 17 Pro Max.

More recent leaks paint a different picture, indicating the new model could deliver nearly 10% longer battery life.

Well-known leaker Ice Universe now claims the iPhone 18 Pro Max will feature a 5,500mAh battery.

If accurate, that would represent a substantial increase over the 5,088mAh battery widely rumored for the iPhone 17 Pro Max.

An increase of more than 400mAh could noticeably improve real-world performance during demanding activities such as high-resolution video recording, gaming, photo editing and extended use of Apple Intelligence features.

It would also make the battery the largest ever installed in an iPhone, reflecting Apple's growing emphasis on endurance as smartphone workloads become increasingly power-intensive.

Thicker and heavier design

Ice Universe also reported that the iPhone 18 Pro Max could weigh around 240 grams, compared with an estimated 233 grams for the iPhone 17 Pro Max.

Although the difference is only 7 grams, some users may notice the added weight during prolonged use.

The phone's thickness is also rumored to increase from approximately 8.75mm to around 9mm.

While the increase of 0.25mm appears minor, it suggests Apple may be willing to compromise slightly on its ultra-thin design philosophy to accommodate a larger battery.

This is not the first report indicating that the iPhone 18 Pro Max may become thicker.

The latest leak, however, specifically attributes the change to the larger battery rather than other hardware components.

Camera rumors remain unclear

Another well-known source, Fixed Focus Digital, previously claimed that the iPhone 18 Pro Max would also grow in size but offered a different explanation.

According to that report, the increase would primarily result from a larger rear camera module rather than battery capacity.

The account even suggested the camera bump could become roughly 2mm thicker, although it remains unclear whether that figure refers only to the camera housing or the overall device thickness.

As a result, the two sets of leaks are not entirely consistent and will require further confirmation closer to the device's official launch.

Battery life likely to remain Apple's focus

Industry observers also note that neither Ice Universe nor Fixed Focus Digital has a perfect track record regarding Apple products.

Although Ice Universe has accurately predicted numerous Android smartphones, the source's history with iPhone leaks has been more mixed. Fixed Focus Digital has also produced reports with varying levels of accuracy.

For now, all information regarding the iPhone 18 Pro Max's dimensions, weight and battery capacity remains speculative.

Apple is expected to reveal the final specifications only when the device is officially introduced.

Even if the iPhone 18 Pro Max does become thicker and heavier, Apple is unlikely to highlight those physical changes during its product presentation.

Instead, the company traditionally emphasizes real-world battery life, such as additional hours of video playback, streaming or audio listening, rather than disclosing battery capacity in milliamp-hours.

If the current rumors prove accurate, the iPhone 18 Pro Max could deliver one of the most significant improvements in battery endurance seen on an iPhone in recent years.

The compromise would be a slightly bulkier device - an exchange many users may consider worthwhile if it means substantially longer use between charges.

Hai Phong