Apple's next-generation flagship smartphone, the iPhone 18 Pro Max, has surfaced in a new leak that points to a significant battery upgrade. While the company has yet to officially announce the device, fresh reports suggest it could feature the largest battery ever used in an iPhone.

The latest leak also claims that battery capacity may differ depending on the region, with eSIM-only models expected to include a larger battery than versions equipped with a physical SIM card slot.

iPhone 18 Pro Max Battery Capacity Leaked

According to information shared by Duoge Internet Technology on the Chinese social media platform Weibo, Apple may offer two battery configurations for the iPhone 18 Pro Max.

The reported battery capacities are:

• eSIM-only model: Up to 5,425mAh
• Physical nano-SIM model: Around 5,235mAh

The leak suggests that removing the physical SIM tray creates additional internal space, allowing Apple to install a larger battery in markets where eSIM is the only connectivity option.

However, Apple has not confirmed these details, so the specifications should be treated as unofficial.

Larger Than the Previous Generation

If the report proves accurate, the iPhone 18 Pro Max would offer a noticeable battery increase over the previous generation.

According to the leak, the iPhone 17 Pro Max reportedly featured:

• 5,088mAh battery in the eSIM-only version
• 4,823mAh battery in the physical SIM version

The new figures indicate Apple could continue using the extra internal space created by eliminating the SIM tray to improve battery capacity.

A20 Pro Bionic Chip May Improve Efficiency

The report also claims that the iPhone 18 Pro Max could be powered by Apple's upcoming A20 Pro Bionic processor.

The chipset is expected to be manufactured using an advanced 2nm process, which could deliver:

• Better power efficiency
• Improved overall performance
• Lower energy consumption
• Longer battery life during everyday use

A combination of a larger battery and a more efficient processor could result in noticeable improvements in battery endurance.

iPhone 18 Pro May Also Receive a Battery Upgrade

Separate leaks have also hinted at larger batteries for the standard iPhone 18 Pro.

The reported capacities include:

• Physical SIM version: Approximately 4,056mAh
• eSIM-only version: Approximately 4,288mAh

For comparison, previous reports suggested the iPhone 17 Pro featured batteries of around:

• 3,998mAh (physical SIM)
• 4,252mAh (eSIM)

While the increase appears modest, it could still contribute to improved battery performance alongside next-generation hardware.

Why eSIM Models May Have Bigger Batteries

The reported difference between the two variants is believed to be linked to internal design.

By removing the physical SIM tray, manufacturers gain extra internal space that can be used for:

• A larger battery
• Improved cooling systems
• Additional hardware components

Apple has already introduced eSIM-only iPhone models in select markets, making this design approach increasingly practical.

Official Details Still Awaited

Apple has not officially revealed the iPhone 18 series, and the leaked specifications remain unconfirmed. Final battery capacities, processor details, and hardware features may change before launch.