iPhone 18 Pro Teardown: How Apple Improves Charging Speed and Cooling at What Cost?

A first look under the hood of the iPhone 18 Pro reveals: Cupertino has not only installed the A20 Pro, but has completely revamped the internal components – with clear compromises.

The new iPhone 18 Pro and its larger sibling, the iPhone 18 Pro Max, appear almost identical to their predecessors on the outside – even old protective cases fit the new casings without any problems. However, anyone who carefully lifts the display panel will find a fundamentally redesigned internal architecture. Apple had to completely reconfigure the internal space to manage heat from the A20 Pro chip while also making room for a smaller Dynamic Island. The result is an extremely densely packed design that poses significant challenges for independent repair shops.

Under-display technology reduces the size of the Dynamic Island.

The most noticeable change directly below the display concerns the redesigned Face ID sensor. Apple has moved this module far into the upper left corner of the device and, for the first time, is using an under-display solution for the infrared camera. The manufacturer places a special, lower-density pixel arrangement in front of the sensor, allowing invisible infrared light to pass through unimpeded. This trick lets Cupertino noticeably shrink the Dynamic Island's black cutout without compromising familiar unlocking security.

This optical refinement, however, comes at the cost of significantly increased display complexity. The intricate layering and precise alignment of the sensor area make it extremely difficult for third-party companies to manufacture replacement panels. Those hoping for inexpensive aftermarket replacements after drop damage will likely face noticeable compromises in fit and functionality. Furthermore, the disassembled front panel reveals redesigned cable routing and the extra space needed for the larger main camera. Anyone expecting a spacious interior in the iPhone 18 Pro, given the mechanical camera aperture, will see in the teardown just how densely packed the upper part of the casing actually is.

Giant vapor chamber and wider battery connector to combat the A20 heat

The main reason for the changed internal layout is the processor's thermal requirements. The A20 Pro, manufactured using the modern 2-nanometer process, now sits higher on the logic board. To prevent dangerous heat buildup under sustained full load, Apple has incorporated a significantly larger vapor chamber. This vapor chamber contacts the chip directly and is complemented by a new thermal pad material. Cupertino is clearly attempting to nip the dreaded throttling during computationally intensive tasks in the bud.

Underneath the battery, disassembly reveals another interesting detail: the battery connector is significantly wider than on the previous model. This reinforced connection suggests that Apple has increased the internal charging currents to enable noticeably faster charging speeds. However, the manufacturer remains characteristically stingy with battery capacity. The version shown in the teardown, with a physical SIM card slot, has a 4,056 mAh battery, which is slightly less than the eSIM model. Compared to the iPhone 17 Pro, this represents a meager increase of just 1.7 percent. Initial measurements and battery life tests show correspondingly negligible differences in real-world use.

Embedded chips make circuit board repairs almost impossible.

Cooling and power supply have been upgraded, but Apple is further tightening the screws on repairability. In the new Pro models, the NAND flash memory chips and the central power management ICs are embedded directly between the individual layers of the multi-layer circuit board. What engineers consider an extremely space-saving compaction is a disaster for independent repair shops. Replacing defective memory chips or soldering in new charge controllers without damaging the board layers has become virtually impossible, as micro-soldering between the layers is prevented.

The repair experts therefore rightly award the mainboard the greatest difficulty rating: five out of five stars for working on the mainboard. Anyone hoping for affordable chip-level repairs after the official launch of the iPhone 18 Pro in the event of expensive hardware defects will thus be largely out of luck. Only replacing the display and battery, each with two stars for effort, seems somewhat more accessible, while the rear camera module, with four stars, remains in the demanding range.

In the end, the disassembled flagship leaves a deeply ambivalent impression. On the one hand, the technical details, such as the cleverly miniaturized Dynamic Island and the elaborate cooling system for the A20 Pro, are impressive. On the other hand, Apple has locked internal components away from independent repair shops more ruthlessly than ever. As was already evident during the iPhone 18 Pro pre-sales, buyers are hardly deterred by such hurdles. However, users will ultimately pay the price for this extreme level of security when a technical defect occurs on the mainboard after the warranty expires.

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