Apple Uses 20Wh Firmware Lock on iPhone 18 Pro Max, Unlocking 21.75Wh After Setup
Updated
Updated · The Verge · Sep 21
Apple Uses 20Wh Firmware Lock on iPhone 18 Pro Max, Unlocking 21.75Wh After Setup
3 articles · Updated · The Verge · Sep 21
Summary
Apple built the iPhone 18 Pro Max with a software cap that keeps its single-cell battery under the 20Wh shipping threshold until the phone is first activated.
After setup, that firmware lock removes itself and restores the battery to its rated capacity—about 21.75Wh on U.S. eSIM models and 21.06Wh on European versions with a physical SIM slot.
For repairs or resale, Apple added a “Prepare to Ship” setting that reimposes the limit by capping charging at 80% for 14 days; the phone may need to discharge and can run warmer during the process.
The workaround offers Apple a way to ship a larger battery without moving to the dual-cell designs many Android makers use outside Asia to comply with the same rules.