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Saeed iPhone
Saeed iPhone

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Implementation of Battery Firmware Throttling for Shipping Compliance

Implementation of Battery Firmware Throttling for Shipping Compliance

Apple has introduced a firmware-level battery management feature, Prepare to Ship, specifically for the iPhone 18 Pro Max.

Technical Overview

Due to the device's battery capacity exceeding 20Wh, it falls under specific shipping safety regulations. The feature programmatically limits the maximum state of charge (SoC) to ensure the total energy remains below the 20Wh threshold during transit.

  • Mechanism: The system modifies the battery management firmware to enforce a discharge and charge-limit state.
  • User Access: Exposed via Settings > General > Transfer or Reset iPhone.
  • Status Reporting: The system state is reflected in the device firmware, transitioning to Ready to Ship once the discharge threshold is met.
  • Reversibility: The limit is removed upon device activation or via the manual undo option in the settings menu, which may include a 14-day lockout period depending on the user's selected intent.

منبع خبر: https://www.macrumors.com/2026/09/18/iphone-18-pro-max-shipping-restriction/

Top comments (2)

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evannn-dev profile image
evan •

how does Prepare to Ship balance throttling between temperature spikes and low‑capacity scenarios without risking premature performance loss, and is there a watchdog to recover if the sensor data is out of sync

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saeediphone profile image
Saeed iPhone •

Good question. I should clarify one point in my post: Prepare to Ship is a battery energy limit, not performance throttling. Apple says it discharges the battery below 20 Wh and, for repair, trade-in, or return shipments, caps charging at 80% for 14 days. Apple notes the phone may get warmer while discharging, but its support docs don’t describe temperature-spike throttling, sensor-sync handling, or a watchdog recovery mechanism—so I can’t confirm whether one exists. If the process doesn’t show “Ready to Ship,” Apple says to contact Apple or the shipping company before sending it. Apple’s support instructions 🍎