The iPhone 18 Pro Max has a battery capacity over 20 watt-hours, which means there are additional shipping requirements. If an ‌iPhone 18 Pro‌ Max needs to be shipped somewhere, its maximum battery capacity has to be limited through firmware.According to Apple, the ‌iPhone 18 Pro‌ Max uses an "innovative battery-firmware solution" that limits battery capacity to below 20Wh between when the iPhone is manufactured and its delivery to a customer. Activating the iPhone removes the limit to make the battery's full charging capacity available. iPhones that are not yet activated or still in the box will not need Prepare to Ship because they are already limited to under 20Wh.Customers who need to ship the ‌iPhone 18 Pro‌ Max for repair, trade-in, or other purposes have to use a new Prepare to Ship feature. Prepare to Ship discharges the battery to below 20Wh and sets a charge limit so the iPhone stays below the threshold during the shipping process.The Prepare to Ship option can be accessed by going to Settings > General > Transfer or Reset iPhone > Prepare to Ship. Apple warns that the iPhone can become "warmer than usual" during Prepare to Ship if the battery needs to be discharged. When finished, the iPhone shows a "Ready to Ship" status in Settings.If Prepare to Ship needs to be undone, there is an option in the same section of the Settings app to undo the shipping preparation. Depending on the reason the user selected for the Prepare to Ship feature, there could be a 14-day waiting period before it can be disabled.Apple emphasizes that the ‌iPhone 18 Pro‌ Max is safe for shipping and air travel, and the limit has been added to meet shipping requirements. Since no other iPhones have a single-cell battery over 20Wh, this procedure isn't needed for other models.Related Roundup: iPhone 18 ProBuyer's Guide: iPhone 18 Pro (Buy Now)Related Forum: iPhoneThis article, "iPhone 18 Pro Max Requires 'Prepare to Ship' Battery Drain Before Shipping" first appeared on MacRumors.comDiscuss this article in our forums