Before you begin
Follow this guide to replace the battery on an iPhone 13 Pro Max. If your battery is swollen, take appropriate precautions. Note: On iOS 17.6 and earlier, your iPhone may display a warning about the “genuineness” of the battery after the repair, even when using original Apple parts. If your iPhone functions normally, you can safely ignore the warning. On iOS 18 and newer, authenticate your new battery using Apple's Repair Assistant. For optimal performance, after completing this guide, calibrate your newly installed battery: Charge it to 100% and keep charging it for at least two more hours. Then use your iPhone until it shuts off due to low battery. Finally, charge it uninterrupted to 100%.