iPhone 15 Pro Max Reaches 1,000 Charge Cycles With 81% Battery Health, Engadget Reports

Apple defines one charge cycle as using 100 percent of a battery's capacity, not necessarily in a single charge. A phone that drops from 100 percent to 50 percent and is charged back to 100 percent completes a cycle when it reaches 50 percent again, Engadget noted. Higher cycle counts mean more chemical aging.

Engadget's iPhone 15 Pro Max has a 4,422 mAh battery. When new, the device lasted nearly two days and reached more than 12 hours of screen-on time, the report said. It now often needs a charger before evening. The battery health reading of 81 percent has not yet triggered iOS's battery service warning, but the effects of wear are visible in daily use.

Apple introduced its Battery Health metric after the 2017 batterygate controversy, in which users said older iPhones slowed down as batteries aged. Apple said the performance management was designed to prevent unexpected shutdowns, and later added a toggle to disable it. The iPhone 15 series was the first to show battery cycle count alongside battery health.

Engadget said two iOS releases made the experience worse. iOS 18 brought complaints about performance, bugs and poor battery life; Apple Intelligence features heated the device and drained the battery faster. iOS 26 then spent a year slowing iPhones and hurting battery life, according to the report. iOS 27 focuses on performance and stability, with app launch times up to 30 percent faster, photos loading up to 70 percent quicker and AirDrop transfers up to 80 percent faster. Engadget said even the first developer beta was smoother than any stable iOS 26 release, and the iPhone 15 Pro Max now runs like an entirely different phone. It still requires at least two charges a day, and charging from 80 to 100 percent remains slow.

The hardware has held up well, Engadget said. The iPhone 15 Pro moved from stainless steel to titanium, making the phone lighter. Apple returned to a unibody aluminum chassis with the iPhone 17 Pro, citing better thermal performance, but Engadget said the newer Pro phones are easier to scratch and dent; there have been reports of new iPhone 18 Pro devices getting scratched within days of regular use. Engadget's iPhone 15 Pro Max body has no scratches despite mostly being used without a case. Its screen has minor scratches, but the titanium frame and glass back look nearly new. The triple-camera system still takes good photos and videos, the buttons remain clicky and the speakers are among the best Engadget has heard on a smartphone.

A separate Engadget report describes the warning signs that an iPhone battery needs replacement. Users can check Settings > Battery > Battery Health, where the overall state appears as Normal or Significantly Degraded. The latter comes with a disclaimer suggesting a battery replacement to restore full performance. On iPhone 15 and newer, the same screen shows total cycle count. iPhone 14 and earlier are designed to reach 80 percent capacity at 500 cycles; newer models are rated for 1,000 cycles.

Maximum battery capacity shows current capacity compared with when the battery was new. Once it drops below 80 percent, Apple considers the battery worn out and suggests replacement, Engadget reported. Other signs include needing a power bank to get through the day after checking for excessive app drain, rapid percentage drops, unexpected shutdowns even when the battery is above single digits, sluggish performance during gaming, large video exports or 4K streaming, and quick heating when the phone is unplugged or barely in use. A battery that bulges out of the case is a safety hazard; users should stop using the phone and contact Apple Support.

AppleCare can affect replacement costs. With an active subscription, Engadget said, there is no service fee for replacing a battery that has dropped below 80 percent. Outside an AppleCare plan, service prices range from $69 for a new iPhone 6s battery to $129 for an iPhone 18 Pro Max battery.