Three hours of YouTube: 30 percent gone on an iPhone 15 Pro Max, 29 on a 16, 27 on a 17, 25 on the iPhone 18 Pro Max. That's the shape of Matt Talks Tech's 48-hour test, which swaps benchmarks for the apps people actually run, every phone from 100 percent, background refresh off, the three older phones at 100 percent battery health and under 350 cycles.
The gaps grow with the app. Three hours of TikTok Reels on a loop cost 29, 25, 22, and 19 percent across the four phones; Instagram ran 28, 24, 21, 18. Maps with the screen on for the same three hours was the heaviest: 45 percent on the 15 Pro Max, 40, 34, and 30 on the 18. A Shortcuts routine that opened the camera every minute for 20 seconds and took a photo landed at 27, 24, 21, 18. The iMessage and WhatsApp readings, 20 to 13 percent, come from the Battery settings screen, and the channel keeps them apart from the drain tests since they measure differently.
So the 18 Pro Max wins every column, by roughly 10 points over the 15 Pro Max and 2 to 4 over the 17. The channel's verdict follows the size of the gap: 15 Pro Max owners have a real reason to move, especially heavy Maps users; 16 owners should weigh it against a battery replacement; 17 Pro Max owners shouldn't upgrade on battery alone. The channel credits nothing in particular; MKBHD's iPhone 18 Pro battery review credits the A20 Pro.
The useful number for iPhoners weighing the jump is Maps: 15 points between the oldest and newest phone over three hours of navigation. Everything else is a rounding error against a fresh battery in the phone you own.
