Apple does not announce or list the battery capacities in mAh for iPhones, and the iPhone 18 Pro Max follows the same pattern. The spec sheet gives hours of use and video playback and says nothing about the size of the cell inside.
Apple rates the iPhone 18 Pro Max at up to 30 hours of typical use and 45 hours of video playback. The company credits the longer runtime to more battery capacity and greater efficiency, but never says how much capacity. Apple has not given a public reason for leaving the number out.
Apple’s Only mAh Figure Comes From an EU Regulation
The one place a capacity number appears is the EU, where a product information sheet under Regulation (EU) 2023/1669 has to list rated battery capacity in mAh. That is how Apple’s EU energy labels put the physical-SIM iPhone 18 Pro Max at 5,391 mAh, up from 4,823 mAh on the iPhone 17 Pro Max.
The US iPhone 18 Pro Max has no SIM tray, which gives Apple room for a larger cell, and Apple’s US page rates that version higher still. Neither the US nor the UK spec page prints a capacity.
Hours Make the iPhone 18 Pro Max Look Better Than mAh Does
The OnePlus 15 lists a 7,300 mAh silicon-carbon battery and up to 31 hours of video playback on its US product page. The physical-SIM iPhone 18 Pro Max has a cell about 26 percent smaller and a rating of 43 hours on Apple’s UK specs. The OnePlus 15 has the bigger battery, and the iPhone 18 Pro Max has the higher video rating by about 39 percent.
- iPhone 17 Pro Max (physical SIM): 4,823 mAh, up to 37 hours of video playback
- iPhone 18 Pro Max (physical SIM): 5,391 mAh, up to 43 hours of video playback
- OnePlus 15 (US): 7,300 mAh, up to 31 hours of video playback
Apple’s own generational change shows the same gap between the two numbers. From the iPhone 17 Pro Max to the iPhone 18 Pro Max, capacity rose about 12 percent on the physical-SIM models, and rated video hours rose about 16 percent.
A capacity in mAh also leaves out cell voltage, so it does not give stored energy on its own. Apple’s hours come from defined tests instead. The video figure loops a 2 hour 23 minute HDR movie with Bluetooth paired to headphones and Auto-Brightness and True Tone switched off, and typical use reflects median iPhone usage across messaging, photos, music, social media, streaming, games, browsing and navigation. The spec page lists Apple’s own A20 Pro chip, N1 wireless chip and iOS 27 beside those ratings.
Silicon-carbon cells do fit more capacity into the same space, and OnePlus says the 15 percent silicon content in its battery holds 80 percent of capacity after four years. Apple’s US iPhone page lists the iPhone 18 Pro Max at up to 45 hours of video playback, six hours more than the iPhone 17 Pro Max.
Our Take
Apple has never said why it skips mAh, so this is just my read. It builds the chip, the wireless chip and iOS 27 and tunes them against the battery, which allows it to provide a lot more hours per mAh. A cell size invites a comparison with phones carrying 7,000 mAh, and Apple would lose that one on paper. When a reviewer points to mAh totals or silicon-carbon cells, always treat it as half a comparison. It’s wiser to rely on rated and tested hours instead.
