iPhone 18 Pro Max vs Galaxy S26 Ultra Battery Life

The iPhone 18 Pro Max lasts longer than the Galaxy S26 Ultra on a charge in both head-to-head reviewer tests we found, by roughly two to three hours depending on the test. The Galaxy S26 Ultra charges a little faster on a cable, so it suits people who top up often more than people who want to get through a long day without a charger.

{toc}

Specs that matter for battery life

Apple does not publish battery capacity in mAh. It gives hours of use instead, so the iPhone column below uses Apple's own claims plus the capacity figure reported by reviewers.

Spec	iPhone 18 Pro Max	Galaxy S26 Ultra
Battery capacity	Not published by Apple	5,000 mAh
Capacity reported by reviewers	5,391 mAh, or 5,567 mAh (eSIM-only)	5,000 mAh
Chip	A20 Pro	Snapdragon 8 Elite Gen 5
Display	6.9-inch OLED, up to 120Hz	6.9-inch AMOLED, 120Hz
Wired charging	50% in about 15 min (60W-capable adapter)	Up to 60W
Wireless charging	MagSafe and Qi2, up to 25W	Up to 25W

The iPhone figures come from Apple's iPhone 18 Pro tech specs page, which rates the Pro Max at up to 30 hours of typical use, 45 hours of video playback and 40 hours of streamed video. The 5,391 mAh capacity is not an Apple number. GSMArena lists it, and TechRadar gives 5,391 mAh for physical-SIM models and 5,567 mAh for eSIM-only models. Treat both figures as unofficial. Apple's launch announcement says eSIM-only models, which are sold in the US, have a larger battery than physical-SIM versions, and gives the 45-hour video figure for eSIM-only Pro Max models.

For the Galaxy, Tom's Guide's launch coverage and GSMArena's spec page agree on a 5,000 mAh battery, 60W wired charging (Samsung calls it Super Fast Charging 3.0) and 25W wireless charging. The US model runs the Snapdragon 8 Elite Gen 5.

Screen-on battery tests: what reviewers found

Two outlets have published head-to-head numbers. Their tests work differently, so read each result on its own and do not compare a Tom's Guide hour with a GSMArena hour.

Tom's Guide battery test

In its iPhone 18 Pro Max battery test, Tom's Guide sets each screen to 150 nits and runs a script that loads websites over a cellular connection until the phone shuts down. It measures overall endurance in one long, steady browsing session.

GSMArena Active Use Score

GSMArena's Active Use Score combines separate on-screen tests (web browsing, video streaming and gaming) into one figure in hours. In its iPhone 18 Pro Max vs Galaxy S26 Ultra comparison, the iPhone did better in every one of those on-screen tests.

Test	iPhone 18 Pro Max	Galaxy S26 Ultra
Tom's Guide web browsing	18h 27m	16h 40m
GSMArena Active Use Score	19h 20m	16h 22m

Tom's Guide puts the gap at 1 hour 47 minutes. On GSMArena's score it is close to three hours. Both tests put the iPhone ahead, so if all-day endurance is your main concern, it has the edge.

For context, Tom's Guide measured the smaller iPhone 18 Pro at 16 hours 17 minutes in the same browsing test, 23 minutes behind the Galaxy S26 Ultra. If you are weighing the 6.3-inch iPhone instead of the Pro Max, the two are close.

Charging speed: where the Galaxy wins

Apple does not state a wattage for the iPhone 18 Pro Max. Its spec page promises up to 50% in around 15 minutes with a 60W-capable USB-C adapter that supports Adjustable Voltage Supply (AVS), and up to 50% in 30 minutes on a MagSafe charger paired with a 35W or higher adapter. Both chargers are sold separately.

GSMArena measured both phones from empty on a wired charger:

GSMArena wired test	iPhone 18 Pro Max	Galaxy S26 Ultra
After 15 minutes	50%	51%
After 30 minutes	81%	84%
Full charge	55 minutes	43 minutes

The first half hour is nearly a tie. The difference shows at the end, where the Galaxy reaches 100% 12 minutes sooner. Tom's Guide got a different 30-minute result in its own testing (80% for the iPhone, 77% for the Galaxy), which is a reminder that charger, cable and starting temperature all move these numbers by a few points. In daily use, both phones go from low to most of a day's charge in about half an hour.

You only get these speeds with the right charger. The iPhone needs a USB PD 3.1 adapter with AVS and a 60W-capable cable, according to Apple's footnotes. The Galaxy needs a charger that supports Samsung's 60W Super Fast Charging 3.0.

Wireless charging and accessories

Both phones top out at 25W wireless. The iPhone has MagSafe built in, and Apple lists Qi2 support at up to 25W, so magnetic chargers, stands and battery packs snap on without a case. GSMArena lists the Galaxy S26 Ultra's 25W wireless charging as Qi2.2, and also lists 4.5W reverse wireless charging, so the Galaxy can top up earbuds or a watch from its own battery. If you rely on magnetic accessories, check that the specific charger or case you plan to buy is listed as compatible with the S26 Ultra.

Everything else in brief

Price (US, before tax): Apple's US store lists the iPhone 18 Pro Max 256GB unlocked at $1,299 (checked October 31, 2026). The Galaxy S26 Ultra launched at $1,299.99, according to Samsung's launch announcement, and Samsung.com showed the 256GB unlocked model at $1,149.99 on October 31, 2026. Samsung prices change often.
Software support: Samsung says the Galaxy S26 series gets seven years of security updates, and GSMArena lists the Galaxy S26 Ultra with up to 7 major OS updates. Apple does not publish an end date for iPhone software support.
Storage: the iPhone comes in 256GB, 512GB, 1TB and 2TB. The Galaxy comes in 256GB, 512GB and 1TB.
Chargers: neither phone's fastest wired speed works with an old 20W or 25W brick. You need a compatible adapter to see the times quoted above.

Verdict: which should you buy?

Choose the iPhone 18 Pro Max if you want the phone most likely to reach bedtime on a heavy day without a top-up. It won both reviewer endurance tests we found (by about two hours at Tom's Guide and about three at GSMArena), and its MagSafe support makes wireless charging accessories simple.

Choose the Galaxy S26 Ultra if you charge in short bursts during the day, or you would rather save money. It reached 100% about 12 minutes sooner in GSMArena's test, and its current Samsung.com price is lower than the iPhone's. It still delivered more than 16 hours in both tests, which covers most people's days.

If you are already settled on Android or iOS for other reasons, battery life alone is not a reason to switch. Both are among the longer-lasting large phones of 2026. If you are also looking at Google's flagship, see our iPhone 18 Pro vs Pixel 11 Pro battery comparison.

FAQ

Does the iPhone 18 Pro Max have a bigger battery than the Galaxy S26 Ultra?

Probably, but Apple does not say. GSMArena lists 5,391 mAh for the iPhone 18 Pro Max, and TechRadar lists 5,567 mAh for eSIM-only models. The Galaxy S26 Ultra is 5,000 mAh. None of the iPhone figures comes from Apple.

Which charges faster, iPhone 18 Pro Max or Galaxy S26 Ultra?

The Galaxy, by a small margin. In GSMArena's wired test it reached full in 43 minutes against 55 for the iPhone. After 15 minutes the two were within one percentage point.

Is the Galaxy S26 Ultra battery good enough for a full day?

For most people, yes. It ran 16 hours 40 minutes in Tom's Guide's web browsing test and scored 16 hours 22 minutes in GSMArena's Active Use Score. If you own one and hit a software problem after updating, our Galaxy S26 One UI 9 XML error fix may help.