If I’m pitting the OnePlus 15 against the Galaxy S25 Ultra, five real-world advantages tip me over to OnePlus in terms of what you’re getting for your money: battery longevity and charging speed, newer silicon, actual gaming benefit, and several smaller everyday conveniences that mount up. The S25 Ultra is still king of camera versatility and ultra-long software support, but the OnePlus 15 is the phone I’d actually want to live with day in and day out.
A Bigger, Smarter Battery That Lasts Noticeably Longer
The OnePlus 15 boasts a larger 7,300mAh cell — vastly larger than the Galaxy S25 Ultra’s 5,000mAh battery. In side-by-side 4K HDR playback at matched Full HD resolution, for example, the OnePlus drained about 8% of its battery in an hour compared to 11% on the S25 Ultra — a short gap that would increase over the course of a day. In mixed use, I was guaranteed two days with the OnePlus; the Galaxy usually ran dry by evening of day two.
OnePlus accomplishes that through a silicon-carbon chemistry that improves energy density, making the phone lighter despite the larger capacity than Samsung’s flagship. That’s the kind of design trade-off that makes sense in practice: big battery life increases, minus the hand fatigue price.
Wired Charging That Reorganizes Your Day
It’s in the charging that the OnePlus 15 feels like a game-changer. And thanks to 120W wired charging (that’s 80W in the US), I’m habitually going from almost empty to full in less than an hour… Even when I don’t plug in until right before lacing my shoes, a five- to 10-minute sesh moves the needle in a meaningful way.
The Galaxy S25 Ultra is by no means so. When I watched charge curves, Samsung’s rate drops pretty quickly in the cycle — several times by 20–35% — extending total times well beyond an hour. The OnePlus also supports open standards such as USB Power Delivery and PPS (USB-IF protocols) in pursuit of higher charging rates — up to 36W and 55W, respectively — and faster proprietary wireless charging, while Samsung’s Qi2 support is the one you want for standard magnetic accessories (says the Wireless Power Consortium). For me, however, it’s fast wired top-ups that are the game changer which the S25 Ultra doesn’t offer.
Faster Storage for Smoother Performance on the Latest Silicon
The OnePlus 15 is one of the first phones globally to feature Qualcomm’s latest Snapdragon 8 Elite Gen 5 and upgraded Oryon V3 CPU cores along with a next-gen Adreno GPU. The S25 Ultra is powered by a custom “For Galaxy” version of the chip from last year. In real-world use, that generational jump manifests itself in everything from app launches to heavy multitasking.
In our own testing the OnePlus 15 posts both single- and multi-core Geekbench 6 scores (the creation of Primate Labs) that are higher than those of the S25 Ultra. The storage is snappier as well: We noticed measurably faster reads and writes from UFS 4.1 on the OnePlus than on Samsung’s implementation in our transfer tests. Those gains aren’t just existential and theoretical; they make the phone feel faster every time you install a big app, export a video, or pull down data-heavy files.
Gaming Benefits That Really Matter for Responsiveness
Where it counts to gamers, though, OnePlus has tuned the 15 for speed. The 165Hz display will push some competitive mainstays such as Call of Duty Mobile (seems apt) to a blistering 165fps, and I was consistently seeing frame rates north of the 160fps mark when the game would allow it. Many games are still locked to 60fps or 120fps, but when the support is in place, it’s a clear difference.
Equally important is touch response. OnePlus is quoting it with a 3,200Hz touch sampling rate, which stands way above the typical 240Hz figures on many mainstream flagships. That statement is impossible to prove without instrumentation that can measure finger taps in sub-millisecond amounts, but the subjective benefit certainly is real: lighter taps register, swipes feel more adhesive, and aim adjustments are tooled with precision.
It’s a question of QHD+ on the Galaxy or 1.5K (1272 x 2772) resolution on this panel, which is slightly less sharp. In hand, however, the clarity is excellent and streaming 4K content still looks very crisp; that slightly lower resolution probably helps keep battery life in such good shape. It’s a smart move for those who value frame rate and stamina above spec-sheet bragging rights.
Products Offering a Small Comfort That Make a Big Impact
It’s daily niceties that push the OnePlus 15 over the line for me. The ultrasonic in-display fingerprint reader is also extremely fast — tap, lift quickly and it’s already reading your prints — while the S25 Ultra works best with a longer press. It’s a little bit of friction that builds for hundreds of unlocks.
Durability gets a bump, too. The OnePlus 15 also includes IP69 and IP69K ratings for high-pressure, high-temperature water jets as defined under ISO 20653, providing peace of mind for your messiest mishaps. Throw in an IR blaster for controlling old TVs and AC units without the need to hunt for remotes, and a reprogrammable Plus Key that serves as a one-press shortcut to the camera, flashlight, translation, or OnePlus’s AI assistant — this is the kind of quality-of-life bonus functionality you start using on a daily basis.
To be clear, Samsung’s flagship has its own advantages: a more versatile set of cameras and a lengthier OS support horizon are important to some consumers. But if your priorities are the same as my favorite things in a phone — long battery life, genuinely fast charging, including gaming performance and daily conveniences — then the OnePlus 15 is that little bit more desirable.