I tested fast chargers with the best iPhone, Samsung, and OnePlus phones - and two surprised me
Original reporting by ZDNet
Smartphone manufacturers frequently tout impressive fast-charging speeds, with figures ranging from 25W to a staggering 120W becoming common marketing fodder. For many users, this promise of a rapid power-up is a key differentiator. But how often do our devices truly hit these peak numbers, and for how long? The reality, as an extensive test revealed, is often far from the advertised promise. To demystify these claims, we put three flagship smartphones – the Samsung Galaxy S26 Ultra, the iPhone 17 Pro Max, and the OnePlus 15 – through a rigorous charging evaluation, employing both their proprietary chargers and leading third-party alternatives. The aim was to uncover the true charging experience behind the marketing hype.
Unveiling the truth
Our findings uncovered significant discrepancies and unexpected outcomes. While the Samsung Galaxy S26 Ultra and iPhone 17 Pro Max surprisingly *exceeded* their rated 60W and 40W speeds, respectively, at certain points, the OnePlus 15 proved to be the biggest disappointment. Despite boasting an advertised 120W, it consistently charged at less than half that, maxing out at just 46W even with its own charger. Interestingly, third-party accessories often outperformed the manufacturers' own, with Samsung reaching a full charge in under an hour. This investigation underscores a crucial truth: the high wattage numbers promoted by brands are frequently misleading, suggesting that, for most users, peak charging speeds are largely overrated and the real-world experience can be a considerable departure from expectations.
Ultimately, our tests reveal a stark reality: advertised peak charging speeds are largely an overstatement of typical performance. While some devices, like the Samsung Galaxy S26 Ultra and iPhone 17 Pro Max, exceeded their stated maximums briefly, the majority of their charging cycles operated at a fraction of these figures. The most striking finding, however, was the consistent underperformance of the OnePlus 15, which never approached its advertised 120W, lingering instead in a significantly lower range. This data underscores that a phone's claimed wattage often serves more as a marketing talking point than a reliable indicator of real-world charging efficiency. Moreover, the superior performance of third-party chargers in some instances challenges the notion that proprietary accessories are always best.
Implications for Consumers
This disparity between promise and reality carries significant implications. For consumers, it fosters a landscape of potential misinformation, making informed purchasing decisions difficult. Manufacturers' focus on peak wattage, often achieved only under ideal and brief conditions, obscures the more crucial metric of sustained charging speed and overall time to full charge. This trend encourages a cycle where brands compete on numbers that don't fully translate to user experience, potentially leading to unnecessary upgrades or purchases of high-wattage chargers that offer diminishing returns.
Looking ahead, this ongoing disconnect could erode consumer trust and push for greater transparency from device makers. The industry may need to shift its emphasis from fleeting peak numbers to more honest representations of average charging rates and their impact on battery longevity. Users, in turn, should prioritize comprehensive reviews and practical tests over headline specifications, seeking devices that deliver consistent, efficient charging that aligns with their actual usage patterns, rather than chasing a theoretical maximum rarely experienced.
Frequently asked questions
- Are smartphone manufacturers' advertised fast-charging speeds truly representative of real-world performance?
- No, advertised peak charging speeds often do not reflect real-world performance. While some devices might briefly exceed their stated maximums, most of their charging cycle operates at a fraction of these figures. High wattage numbers are frequently marketing points, and the actual time to a full charge can differ significantly from expectations. Consumers should prioritize sustained charging speed over theoretical maximums.
- Do all smartphones consistently achieve their advertised peak charging wattages during daily use?
- No, many smartphones do not consistently achieve their advertised peak charging wattages. Tests reveal significant discrepancies, with some devices consistently charging at less than half their claimed speed. Even phones that briefly exceed stated maximums typically operate at lower wattages for the majority of their charging cycle. Peak numbers are often achieved only under ideal, brief conditions.
- Can third-party chargers sometimes outperform proprietary ones for smartphone fast charging?
- Yes, in some instances, third-party chargers can outperform manufacturers' proprietary accessories for smartphone fast charging. Testing has shown that certain third-party options can achieve a full charge faster or deliver more consistent power than the chargers included with the device. This challenges the common assumption that proprietary chargers are always the superior choice for optimal charging efficiency.