Battery longevity stands as a major factor for numerous buyers when selecting a new Android smartphone. Extended battery life implies a reduced need to recharge your device during the day, even with heavy use. Although the battery landscape has improved to some degree in recent years — primarily due to smartphones incorporating larger batteries and enhanced software optimization — some Android smartphone manufacturers consistently outperform their competitors regarding battery performance. CNET’s comprehensive testing highlights that the Chinese brand OnePlus excels particularly in battery performance, surpassing notable companies like Google and Samsung, which are among the most favored smartphone brands.
CNET states that the OnePlus 15 currently ranks as the Android phone with the best battery life available. However, it is not the sole OnePlus model to feature among the elite in battery longevity. The OnePlus 13R and OnePlus 15R also provide outstanding battery life, only falling short of the Poco F7 Pro in comparison to the OnePlus 15. Here’s a look at the reasons behind the excellent battery life of the OnePlus 15 and other models from the brand, alongside the elements that influence a phone’s battery efficiency.
The OnePlus 15 is equipped with an extensive battery
One of the primary reasons the OnePlus 15 offers lengthy battery life is the substantial size of its battery. It is fitted with an impressive 7,300mAh cell, enabling the phone to endure for extended periods. In our OnePlus 15 assessment, we observed that the device comfortably lasted for two days, alleviating concerns of it depleting within a single day. Other reviewers echo this sentiment regarding the battery performance of the phone, often recommending it among the top options for battery life. The OnePlus 15 also achieved high marks in similar evaluations conducted by Phone Arena, Tom’s Guide, and ZDNet, and placed second in a battery drain test led by YouTube creator Mrwhosetheboss. The sole device that surpassed the OnePlus in Mrwhosetheboss’s analysis was the Find X9 Pro from its sister brand Oppo, which boasts an even larger 7,500mAh battery.
If you’re curious about how OnePlus has managed to include such a large battery in the OnePlus 15, the key lies in silicon-carbon (Si-C) technology. In contrast to conventional Lithium-ion (Li-ion) batteries, Si-C batteries possess a higher energy density, allowing them to store more power within the same design space as a Li-ion battery-equipped phone. The OnePlus 15R and OnePlus 13R, which utilize the same battery technology, are fitted with 7,400mAh and 6,000mAh batteries, respectively. Even the Poco F7 Pro, which achieved superior battery life compared to the OnePlus 15R and 13R in CNET’s evaluation, although not officially available in North America, also adopts a 5,600mAh Si-C battery.
According to CNET’s findings, the only Android phones that deliver similarly remarkable battery life while using standard Li-ion batteries are the Motorola Edge (2025) and the Motorola Moto G Stylus (2025), featuring 5,200mAh and 5,000mAh batteries, respectively.
What factors influence a phone’s battery efficiency
At first glance, it might not be surprising that a phone with a 7,300mAh battery exhibits excellent battery life, yet multiple variables can affect your device’s endurance. Key factors include the display resolution, screen brightness, processor efficiency, and operating system optimizations. A higher display resolution often consumes more battery, as does increased display brightness; hence, many high-resolution phones feature built-in lower-resolution modes for use when optimum clarity isn’t essential. Furthermore, your device’s software will alert you that maintaining peak display brightness will deplete battery life.
Processor efficiency and OS-level optimizations are determined by the chip manufacturer and the phone brand, which is why CNET’s assessments, which also evaluated the battery life of various iPhone models, ranked the iPhone 17 Pro Max as the top performer among all phones and the iPhone 17 in second place, tying with the OnePlus 15, despite having smaller batteries. This advantage is attributed to the efficiency of both Apple’s chips and iOS. Even a processor that is not highly efficient but consumes little power due to its lower performance can enhance a phone’s battery life. This trend was also noted with the Moto G Stylus (2025) in CNET’s testing. It employs a mid-range Qualcomm Snapdragon 6 Gen 3 chip, compared to the flagship Snapdragon 8 Elite Gen 5 chip of the OnePlus 15. Thus, while a larger battery contributes to battery life, it does not always assure leading performance.