How long-term use may affect real-world battery endurance

The OnePlus 15 launched with a large 7300 mAh silicon-carbon battery, one of the biggest capacities offered in a mainstream flagship phone. Its early results show excellent stamina in daily UK use, with strong endurance during streaming, navigation and high-refresh tasks. As with any smartphone, battery health decreases over time, so understanding how performance may look after six months is important for long-term buyers.

In its first weeks the OnePlus 15 delivers impressive screen-on-time thanks to the efficiency of its chipset and the stability of its battery chemistry. Many users comfortably achieve a full day of heavy use, and lighter days can stretch into a second. This strong starting point forms the basis for predicting how much endurance will remain after months of regular charging and daily wear.

Battery degradation is normal and expected in all lithium-based cells. Silicon-carbon batteries, however, are engineered to maintain health for longer, and OnePlus states that the technology is designed to retain over 80 percent capacity after four years of use. Six months represents only a small portion of this lifespan, meaning battery health loss during that period should be minimal for most users.

Based on typical usage patterns, a realistic projection for screen-on-time after six months suggests only a slight reduction. Under light to moderate tasks such as browsing, messaging, email, social media and streaming, the OnePlus 15 should still achieve around seven to eight hours of screen-on-time. This remains well within full-day performance, especially when combined with the phone’s efficient standby behaviour.

For heavier routines involving long gaming sessions, high-refresh-rate use, camera-intensive days or navigation, screen-on-time may settle around five to six hours after six months. This is a modest drop compared to early usage figures and aligns with what is expected from a battery of this size and design. Heavy users should still find the phone reliable enough to complete demanding days without mid-day charging.

Environmental conditions also influence long-term endurance. The UK’s colder months can slightly reduce performance when the phone is used outdoors for extended periods, especially during navigation or filming. However, silicon-carbon cells generally handle temperature variations better than traditional lithium-ion batteries, helping maintain more stable screen-on-time even as the device ages.

Charging habits play a meaningful role in how much battery health is lost over time. Avoiding prolonged time at 100 percent, limiting extremely high temperatures and using adaptive charging features can significantly slow degradation. The OnePlus 15 includes built-in battery optimisation settings that regulate charging behaviour overnight and reduce stress on the cell during daily top-ups.

Fast charging remains a major advantage even after six months of ownership. The phone can replenish a large amount of power in a short time, making it easier to compensate for any natural reduction in screen-on-time. Even if heavy use results in a lower end-of-day percentage later in the device’s life, quick charging ensures users are rarely inconvenienced.

Users who rely on 165 Hz refresh rate or extended gaming sessions may see a slightly faster decrease in daily endurance, but this is consistent with all high-performance smartphones. Switching to adaptive refresh rate or managing performance modes during long tasks can keep battery drain under control without noticeably affecting the user experience.

Overall, the OnePlus 15 is expected to maintain strong screen-on-time after six months, with only a minor, natural reduction from its launch performance. Most users in the UK can anticipate a reliable full day of use and, under lighter workloads, the potential for multi-day endurance. The design of the battery and the software optimisations ensure the device continues to feel dependable over time.

In summary, the OnePlus 15’s projected durability remains a key strength. With a large battery, efficient hardware and smart charging management, the device should deliver robust screen-on-time even after months of regular, real-world usage. For buyers seeking long-term stability without rapid decline, the phone offers a reassuring level of endurance.