Dark Mode May Not Save Smartphone Battery, BBC Study Finds

Switching to dark mode on smartphones may not extend battery life as widely believed, according to a new study by the BBC’s Research & Development team. The research found that most users increase their screen brightness when using dark mode, canceling out any potential energy savings.

The study revealed that 80% of participants who switched to a dark background then adjusted their phone’s brightness upwards, resulting in faster battery drain. In contrast, those using standard light mode were less likely to adjust screen settings, maintaining lower brightness levels and preserving battery life.

This real-world behavior contradicts previous lab-based studies that showed dark mode could significantly reduce power consumption. For example, a 2021 Purdue University study found that dark mode could cut energy use by 42% at full brightness. Similarly, Google engineers reported up to 63% power savings on OLED screens using dark mode. However, those tests did not account for users increasing brightness levels in daily use.

Zak Datson, an engineer with the BBC’s Research & Development team, emphasized the importance of considering real-world habits when evaluating energy-saving tips. “Some of the most common recommendations are overly simplistic,” he explained. “In the case of dark mode, some people end up using more energy.”

The study concluded that the most reliable way to conserve smartphone battery life is to reduce screen brightness. Lowering brightness can cut energy consumption in half compared to using a phone at maximum settings.

The research is part of the BBC’s broader sustainability campaign, which aims to reduce the corporation’s carbon emissions by 90% by 2050. The campaign also highlights the environmental impact of electronic devices, such as televisions and smartphones, while noting that travel is the largest carbon emitter in film production.

Ultimately, the study suggests that while dark mode might still offer energy savings for users who maintain lower brightness settings, simply dimming the screen remains the most effective way to maximize battery life.