Battery life is an increasing concern for mobile devices. Recent studies have provided initial evidence that applying performance tips is an effective mechanism for decreasing energy usage. However, the generalizability of such studies to real applications is unclear. We aim to provide deeper insights into whether mobile application developers can effectively reduce the energy consumption of their applications by applying performance tips.We conducted an empirical study to investigate the energy impacts of applying four commonly suggested performance tips to eight real Android applications. Considered performance tips are unlikely to impact energy usage in a statistically significant manner and, even when the impacts are statistically significant, the change in battery life is around 1%. Mobile application developers cannot expect to improve the energy usage of their applications as a by product of performance improvements. Tools and techniques that specifically target energy usage are necessary for significant improvements.