If you want to maximize battery life on a Mac, you need to do Mac-specific things. The most energy efficient way to do things is to hook into proprietary APIs such as CTS and GCD. You can’t get around these by doing it yourself because they’re designed to coordinate tasks across all running processes.

This high level of coordination improves efficiency because the CPU can wake up, crank through the queue of scheduled tasks, and go back to sleep. If every process does it DIY, then the CPU just gets woken up repeatedly and your battery dies a death by a thousand cuts.