Mavericks was a big one for extending battery life. It came quite a bit after Snow LeopRd and introduced timer coalescing which significantly improved battery l

Mavericks was a big one for extending battery life. It came quite a bit after Snow LeopRd and introduced timer coalescing which significantly improved battery life across the board for all MacBooks: https://m.imore.com/mavericks-preview-timer-coalescing https://m.imore.com/mavericks-preview-timer-coalescing