I have an Acer laptop (AS4820TG, it's about 2 years old), and I recently installed Windows 8 to a partition I made on my SSD (now I'm dual booting 7 and 8). My laptop's always had pretty good battery life.
On Windows 7, fully charged, windows sometimes estimates that I'll get 8.5 hours. Of course, that never happens, but nonetheless I can still squeeze a good 5-6 out of it if I'm saving power in as many ways as possible.
However, with Windows 8, on a full charge, I only get a prediction of perhaps 1.5-2 hours. It usually lasts not much more than one, even if I keep it in power saving mode and don't do anything intensive.
The one thing I know is hurting me is that with the fresh install, I lost the ability to automatically power off the optical drive. Other than that, I can't figure out what's slashing my hours! Even if it's unsolvable, can someone suggest what else might be the culprit? Thanks!