My upgrade experience

[MurphCID]

Ok, HP claims that the Spectre x360 13.3" gets 8-10 hours of battery life under normal use with Windows. In practice, I have my monitor at 50% brightness, running Mint 19.0, and I get anywhere between 2.5 and 4 hours doing just web surfing, some YouTube watching, and maybe a little LibreOffice. Is there something that I am missing? I have gone into battery settings, and there is not much I can do it seems. I'd like to get 6+ hours if possible, I know that Linux will never be as energy efficient as MS/Apple since they have control of the manufacturers and the power settings, but 6 hours would be nice. The laptop is relatively new (last December), and I let it discharge to 15% or less before I connect power to recharge (most of the time I let it get to 8-9%).