Try using tlp and powertop to diagnose the issue (your CPU might not be entering low power C states -- a common problem with older kernels that don't support th

Try using tlp and powertop to diagnose the issue (your CPU might not be entering low power C states -- a common problem with older kernels that don't support the latest Intel CPU architectures), so also upgrade your kernel. Linux has consistently gotten 1.5x as much runtime on battery for me as Windows.