Getting great battery life is very simple with a few tools:

• PowerTop - Intel tool for analyzing power-related settings for Intel chips.
• TLP Linux Advanced Power Management - Service that manages power settings.

PowerTOP can manage power settings too, but TLP offers greater configuration options. There are also some concerns about some of the settings PowerTOP likes to enforce.

Using this configuration, I'm able to get 10+ hours of light usage on a single charge.

Installation

Install the powertop & tlp packages:

pacman -S powertop tlp

Turn off S/PDIF light when sound not in use

TLP applies different settings when power is connected. Enabling SOUND_POWER_SAVE_ON_AC in the TLP configuration will suppress the S/PDIF light when on AC power.

SOUND_POWER_SAVE_ON_AC=1

Enable TLP Service

systemctl enable tlp
systemctl enable tlp-sleep
tlp start

Checking Settings with Powertop

Make sure you are running on battery power. Run PowerTOP and go to the Idle stats tab. You should see columns for Package & Core:

          Package   |             Core    |
                    |                     |
C2 (pc2)   43.8%    |                     |
C3 (pc3)    0.8%    | C3 (cc3)    1.8%    |
C6 (pc6)   26.6%    | C6 (cc6)    0.7%    |
C7 (pc7)    0.0%    | C7 (cc7)   81.8%    |
C8 (pc8)    0.0%    |                     |
C9 (pc9)    0.0%    |                     |
C10 (pc10)  0.0%    |                     |

The Core column will contain stats for each core and the GPU. The Package column is the most important, as it indicates the highest C-State that was reached. With TLP running, you should be able to reach at least C6.

I'm sure it's possible to reduce power usage even more. I'll keep this entry updated as I explore this area further.