Lowering Power use on the Kogan Agora Laptop

I changed the graphical user interface on my Kogan Agora Laptop and increased the battery time by 45 minutes. This is still a relatively short 2 hours and 45 minutes (much less than the claimed 3.5 hours). So I tried some some power reduction advice. The suggested CPU Frequency Scaling applet did not work, reporting that the CPU frequency was fixed. However, I was able to install the "powertop" application. Here are the suggestions it made:

1. Disable the unused bluetooth interface with the following command: hciconfig hci0 down ; rmmod hci_usb
2. enable HD audio powersave mode by executing the following command:
   echo 1 > /sys/module/snd_hda_intel/parameters/power_save
   or by passing power_save=1 as module parameter
3. Suggestion: Enable USB autosuspend for non-input devices by pressing the U key
4. Suggestion: Enable wireless power saving mode by executing the following command:
   iwconfig wlan0 power timeout 500ms
5. Suggestion: Enable SATA ALPM link power management via:
   echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
   or press the S key.
6. Enable the CONFIG_INOTIFY kernel configuration option.
   

I tried all of these, except turning off Bluetooth, as I occasionally want to use a Bluetooth device and CONFIG_INOTIFY as apparently this is not needed for new versions of Linux. But even so, I found the Bluetooth light which was on the whole time previously is now off, unless I am actively using a Bluetooth device. The "enable HD audio powersave mode" appears this may only work under very limited conditions.

Powertop also reported:

1. The program 'firefox-bin' is writing to file 'ECRYPTFS_FNEK_ENCRYPTED.FXZX1as' on /dev/sda1.
   This prevents the disk from going to powersave mode.
2. The program 'rs:main Q:Reg' is writing to file 'syslog' on /dev/sda1.
   This prevents the disk from going to powersave mode.
3. The program 'upowerd' is writing to file 'history-rate-Kogan_Agora-38-SN0' on /d
   ev/sda1.
   This prevents the disk from going to powersave mode.
   

Top causes for wakeups:
33.2% (137.7) PS/2 keyboard/mouse/touchpad interrupt
31.9% (132.1) npviewer.bin
17.1% ( 70.9) [extra timer interrupt]
5.1% ( 21.1) firefox-bin

It was frustrating that these suggestions flashed on the screen for a few seconds and then disappeared.

However, there may be a fault in my Kogan's battery or charger, as after several hours the system reports it will still be another 50 minutes before the battery is fully charged.