Ideas for battery hypermiling methods?

[Zm1TDkSnQkY4KEqskCARSBpk]

Today, I forgot my power supply for my laptop, so I decided to try to make the battery last as long as I could before I borrow someone else's power supply. This is what I did:

• Kept my screen brightness to minimum
• Terminated all "active" background processes (updates, backups, email pulling, etc.)
• Avoided all media playback
• Disabled the wi-fi (using the switch on the side) whenever it wasn't being actively used, but switched it back on a few seconds before I would need it to give it time to connect
• Put the laptop to sleep whenever it wouldn't be actively used for more than a minute, and tried to avoid using it as much as I could
• Staggered CPU intensive activities (such as webpage loading) so the CPU load stayed low
• Watched the system temperatures and coordinated all input to avoid too many CPU spikes and make sure the fan never came on

With these efforts, I was able to get my power consumption as reported from the battery down from about 45 watts (about what it is during my normal use) to about 25 watts, but I was still only able to get the battery to last me about 2½ hours (total, not actual use), though a teacher forcing me to raise my brightness for an online test that lasted about 20 minutes probably didn't help. This leaves me with a few questions for how I can improve the performance the next time it happens:

• Is it better to force my CPU to stay at minimum clock and idle less, stay at maximum clock whenever there's work but idle a lot more, or let the OS do its thing? (schedutil governor)
• Is it better to limit the system to one core or leave all 4 cores on? If it is better to limit to 1 core, can I do this without rebooting in Linux?
• Is it better to turn off GPU acceleration and let my CPU render things, or keep it on? (There are no integrated graphics, so the GPU cannot be turned off completely.)
• Is there anything else I can do that I haven't thought of?

[TheBean]

if this is an intel cpu, go to bios and disable speedstep. I think that locks you down to base clock. you could boot only 1 core but your pc would be painfully slow. disabling gpu rendering would probably help but it depends on the exact workload. 

 

best thing to do is just borrow from someone. 

[Zm1TDkSnQkY4KEqskCARSBpk]

7 minutes ago, Saksham said:

bios and disable speedstep. I think that locks you down to base clock

Just for clarification, by "base clock," do you mean the highest frequency that is not considered boost or the lowest frequency that the CPU supports? I think disabling speedstep will prevent turbo, but will also lock the CPU to the first definition of base clock even when the work load doesn't demand it. I can disable turbo boost as a separate setting, which would allow me to keep speedstep.

 

7 minutes ago, Saksham said:

best thing to do is just borrow from someone

For some reason (idk why, it's not a proprietary connector), only one other person in the entire school has a compatible power supply, and I only have one class with him on two days of the week. Today was not one of those days. Additionally, I also want to do this on car rides, where I don't have anywhere to plug in the laptop.

[TheBean]

2 minutes ago, Zm1TDkSnQkY4KEqskCARSBpk said:

I can disable turbo boost as a separate setting, which would allow me to keep speedstep.

thats what I meant. 

[Zm1TDkSnQkY4KEqskCARSBpk]

I don't think I was turbo-ing anyways. My CPU load never exceeded 50%. Disabling it just in case would probably help, but I don't want to have to reboot my machine, so I'll look into disabling it without rebooting.

[Enderman]

Reinstall your OS, preferrably use linux instead of windows.

That will get rid of a ton of stuff.

 

Also hibernate instead of sleep, and disable turbo boost or lock your CPU to a lower frequency.

[Zm1TDkSnQkY4KEqskCARSBpk]

1 minute ago, Enderman said:

Reinstall your OS, preferrably use linux instead of windows.

I'm already on Linux, and it certainly does help. Windows never lasted more than an hour just sitting on the desktop, and that was several years ago when the battery had less degradation on it, so I can confirm Linux helped. However, the run times I'm getting now are similar to what I'm getting just sitting in the BIOS, so I don't think an OS reinstall will help.

 

2 minutes ago, Enderman said:

hibernate instead of sleep

I'll consider it for longer periods of non-use, such as when I go to sleep, but it takes my system quite a while to wake up from hibernate, so in most cases, I'd probably be consuming more during that time than I would have saved over using sleep mode. Unfortunately, I don't have the exact power consumption of sleep mode and entering and resuming hibernate, so I can't calculate exactly when the cutoff is. Additionally, my laptop needs to be ready to go within a few seconds, and I cannot predict the exact moments that I will need it, so it will really only be useful during the lunch break (which I'm not sure is long enough to justify hibernate over sleep) and overnight (when I would definitely have the power supply, or at least the materials to macgyver one, anyways).