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Getting the most from your Battery.

Biolapse

New Member
Hello everyone!

I have the Surface Book, i5, 8g, 256g, w/dGPU.

I have had some issues with battery drain with my Book. I wanted to spend some time getting a better understanding of the power settings and what to expect.

I ran a series of informal tests and here are my overall results.

On my tests I would simply mark the time, close the lid, and wait 2 hours, then open it back up and see how much battery drained with the current settings. I did this over a dozen times and here are my results.

I found that when in SLEEP mode I would end up using about 5% battery per hour. It does not matter if Windows Hello is on or off, same with the Wifi on sleep.
Windows Hello = ON or OFF
Wifi when sleep = ON of OFF
Hibernation = Never

I found that by enabling Hibernation the battery drain while not in use drastically improved.

Hibernate after 10 min sleep = 1% drain after 2 hours of inactivity.
Hibernate after 30 min sleep = 2% drain after 2 hours of inactivity.

I suspect once it hits hibernate that is where all the battery savings really come from, and the extra depletion from the 10 vs 30 min of sleep would remain the same for longer periods. I did run one test with Hibernate after 10 min of sleeping and it still only lost 1% after 6 hours of sleep.

this tells me the Battery depletion virtually STOPS when it hits Hibernation mode.

So the big difference between Sleep, Hibernate, and Off?

Sleep draws a few watts of power the whole time. When listing the screen it only takes 3-4 seconds from the open to logged in with Windows Hello.

Hibernate takes a snapshot of your desktop and programs and seems to actually shut down. When opening the screen it does not immediately try to turn back on, and I have to press the power button. On average it takes 15 seconds to boot, and all my applications and programs are just where I left them.

Off, well.. its Off.

So which is better? That is a personal question. I do like Windows hello and do not want to have to sign in. The SSD allows a snappy 15 seconds between pressing the power button to fully logged in which I find to be far more desirable than to have my laptop closed and on the counter for 4 hours to find I lost 20% battery. That to me, is unacceptable.

Leaving Hibernation at 30 min seems to be a nice sweet spot. It allows a bit of a buffer of time to grab it and have it immediately start vs cold boot.

I would really like to see microsoft find a way to lower the battery drain while in sleep, but for the meantime this seems to be a big improvement. I am more concerned about preserving battery while in commute, or while not in use than I am saving 10 seconds to log in. 15 is pretty damn quick if you ask me. If this was a HDD based system this would not be a very good option.

Notes:
I have the updated battery drivers
I have occasional driver crashes
Once when rebooting i had to reboot to the bios to get in
My screen never had flicker issues, color shift issues, or any of that
I have installed the latest Nov 18 firmware update before testing.
Once (only once) I closed the lid and commuted home, an hour later my battery was totally depleted. I estimate it was at about 60% before i closed the lid. Not sure WTF that was about.
Battery performance when in use has been fantastic. If I am cranking out some 3d modeling in Designspark, or crunching 4k timelapse video in Adobe battery certainly suffers, but that is to be expected. I am at 74% right now and have spent the last 3 hours surfing the web and blogging. Thaat seems to fall in line with 12 hours expected for non processor intensive use. 39% screen brightness.

I would love to see other people test this out and post their results.
-Chris
 
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