Screen Refresh Rate - Battery Life Effect

I only recently came by an obscure reference to the idea of reducing screen refresh rate from 60Hz to 40 Hz and reducing color depth from 32 bit to 16 bit to conserve battery usage rates. I just experimented for 90 mins. or so and based on several power monitor tools it appears that my Z13 running 50% brightness, Intel graphics, about 10 browser windows open including one running Neflix on the screen and a handful of power sucking processes including wifi and bluetooth an audio app, etc, (98 processes in all!) my extended battery was headed for about 6 hours which is at the higher end of what it usually runs for just moderate web surfing, no video, no bluetooth, approx. 80 processes. I would estimate that this run rate is at least 20% longer apparently due to these display changes.

Anyone have insights into this? I'll try running a more controlled test when I get a chance. I'm a bit skeptical about this rather crude test result because when I Google it there are few, passing references to this meaningfully increasing battery life.

 

Trying this out right now on my TZ..Have you made any change on the Power Settings as well..

 

I'm running in Power Saver mode of W7 with cpu throttled but my comparison was running this same power profile, which I almost always use when on battery for etxended times. Looking forward to hearing your results.

FYI, I am continuing the same test, now up to 110 mins or so and still tracking at 6-6.25 hrs on extended battery with 100% of original capacity. I've had this batt in a number of Z1's I've used for the past 9 months always limiting the charge to 80%, never letting it go below 10% (mostly not below 20%). I generally find it gets a bit less than double the time of the standard battery for the Z1 though it's exactly double the capacity, so this would translate to around 3.5 hrs on the std batt under this fairly taxing usage pattern, which would normally run the std batt down in 2-2.5 hrs. Caveat: all of this rough estimations.

 

I am traveling right now and using WWAN 100./. of the time...Also have set up to Balance Mode with screen at 30./....Batt charged at 80./....right now getting 5:10hrs running time although my batt wear reached 20./. after 3 years of usage..Have a spanking brand new in my bag just in case...will report after some more extensive usage....

P.S. My HDD is also switched off

 

Cool. For comparison purposes, it will be best to have settings and usage patterns similar to ones you often use and know the battery performance under. You might want to do a couple of hours with the new battery with normal screen settings and then a couple of hours with reduced screen settings.

 

I just wonder how much more drain on batt would WWAN have over WIFI..II wll try both

 

From my experience (on the Z and Z2) lowering the refresh rate and color depth does indeed increase battery life.

 

Cool beans! A member of the NBR Sony Forum "Brain Trust" confirms my wishful thinking! Care to hazard a guess as to the % gain, ballpark estimate? Which is more significant, the refresh rate or the color depth - or does that depend on what's on the screen for most of the time?

 

Did my testing yesterday throughout the day...
I can say that I got extra 45 min using the modified refresh rate 16/40..

 

Outstanding. Just a couple questions. About what % increase is that on your TZ? Was that improvement achieved with your normal usage patterns, no other changes made that affected energy consumption? Also, did you notice much effect on the display - color depth, motion fluidity? I did notice an occasional momentary pause when scrolling a full page at a time but otherwise no "side effects;" found streaming HD video, even some extreme sports loops with vivid colors, looked fine.

Extracting well over an hour more battery time out of my Z13's extended battery feels like transplanting the next gen's cpu into my "aging" laptop. Kinda the opposite, really: 1) spend a buncha bucks in 2010 getting fast cpu, discrete gpu, vividly bright and colorful screen, 2)figure out how to gimp it down to the specs of a 2007 laptop to get the battery life of the 2011 version!

Conclusion: I seriously need to get a life! (Planning to after some health issues get sorted out soon. )

 

My setup for this experiment was

Battery charged @ 80./.
Power management - balanced / CPU fan level 1(quiet)
Memory bus : 400 MHZ
Screen brightness 30./.
WWAN ON 100./.
Sound off/mute - whenever not steaming video/music
2nd HDD - off

A) ./. increase - 20
B) yes it was on normal usage
C) colors - I am colorblind and may not have noticed any changes