Battery experience...

Saw a great article in this week's Newsweek on manufacturer's battery claims. See...

http://www.newsweek.com/id/202572

I have to say I'm a bit disappointed in the 3 cell performance on my 11.6". On a fully charged battery, I see something slightly less than 3 hours. Then, after a little use, I notice the gauge is hovering around a little over one hour. To be fair, I haven't tried running it all the way down to see how long the 3 cell really lasts. I probably would have bought a 6 cell model if one had been available. And to be honest, I don't really have a need to be that far away from a fresh charge.

I guess I'm really concerned that if I were to take it on a flight, I might not have enough juice to get through a 2 hour movie if the battery is not fully topped off.

On the other hand, I had a 8.9" with a 6 cell battery and it definitely felt heavier. This computer is a joy to pick up. On balance, I think this model could very easily end the production on all the earlier Acer netbooks, especially if Acer comes out with one with a little more horsepower.

I would be interested in hearing from other users about what they're getting out of this 3 cell.

 

i get around 3 hours and 10 minute on my battery, using it as web browsing for around an hour, installing new programs, and then watch a 40 minute video with wifi off, i basically recharge my battery around 5% battery life left.

 

Well, that's encouraging to hear. Hope my 3 hour battery does as well.

 

I've been experimenting a bit with battery consumption to maximize runtime. I've got the 6-cell battery, but I would really like to make it last the marketed 8 hours
I use the Notebook Hardware Control battery usage meter, which shows an approximate energy usage in watt. It is probably not extremely accurate, but seems good enough for this use.
To achieve 8 hours on a 6 cell battery (or around 3,5 hours on a 3-cell battery) , average energy consumption needs to be approximately 6,5-7 watts

My findings so far are:
* Screen brightness matters. Lowest level uses appx. 0.3 watt. Highest brightness level uses appx 2.8 watts. After a period of inactivity and screen turned off, I believe the GMA 500 also turns off, which saves another watt or two. Nice, but obviously does not happen if you actually use the computer.
* WLAN on/off and setup matters. I've found the drivers to be rather messy with regard to power usage. I'm not sure whether it's the wlan card itself or the pcie interface which is the problem. Some drivers seem to use around 0.7 watt extra for an idle wlan (a lot more for actual transfers, of course), while some use 1.3 watt. I've installed the atheros modded drivers (which was a bit cumbersome), and seem to be down to about 0.3 watt for wlan when idle. The WLAN will still vary a lot, with 1-1.5 watt peaks from time to time. Note that it seemed like some drivers causes the wlan to use power even if you turn of the wlan switch. Disabling it in device manager sometimes makes a difference.
* The laptop uses an extra watt forever when it recovers from standby (!). I believe this is an issue with the wlan pcie interface. I've "fixed" this by using hibernate instead of standby. Would be excellent if someone else could verify this. Could just be something with my setup or computer, but if not this should possibly be reported back to Acer.
* Hard disk only uses appx. 0.5watt when idle. It obviously uses 0w if you can make it spin down, but that does not happen much during normal use, unless you are willing to do some serious setup modifications.
* USB disks uses appx. 1 to 1.5 watts when connected.
* I believe the ethernet connection in its default setup uses a bit of power even when not connected. Can be disabled in device manager if you are not using it.
* SD-cards uses appx. 1 watt when active. However, they turn off after somewhere around 3 minutes.
* CPU will use up to a watt extra when on 100%. Keep down background processes. Possibly use a flash blocker, as a lot of flash ads peaks the CPU.
* Fan uses 0.2-0.3 watt. Can be regulated with aa1fancontrol
* Do not start these kinds of measurements if you have my obsessive personality. Your wife will find you by the netbook at 3 in the morning, yelling "Now what?!" whenever the battery drain graph peaks for no apparent reason.

I think I'm down to about 6 watts when doing regular surfing on the second brightness level. (The first level is just too dim at daytime, even inside).

 

New rules: do not disable the ethernet connection - the laptop will use an additional 0.5 watts when recovering from suspend for some reason. Also, install the realtek soundcard drivers also for windows7, even if it seems to work without them...the default drivers due not switch of the audio when idle, and uses additional 0.3 watts continuously. The important points for maximizing battery runtime are therefore (time estimates based on a 6-cell configuration lasting appx 8 hours, should be halved for a 3-cell configuration):
* Max brightness will cost appx. 2 hours runtime compared to minimum brightness
* Wireless will cost appx. 0.5-2 hours, depending on configuration/driver choice/usage
* High cpu-usage (e.g flash-intensive pages) will cost appx 1.5-2 hours
* Using suspend instead of hibernate will cost appx. 1-1.5 hours due to weird higher power usage when resuming. Someone else should verify this finding...
* Not having the proper audio drivers installed: 0.3 hours

 

Eatch time you "test" this stuff you need to recharge and when you recharge its less time the battery will last you.
and remember lithium-ion batterys provides 300-500 discharge/charge cycles!!!
its Not wise to keep dischargeing them for no good reason.

Read Here:
http://www.batteryuniversity.com/parttwo-34.htm

 

Hello,
thanks for your findings.
I see that your "modded" atheros drivers can get wlan idle wattage by half.
Can you share the driver please?

 

Sure: http://forums.laptopvideo2go.com/topic/ ... and-winxp/

The drivers does pretty much the same as the regular, but has a lot more options for fine-tuning in the device manager. I believe the main benefit in idle wattage is to turn the "pcieaspm" to ON/ON. This seems to work fine for me. I believe it powers down the pcie-slot when idle. Or something like that...

 

Thanks for your help.
I recently found out my battery (6cell) has 15% wear. i'm trying to save battery now.

 

How did you determine the 15% wear? Seems like a lot for a computer that just came out a few months ago.

 

I used battery bar, it showed me i had 15% wear.

I have AOA150 since sept

 

Oh yeah, in addition to the points above, do upgrade the chipset drivers and the Intel GMA drivers from the Acer support page. One of them actually cuts 1,5Watts (or appx. 2 hours) IF you do not use the suspend feature. Probably a driver bug. Instead of suspend, use hibernate or turn the thing fully off.
EDIT: As c921 found, the new bios 3208 seems to cut appx. 0.3 to 0.4w, giving an improvement of 0.5-1 hours.
I also noticed that having the dolby headphone-function enabled uses 15%-20% cpu when playing sound. This shortens battery time, but more importantly taxes a CPU which is often the bottleneck. Turning dolby headphone off gives noticably better youtube-performance, for instance.