Hi,

I've covered a little of the exploration of this in another thread here. Unfortunately no replies.

I've now installed as many power-saving features as I can get to work including laptop-mode scripts and my Asus Eee PC 900 has the battery lifespan of a gnat (2 hours 39 mins of extremely light usage including a long period of inactivity although with wireless turned on, from fully charged to battery cutting out, annoyingly this time ignoring my script that registers a critical battery APCI event and shut it down safely).

So, basically is my new Asus Eee PC 900 the worst designed netbook ever, or is linux just not supporting it's power-saving features? It is actually the version that comes with Asus's own linux distribution on it, but I've installed Arch.

The battery is admittedly pathetic, but surely the point of a Netbook is it's minimal power consumption:

What power-saving features I've found that work on the EeePC 900:

• usbcore autosuspend I assume this is working I passed a parameter to the module without complaint.
• lcd blank Laptop-mode turns off the lcd after a few mins inactivity.
• lcd brightness Brightness is set to 6 out of 15 when on battery.
• acpi-eeepc-generic Scripts to gain use of EeePC function keys. Including the Wireless off button, however this required a rewrite of some of the core functions of scripts as the first time it was pressed wlan0 would turn itself off then immediately back on again. This is apparently down to the BIOS doing the unloading itself! (Seems to be the case as disabling all the functions to turn off the wireless still results in it being disabled and restored as expected, so scripts now just notify user and reload wicd.

What it seems like I can't use:

• cpu freq scaling This module has been removed from TooFish's EeePC kernel as the Intel(R) Celeron(R) M processor 900MHz apparently doesn't support this feature.
• S.H.E. I found that instead my model is supposed to save power by using something called SHE which is supposed to be available on the EeePC. However after following the appropriate instructions to get SHE working I found that it listed a state (/sys/devices/platform/eeepc/cpufv) of 0x200 which apparently means that the powersaving mode is unavailable for my unit. However I did change the laptop-mode to switch from SHE mode 0-Performance to mode 1 which is variously described as Default and Normal.
• wireless power-saving modes I've tried a number of ways to get power-saving on my wireless card none of which appears to be supported. I'm using an ath5k module for my card (AR5001). iwpriv lists wlan0 as having no private ioctrls which stops me entering a number of the power-saving commands I've found. I also tried setting the timeout (iwconfig wlan0 power timeout all 500m) but get an error operation not supported.

What then are the power-saving options left available to me? How can I extend my battery life to long enough to check an email? What out of what I've said ins't working that really should?

You don't mention which PC 900 model you have, but according the Asus website, the spec battery life is between 2.5 and 3.3 hours, depending on the model.

This one, for example, specs at 2.5 hours.

It isn't a bad netbook, just an old one. It was one of the early ones, before the Atom was wide spread and before high efficiency northbridges. A lot has happened in the netbook market since early 2008, back then 2-3 hours was pretty much standard. They were also trying to make them as cheap as possible, so they had fairly small batteries.

I waited until late 2008 to jump on netbooks, I bought an EeePC 901, which has an Atom, SSD, a high capacity battery, but still has the old Intel 945 northbridge that is not very efficient. I can manage 5 hours from it, still a far cry from the 8-10 hours being common today.

You could get an 11,000mAh battery to replace the stock one, which I believe was around 4400mAh, but those are bulky.

Yes, that's the one I have, the linux version that is. So we're leaning toward yes it is the worst netbook ever.

I would say though that at the moment describing the battery life as 2.5 hours on my setup is a taking a liberty, as I said my test did last for 2h39m but that was till the battery cut out. Stopping it safely would cut a few minutes off that, also it involved 40min + of non usage during which the screen was blanked, and I'm running a very minimal install with openbox.

Interestingly it says the tests on the EeePC was done with SHE, although it seems that it's a generic page describing the test.

Well, thanks for the replies. I suspect that it is just the age of the hardware, and I have to say as an upgrade from my G4 1GHz PowerPC running Gentoo with broken PSU that killed batteries 2 1/2 hours is a big improvement.

The battery upgrade looks like an option if I find that the short lifespan is getting to me, looks like I can get a 10400mAh one for £29.99 (that's half again as much as the laptop, but there you go). That should supply twice the power, hopefully extending it to an awesome 5 hours.

I've read the test used for the figure of 2.5 hours quoted by Asus and it's an average score of two tests to battery failure. Both in Asus' case have WiFi off, but one is a minimal power consumption, ldc backlight off, not doing anything, the other is loaded (slightly) with lcd brightness at a set luminosity (I don't know how high that is) continuously playing a small MPEG (320x240) from disk. Both tests have the sound in mute! (So it's not much of a test from an actual usage perspective.)

I still think my current configuration sores very well against this, but I suppose I've explored my power-saving options.

I do think you are being a little hard on it. The Asus eee PC900 is almost four years old.

It was one of the earlier netbooks. Back when netbooks were new, three hour battery life wasn't all that bad.

This Wikipedia article indicates that there was some controversy about the stock battery in the first UK version:

http://en.wikipedia.org/wiki/ASUS_Eee_PC#Eee_900_series

So you paid £60 for an old netbook and expected it to be like a new £300 netbook? I think you got a pretty good deal, I paid close to that for my little 7" EeePC 700 2G Surf with a 570mhz processor, 512mb of RAM, a 2gb SSD and the same battery as yours, it is perfect for what I bought it for.

elliott678, I agree and I'm not being as harsh as people seem to think I am, I was being a little provocative in the title to get some replies as my last discussion of power-saving features died.

I have a new battery and apart from being massive - it sticks out about an inch further than the original - it lasts a mile longer.

Interestingly it reports a battery state of:

Which makes me think the design capacity reported may be hard coded, so the original battery could in fact have been one of the UK 4400 mAh batteries, also there appears to be a BIOS update that claims to improve battery life. Since it's never had a BIOS update I suspect it's not had this one.

One other thing, even though I'm quoting a discharge time of 2 1/2 hours, it is actually much more disturbing than that to watch as it spent by far the longest time while on battery reporting 20% capacity. So it would report discharging 80% of it's battery in the first 40 mins of use and start flashing the battery warning light at you.