Wednesday, May 28, 2008

Asus Eee PC 900 battery life

Battery life is one of the most important feature on mobile computer. That's why I have been doing some testing with my Eee PC 900..

Continue reading..

These test were done under full load, using Battery Eater.
I disabled all battery savings, brightness was at 100% and wifi was on.
I also disabled standby at 10% so these numbers show the results from 100% to 0%.

You can use Eee PCs at 630Mhz or 900Mhz and these tests clearly show the difference.

You can get easily 30 to 50 minutes more battery life by setting the cpu speed to 630Mhz from either BIOS ( 0302 ) or with eeectl software.

The second difference on battery life can be seen on this diagram:

It jumped from 40% to 10% in 2 minutes...

After I disabled the default "shutdown at 10%" I got 30% to 40% more battery life!

Typically laptops are set to shutdown or sleep at 3%, but for some reason Eee PCs can only be set to do it at 10%. Worst part is that as Asus battery meter is so inaccurate it may shutdown your computer when it thinks there is only 10% left, even it can be 30% to 40%.

Not good Asus! They really should fix this.

Mix this with the news that Eee PCs are shipping with different sized batteries in different countries... not good..

As for the batteries, I can highly recommend:
Mugen 7800mAh for best size vs power option
MonoMobile 5200mAh for second battery ( about 50 dollars )
MonoMobile's new Super Large 10400mAh for extreme need ( 5 hours 45 minutes on full load test! )

Eee PC batteries at

Related News:


Vic said...

Thx for the tests!

From Hong Kong EeePC website:

Click 電池 [battery]

"6 cell ,7800mAh (5.5 x 4 x 14cm) *

*即將上市 [coming soon]"

Looks like ASUS will introduce a new battery. Let's hope the prices will get cheaper with more choices.

Anonymous said...

Thanks for the super test, this is the kind of data I needed. I have a Eee 900 with 5800 mAh Akku and was leaning towards the 7800 mAh Mugen, this setteled it for me, jkkmobile in the House as always.


Mike Cane said...

Hmmm ... I wonder now if this is why there's a rumor of the e900 being discontinued RIGHT NOW to make way for the Atomed e901 and its better battery life?

Thanks for those tests. I've been waiting for that news.

Unknown said...

It's important to remember that those times are at 100% load. The fact that the underclocked 900 running a 7800mAh lasts for over four hours at full load is outstanding! Under normal conditions that is a very long life battery.

Great test JKK.

Unknown said...

hey thanks for the tests i was wondering how to disable the auto shut down?

Unknown said...

Fantastic info

JKK i just purchased a eee 900 today, i was wondering if you had any start up tips for a new coming - for example essential downloads and general news.

get back to me

Anonymous said...

There are several steps you can take to help you get maximum performance from your laptop battery: Prevent Memory Effect - Keep the laptop battery healthy by fully charging and then fully discharging it at least once every two to three weeks.

Anonymous said...

Have you done a comparison between the Mugern 7800 and the mono-mobile 7800 just wondered if there is any significant differance.

Anonymous said...

Thank you,Here is another tip for you. Just keep your laptop turned off, and your laptop battery will stay fresh.

Anonymous said...

very good,many customers ask me how to extend your laptop battery life,then I can interview they to here now。

Anonymous said...

If you are not going to use laptop for few days, then discharge the battery fully and disconnect it.

Anonymous said...

Use the laptops power management system. This application will help optimize power usage.

electron said...

Here's what I did to maximize the battery time whem I'm using GPS : I turned off the stand by function on closed lid so the system is still runing even if the display is off. This way I can hear the lady giving me directions for a lot longer time

Anonymous said...

Actually, fully discharging a Lithium Ion battery can shorten its life. If not used for a while it should be stored with about a 40% - 50% charge.
Even under use, never fully discharge the battery to 0 % charge. It is not like some other types of rechargeables where you might do that to prevent memory effect.

JKK said...

Actually, fully discharging a Lithium Ion battery time to time keeps it in better condition.

By "fully" i mean letting it discharge on computer.

the other "fully" discharging would mean using other methods like placing a led or something else to battery pins, which is not a good way..

Anonymous said...

Exercise Your Battery - Do not leave your battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks. If a battery has not been used for a long period of time, perform the new battery break in procedure described above.

Anonymous said...

I thought LW was the best technology for laptop battery performance.

Anonymous said...

We have huge inventory of laptop batteries for Sony, IBM, HP, Compaq, Apple, Dell, Gateway, Panasonic and more.

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