[Arm-netbook] Power consumption

[Teis Dreijer]

On Thu, 2010-03-04 at 12:38 -0500, JLB wrote:
> Personally, I haven't been too happy with my battery life. It seems to run 
> down faster than it ought. I haven't timed it yet, but it just "feels" too 
> drain-y. Then again, I'm used to my ginormous 9-cell whopper on my MSI 
> Wind...
IIRC its powered by a ~7½Wh(?) battery, so +3 hours at max (?) brightness is very impressive.
In comparison my ~3" SE Satio phone runs dry in day on a 3.6Wh battery
with about 30minutes of active usage (3g on, max brightness etc.).
My 14.1" thinkpad with a gigantic 84Wh (9cell) battery does 5-6hours
with medium brightness, igp, wifi on, firefox (ouch!) and an ever
spinning harddrive.

NiHM AA batteries can each carry about the same as this netbook if it
indeed only has ~7½Wh on each charge (which I am beginning to doubt,
somehow I've got a memory of it being 2100mAh). They are cheap and can
be charged outside of the netbook, usually with a 20usd 4 slot charger.
Easy to dispose of and replace whenever they are worn down, so this is
something I'm going to look into once I find a screwdriver that fits and
have time to crack it open.

 - Maybe dropping the counterweight in the front will make even more
room for a bit of modification? I've got my DMM ready, so we will see
how complicated/simple a battery mod would be. Obviously I will have to
check for some sort of battery level indicator if I choose to go ahead
with the AA/AAA battery idea.

For now, killing the screen manually whenever its not needed did wonders
for me: sleep 1; xset s activate
After all I guess the screen is what sips the most juice.

> I'll get some timing data, maybe, but I wonder if I could hack in a 
> battery with more mAh worth of capacity....

Please remember that the kernel is 'bad' and spews out lots of errors to
dmesg. I recall someone saying this would probably use a noticeable
amount of resources. I'm hoping hw accelerated pointer and adjustable
screen brightness will make a difference too.

Teis