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Screen vs CPU and battery life

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Anonymous
a b à CPUs
February 13, 2005 8:15:15 PM

Archived from groups: alt.comp.sys.palmtops.pilot,comp.sys.palmtops.pilot,uk.comp.sys.palmtops (More info?)

What uses up the battery most on a T3? The screen or the CPU? What is the
proportion of energy used by each?
I watch movies (and TV programs) on the T3 which are stored on an SD card,
using MMplayer. If I start with the T3 well charged, I am surprised how
little of the battery life is used after 1 or 2 hours considering I am
viewing in 480x320. It often seems to me that I get a far longer runtime
from continuous movie watching than from everyday use.
I am trying out Lightspeed (an overclocking utility) because increasing the
CPU speed (from 400 to 600) may be useful when watching movies; a process
which stretches Palm hardware to the limit. When I do so, the battery life
drops sharply, perhaps to 30 minutes.
I would expect overclocking to use more energy, but I am surprised by the
drop in battery life. It implies that the CPU uses up a very significant
proportion of the battery life.
Anyone know about this in detail?
Mick
Anonymous
a b à CPUs
February 13, 2005 8:15:16 PM

Archived from groups: alt.comp.sys.palmtops.pilot,comp.sys.palmtops.pilot,uk.comp.sys.palmtops (More info?)

Penster wrote:
> What uses up the battery most on a T3? The screen or the CPU? What is
the
> proportion of energy used by each?

> I am trying out Lightspeed (an overclocking utility) because
increasing the
> CPU speed (from 400 to 600) may be useful when watching movies; a
process
> which stretches Palm hardware to the limit. When I do so, the battery
life
> drops sharply, perhaps to 30 minutes.
> I would expect overclocking to use more energy, but I am surprised by
the
> drop in battery life. It implies that the CPU uses up a very
significant
> proportion of the battery life.
> Anyone know about this in detail?
> Mick

Rechargable batteries will deliver more amp hours if they are not
loaded as hard. In other words, a battery could deliver, for instance,
100ma for 10 hours. So you might think if you put a heavier load on the
battery such as 200ma (double) then it ought to last 5 hours (half).
But, it will not. Conversly, if you reduced the load to only 50ma
(half) then it will actually last longer than 20 hours (double).

So increasing screen brightness or increasing processor speed does in
fact shorten the usable runtime of the battery more than might be
expected. The converse is also true.

If a rechargable battery is rated at 1000 mAh that implies it should
produce 100 miliamps for 10 hours OR 10 miliamps for 100 hours. But the
actual ratings are based on a standard discharge rate of a 20 hour time
period. Therefore this 1000 mAh battery will probably produce 10 ma for
MORE than 100 hours. At the higher discharge rate of 100 ma it won't
even last the mathematical 10 hours.

Another way to say it is- if you cut the current draw in half you will
get MORE than twice the usable time from the battery. If you double the
amount of current being drawn you will get less than half the usable
time out of the battery. And, the more the current draw the more severe
this becomes. It is not linear.
Anonymous
a b à CPUs
February 14, 2005 11:00:29 AM

Archived from groups: alt.comp.sys.palmtops.pilot,comp.sys.palmtops.pilot,uk.comp.sys.palmtops (More info?)

Thanks. That explains it very well.
Mick
<pailfaced88@yahoo.com> wrote in message
news:1108334859.794707.72930@z14g2000cwz.googlegroups.com...
> Penster wrote:
> > What uses up the battery most on a T3? The screen or the CPU? What is
> the
> > proportion of energy used by each?
>
> > I am trying out Lightspeed (an overclocking utility) because
> increasing the
> > CPU speed (from 400 to 600) may be useful when watching movies; a
> process
> > which stretches Palm hardware to the limit. When I do so, the battery
> life
> > drops sharply, perhaps to 30 minutes.
> > I would expect overclocking to use more energy, but I am surprised by
> the
> > drop in battery life. It implies that the CPU uses up a very
> significant
> > proportion of the battery life.
> > Anyone know about this in detail?
> > Mick
>
> Rechargable batteries will deliver more amp hours if they are not
> loaded as hard. In other words, a battery could deliver, for instance,
> 100ma for 10 hours. So you might think if you put a heavier load on the
> battery such as 200ma (double) then it ought to last 5 hours (half).
> But, it will not. Conversly, if you reduced the load to only 50ma
> (half) then it will actually last longer than 20 hours (double).
>
> So increasing screen brightness or increasing processor speed does in
> fact shorten the usable runtime of the battery more than might be
> expected. The converse is also true.
>
> If a rechargable battery is rated at 1000 mAh that implies it should
> produce 100 miliamps for 10 hours OR 10 miliamps for 100 hours. But the
> actual ratings are based on a standard discharge rate of a 20 hour time
> period. Therefore this 1000 mAh battery will probably produce 10 ma for
> MORE than 100 hours. At the higher discharge rate of 100 ma it won't
> even last the mathematical 10 hours.
>
> Another way to say it is- if you cut the current draw in half you will
> get MORE than twice the usable time from the battery. If you double the
> amount of current being drawn you will get less than half the usable
> time out of the battery. And, the more the current draw the more severe
> this becomes. It is not linear.
>
March 3, 2005 2:55:38 AM

Archived from groups: alt.comp.sys.palmtops.pilot,comp.sys.palmtops.pilot,uk.comp.sys.palmtops (More info?)

anyone know where to get T3 replacement batteries from??

Paul
"Penster" <xxx@xxx.com> wrote in message
news:xUYPd.154$hL3.15@newsfe2-win.ntli.net...
> Thanks. That explains it very well.
> Mick
> <pailfaced88@yahoo.com> wrote in message
> news:1108334859.794707.72930@z14g2000cwz.googlegroups.com...
>> Penster wrote:
>> > What uses up the battery most on a T3? The screen or the CPU? What is
>> the
>> > proportion of energy used by each?
>>
>> > I am trying out Lightspeed (an overclocking utility) because
>> increasing the
>> > CPU speed (from 400 to 600) may be useful when watching movies; a
>> process
>> > which stretches Palm hardware to the limit. When I do so, the battery
>> life
>> > drops sharply, perhaps to 30 minutes.
>> > I would expect overclocking to use more energy, but I am surprised by
>> the
>> > drop in battery life. It implies that the CPU uses up a very
>> significant
>> > proportion of the battery life.
>> > Anyone know about this in detail?
>> > Mick
>>
>> Rechargable batteries will deliver more amp hours if they are not
>> loaded as hard. In other words, a battery could deliver, for instance,
>> 100ma for 10 hours. So you might think if you put a heavier load on the
>> battery such as 200ma (double) then it ought to last 5 hours (half).
>> But, it will not. Conversly, if you reduced the load to only 50ma
>> (half) then it will actually last longer than 20 hours (double).
>>
>> So increasing screen brightness or increasing processor speed does in
>> fact shorten the usable runtime of the battery more than might be
>> expected. The converse is also true.
>>
>> If a rechargable battery is rated at 1000 mAh that implies it should
>> produce 100 miliamps for 10 hours OR 10 miliamps for 100 hours. But the
>> actual ratings are based on a standard discharge rate of a 20 hour time
>> period. Therefore this 1000 mAh battery will probably produce 10 ma for
>> MORE than 100 hours. At the higher discharge rate of 100 ma it won't
>> even last the mathematical 10 hours.
>>
>> Another way to say it is- if you cut the current draw in half you will
>> get MORE than twice the usable time from the battery. If you double the
>> amount of current being drawn you will get less than half the usable
>> time out of the battery. And, the more the current draw the more severe
>> this becomes. It is not linear.
>>
>
>
!