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From: Jeff Liebermann on 10 Feb 2010 16:08
On Wed, 10 Feb 2010 10:54:43 -0800, John Navas
<spamfilter1(a)navasgroup.com> wrote:

>On Sun, 07 Feb 2010 20:52:41 -0800, Jeff Liebermann <jeffl(a)cruzio.com>
>wrote in <2d3vm55p50pb5od8ntdokrikkf6oveg84n(a)4ax.com>:
>
>>On Sun, 7 Feb 2010 19:08:20 -0800, "Mike Jacoubowsky"
>><MikeJ(a)ChainReaction.com> wrote:
>>
>>>"Up to 10 hours of surfing the web on Wi-Fi, watching video, or listening to
>>>music Up to 10 hours of surfing the web on Wi-Fi, watching video, or
>>>listening to music" (from Apple's website).
>>
>>I've found that a new battery meets or exceeds Apple's published
>>specifications.
>
>I sure haven't -- I've found the iPhone numbers to be quite optimistic,
>on the order 2x actual performance with a brand new battery.

No clue on the iPhone. However a new iPod Touch battery was fairly
close to Apples claims. There are huge variabilities in how people
use these things. I know one sales personality that is yacking on his
iPhone constantly. He complains that the battery won't make it
through an 8 hr day (plus his commute). I'm not surprised. Others
mention that they charge theirs every 2-3 days. There are various
apps that can predict battery life based on past usage. I have one
and it's fairly accurate.

We also have a unique problem in my area. Coverage from all the
providers in the San Lorenzo Valley is spotty. If you spend some time
in places where there's no coverage, the stupid phone will "hunt" for
a suitable cell site. This runs down the battery. I'm sure it
happens with Verizon (because that's what I use), but apparently, it's
also a GSM problem. Without a cell site to keep the phone inactive,
my battery is dead in about 4 hours without ever having made a call.

>>However, battery operating time deteriorates with
>>Li-Ion batteries as the battery ages.
>
>True, but not very rapidly -- life is on the order of 2-3 years before
>half capacity is reached, an average degradation of only about 2% per
>month.

Nope. It's way more complexicated than that. Deterioration is
heavily dependent on temperature and state of charge:
<http://drc.ohiolink.edu/handle/2374.OX/103486>
<http://www.electrochem.org/dl/ma/202/pdfs/0033.PDF>
Plenty of others available. Google for "Li-Ion battery capacity fade"
or capacity loss, deterioration, etc.

>>Battery life also deteriorates more rapidly if you maintain a Li-Ion
>>battery at maximum charge, and bake it inside a laptop or heat
>>generating device. No clue yet how warm the iPad will run. More:
>><http://www.batteryuniversity.com/parttwo-34.htm>
>
>That's not a terribly accurate source.

Ahem... Isidor Buchmann is the founder and prez of Cadex, a
manuafacturer of battery chargers and analyzers. I have one of their
chargers and it's excellent. He's the author of a book on the subject
which is generally recognized as authoritative:
<http://www.buchmann.ca>
<http://www.buchmann.ca/aboutauthor.asp>

Incidentally, I have a West Mountain Radio CBA-II battery analyzer:
<http://www.westmountainradio.com/CBA.htm>
I've found that battery capacity varies considerably from vendor to
vendor. Some barely achieve the labelled specifications. Others
exceed the specs by as much as 75%. Many vary dramatically in
capacity depending on discharge rate. Never mind user variability,
there's also large variations in capacity.

One catch. I can't reliabily test the larger laptop batteries. The
CBA-II is limited to about 100 watts discharge rate, which is about
what one of the older wide screen "desktop replacement" laptops burn.

>>It might also be of interest to know the battery life for the latest
>>Windoze 7 touch screen laptops is claimed at 3 to 5 hours:
>><http://www.computerworld.com/s/article/9140385/Review_3_Windows_7_touch_screen_laptops>
>>(4 pages)
>
>Battery life varies widely between different machines and between
>different types of use -- the real world range is much wider than that.

There are several commercial battery life test suits available. In
all cases, the laptop initial conditions and test applications are
carefully defined so that the comparisons are valid. For example:
<http://reviews.cnet.com/Labs/4520-6603_7-5142378-1.html>
There are others, but I'm late for lunch.
Not everyone is happy with the defacto testing methodology:
<http://bits.blogs.nytimes.com/2009/06/17/why-cant-we-get-an-accurate-battery-life-test-for-laptops/>

>Case in point is my ThinkPad T61, which gets nearly double the battery
>life when I carefully configure the power management for maximum battery
>run time.

I run my laptops at maximum CPU, maximum brightness, and everything I
can possibly disable. I want speed, brightness, ease of use, and
convenience. I fry a laptop battery about every 3 years, which is
about typical.

What I *DON'T* do is leave the laptop on charge 24x7 cooking the
battery inside the laptop. After about 3 years, the battery has
become sufficiently common that the eBay prices are about $50 or 1/3
of the cost of an OEM battery. I also have a small collection of
nearly dead batteries, which are good baking when used with the
charger running.

--
Jeff Liebermann jeffl(a)cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
From: alexd on 10 Feb 2010 16:38
Meanwhile, at the alt.internet.wireless Job Justification Hearings, Jeff
Liebermann chose the tried and tested strategy of:

> Now, if Apple included a printing application with the iPad, it could
> become a background process, which will be much better. However, I've
> seen no evidence of such an application on the iPad or iPod Touch yet.

They bought the developer of a Unix printing framework called CUPS, so that
sounds like the obvious choice.

--
<http://ale.cx/> (AIM:troffasky) (UnSoEsNpEaTm(a)ale.cx)
21:37:16 up 6 days, 2:17, 6 users, load average: 0.06, 0.03, 0.00
DIMENSION-CONTROLLING FORT DOH HAS NOW BEEN DEMOLISHED,
AND TIME STARTED FLOWING REVERSELY

From: Mike Jacoubowsky on 11 Feb 2010 01:37
"Jeff Liebermann" <jeffl(a)cruzio.com> wrote in message
news:qbt0n5p3q8pbdl23kg0lujhinjhhidvc1s(a)4ax.com...
> On Sun, 7 Feb 2010 18:23:09 -0800, "Mike Jacoubowsky"
> <MikeJ(a)ChainReaction.com> wrote:
>
>>I can assure you that, after Apple's iPad announcement, the
>>bicycle retail e-list was abuzz regarding the use of tablets as roaming
>>point-of-sale terminals.
>
> Umm... what are you going to do for printing receipts? In the state
> of Calif, you're required to give a receipt if you charge sales tax.
> If the iPad is anything like the iPod Touch, printing is handled by
> 3rd party applications, usually in some bizarre manner. Others will
> only do photos, not ASCII text. For example:
> <http://www.hp.com/global/us/en/consumer/digital_photography/free/software/iprint-photo.html>
> Epson and Canon have similar apps.
>
> There's a free test applications for Print Magic which does apparently
> does ASCII text that's worth trying:
> <http://wellala.com/printer_test_app>
>
> --
> Jeff Liebermann jeffl(a)cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558

I remember being very surprised that the Apple store could get away with not
printing receipts when I purchased something, saying they'd email it.
Without any way of knowing if they'd entered my email correctly (they did).

Doesn't matter for how we'd use an iPad anyway. I thought I'd mentioned that
we'd be using them as nothing more than remote terminals. Printing would be
handled by the host computer.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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