[Discuss] My God! It's Full of Batteries!

[gaf at blu.org (Jerry Feldman)]

On 03/16/2012 10:17 AM, Richard Pieri wrote:
> iFixit got their hands on one of the first The New iPads (by Ghu
> that's an unwieldly name) yesterday and proceeded to take it apart. 
> This is relevant to the recent discussion about tablets and power
> consumption. For comparison, I have here an HP Pavilion dm1-4010us
> notebook with 11.6" 1336x768 screen and Fusion E-450 APU clocked at
> 1.65GHz.  The battery pack on it is rated at 55 Watt-hours and HP
> rates the whole kit as running "up to 9.5 hours" on battery power.
>
> iPad 2 has 25 Watt-hours of battery packs inside the case and is rated
> at 9-10 hours run time.  The The New iPad (by Ghu that's *still* an
> unwieldly name) has 42.5 Watt-hours of battery packs inside delivering
> the same 9-10 hours run time.  Nobody's publicly posted the TDP
> numbers yet but you can figure it's rather higher than iPad 2's based
> on the power consumption.
>
> It was suggested that these devices could ramp up their bus and CPU
> clocks when on mains power.  It's not "just" ramping up the clocks. 
> You need to cool it.  Even fanless Atom netbooks have open space for
> convection cooling.  There is no space inside iPads for airflow.  The
> metal case back is how iPads dissipate heat.  Apple doesn't even use
> screws because they take up too much space.  It's all glued together.
>
> That's the design philosophy for these things.  Doesn't matter who
> makes them, be it Apple or Motorola or Barnes & Noble or whoever. 
> More battery equals more run time equals better product.  They're not
> going to "waste" space for airflow when that space could be used for
> more battery.
Interesting. Some of the newer smartphones do not have replaceable
batteries also.  With all this demand for better batteries (eg. smaller,
lighter) I'm still not seeing any of the newer technologies coming to
market any time soon, such as carbon-nanotubes. Electric cars such as
the Volt (35 miles/charge), Leaf (90 miles/charge), Prius plugin (15
miles/charge) all laptops, smartphones, tablets suffer from the size and
weight of modern batteries as well as charge times.


IMHO, 9-10 ho0urs of battery time is reasonable for a laptop/tablet, but
the downtime to recharge can be significant.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
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