[Arm-netbook] flying squirrel conundrum

[Zooko Wilcox-O'Hearn]

On Mon, Nov 26, 2012 at 6:59 AM, jm <joem at martindale-electric.co.uk> wrote:
>>
>> 3200mAh battery    $6.00    EEMB    10000
>
> Charger costs missing????
>
> This may be off the beaten track in terms of marketing, but have you thought about using rechargeable AAA, AA or 18650 batteries?

I was going to suggest this same thing! My Newton Messagepad 2100 ran
on AA's, and they worked great.

If you already own a charger, then rechargeable AA's are probably
better for you than traditional lithium batteries. Consider: a single
modern high-capacity AA would have 2100 to 2700 mAh — comparable to
that 3200 mAh EEMB (especially after the latter degrades with time and
use) — would weigh the same (30 g), would be smaller than the EEMB,
and best of all it would be cheap and easy for the consumer to
replace.

The cheap high-capacity rechargeable AA's cost about $2.50/unit and
the fancy new ones (Sanyo XX Eneloop or PowerEx 2700 mAh) cost about
$3.50/unit.

You could carry extra batteries in your purse, no problem. The EEMB
battery, on the other hand, the end-user really cannot replace.

I would say that the right comparison is not between a brand-new
lithium battery and brand-new rechargeable AA's, but between the
laptop battery that people actually use and the rechargeable AA's that
people actually use. I'm pretty sure the latter have superior
capacity, because they are cheap and easy to replace. The former — the
laptop batteries that people actually use — are often worn out, and
are expensive or impossible to replace.

Case in point:

MAIN zompu:~$ cat /proc/acpi/battery/BAT0/info
present:                 yes
design capacity:         56000 mWh
last full capacity:      24430 mWh

I could replace it, at a cost of $129 before shipping:

http://store.apple.com/us/product/MA348LL/A/rechargeable-battery-15-inch-macbook-pro

Or buy a generic Chinese replacement for half that much and cross my
fingers. Instead, I'm just living with 44% capacity. I figure users of
the EEMB battery above would end up doing likewise, so the capacity of
the rechargeable AA might turn out to be greater than that of the
lithium in practice.

As far as marketing goes, maybe offering to run on AA's (at least as
an option?) would be good! It would provide something tangibly
*different* about this product.

Regards,

Zooko