At 10:25 AM 07/10/2010, you wrote:
>   As per subject. Just wondering if anyone's got more clues than I've
>managed to find so far.
>
>Thanks
>Matt

One word: Electrochemistry.

Rechargeable alkaline cells are ~1.5V, lead-acid cells are a bit over
2V, and Lithium ion cells are more like 3.6V. But each battery chemistry
has its own advantages and disadvantages as far as energy density
(volumetric or mass), recharge time (and complexity of charge
algorithm), lifetime, tendency to self-immolate, self-discharge rate,
etc.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the rewar=
d"
speff@interlog.com             Info for manufacturers: http://www.trexon.co=
m
Embedded software/hardware/analog  Info for designers:  http://www.speff.co=
m



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