harry wrote:
On Feb 22, 11:16 am, Lee wrote:
On 22/02/2012 09:42, tony sayer wrote:

But there are still serious problems with implementing these the
main one is the primary power system. Batteries, unless someone
does invent one that is neigh on 100% efficient and has much
greater capacity and costs and weighs sod all, will always be their
great limitation.

There is another problem here, namely that if a much higher density
portable energy solution was developed it would have too much
potential to be "unsafe".
Whether deliberately or not.

There is other technology on the horizon.
http://en.wikipedia.org/wiki/Super_capacitor

Instant charging is possible.

The ultra battery:
http://www.csiro.au/science/Ultra-Battery