On Mon, 24 Jul 2006 12:08:58 +0100, The Natural Philosopher wrote:

to recharge a 50KWh battery in say 5 minutes takes 600Kw. 2400A. at 250v.

Or a less unreasonable 800A per phase 3 phase, or 450A per phase at 440V

Not impossible, but not trivial either.

That's going to be forecourt technology, with a cable as thick as a
petrol/diesel filling hose!

However one could envisage the forecourt operators and vehicle designers
conspiring together to offer slower (30 - 60 minute, but still faster than
at-home) charging tied to supermarkets, cafes etc so that the punters form
a captive market for the retail offering while waiting for their vehicle
to charge up.

One would expect to pay more per kWH for the convenience (and the
operator's investment in the infrastructure) with the cheaper, slower
option of charging up at home from a more modestly rated home outlet, or
trickle/very-slow charging/topping up from a standard (13-15A-ish) mains
outlet. Of course if electric vehicles acheive a true mass-market there
will be lots of people for whom home charging is simply not an option
since they don't have off-road parking so forecourt charging will be the
only option.