In message , Andrew Mawson
writes
"Tim Lamb" wrote in message
.. .

In message , Clive Arthur
writes
On 20/01/2018 17:45, Tim Lamb wrote:
Smart meters will be able to identify electric cars and charge the
missing fuel duty, VAT and climate change levy (from the coal-
fired powerstation) to your leccy bill. Ha Ha

No they won't.
Hmm.. something might. Assuming full wave rectification, the
battery will only draw current when the supply voltage exceeds that
of the battery. I doubt it would take much electronics to spot that.

That could work with a very old-fashioned car battery charger, but an
EV charger will be a sophisticated switch-mode unit with power factor
correction.
I'm a very long way out of touch Clive and my maths have always been
suspect. However, my assumption is, for a domestic single phase
supply, there will be a number of milliseconds where the voltage is
insufficient to provide a charge.

Now you can store energy in a capacitor or an inductor but these would
need to be high capacity in view of the charge current needed.

I doubt much of this current draw is going to be sinusoidal so
probably identifiable with respect to conventional domestic loads.


And how could it possibly differentiate between an electric vehicle
used on the public road, and one used (for instance) at a private golf
links or an electric off road farm vehicle, fork lift etc ... it
couldn't
No:-)
Maybe they would have access to DVLA records? Now I am being silly.

--
Tim Lamb