On 28/07/2014 13:46, Andy Wade wrote:
On 28/07/2014 11:48, Colin Stamp wrote:
What's the rated output of the charger? The cable from the garage to the
car shouldn't need to carry more than that.

Be careful, if we're talking about an ordinary single-phase
transformer-plus-bridge-rectifier type of charger (no smoothing of the
DC output) the RMS output current in the cable will be significantly
more than the mean DC current, due to the peaky waveform.

I'd advise rating the cable at least a factor of two above the rated
mean DC output, to play safe.

That's a bit further than I'd go - I'm guessing the number on the front
of that type of charger will be measured by whatever scheme makes it
highest, to the point of outright fraud. Still, as you say, better safe
than sorry.

Voltage drop considerations may dictate
that an more in any case.

Indeed. Particularly if it's an "Intelligent" charger, voltage drop will
be critical.

On the other hand, it could be a "charger" like this...

https://www.youtube.com/watch?v=-0RxmHgOVwc

In which case, you could probably use a mile of bell wire ;o)

Cheers,

Colin.