On Sun, 08 Jun 2008 13:23:23 +0100, Andy Wade wrote:

Well, whatever figure you choose, someone will want more. 30 A was just
my guess at a reasonable limit and it's only about 400 watts. Enough to
run small mains appliances through an inverter,

Plenty of 12v microwaves and TVs about. Check the truckers web sites...

for a one-cup immersion heater for brewing up,

I have a 12v kettle 2 mugs capacity takes about 20mins to boil. Pulls a
good 10A and the cable gets warm...

or for 12 V power tools such as those little compressors,

Got a "heavy duty" compressor as pumping up one of the tyres from 10psi
killed the previous ordinary one. This one is continusly rated, fan cooled
motor, doesn't have a rating but probably no more than 10A if that.

electric winches, and so on.

Ah a decent whinch takes far more than 30A...

These days you could have a current limit set under software control,
like USB.

KISS is better I feel. There has to be "smarts" in the kit and the car.
The current 10A is enough but a smaller better connector really is needed.

--
Cheers
Dave.