trader_4 wrote
wrote

right, the answer is "it depends" as is the
answer to so many interesting questions..

if the battery is good but just needs to be charged,

He specifically said jumping a car to get it started.
To me, that doesn't imply charging it,

Yep, you actually are that terminal a ****wit.

it's when you've left the lights on in a parking lot

But in that case it works fine to use
the jumpers to charge that battery.

or have a battery that is going bad and use
someone else's car to jump start it right away.

Just one of the possibilitys.

a thin wire carrying a handful of Amps for a few
minutes will recharge it enough to start the car.

The problem there is that if you are really "jump starting"
it, to me that means connecting it to another car's battery/
alternator or similar capacity source.

But in some situations the problem is that the car that wont
start will turn the engine over fine but the voltage sags enough
so that the ignition cant supply a good enough spark to get
the engine to fire and all the car that is helping to start it
needs to do is supply enough voltage to get the engine
to actually fire and that doesnt require much current.

If you do that with a dead battery or mostly discharged
battery like you can expect to find and a thin wire, it's
going to melt the wire, because there is nothing to limit
the current to just a few amps.

Yes, but when you are using house wire, as the OP was
planning to do, its not going to be thin enough to melt.

The actual starting current comes from the recharged battery, not via the
cables.

but if the battery or connections are actually defective,
and the current to actually start the car needs to come
directly via the cables, heavy wire will be needed.