"Frnak McKenney" wrote in
message ...

Has anyone here used -- or even seen -- a pair of "cigarette
lighter"
plugs wired together and sold as a "jumper cable"? The concept
certainly
has appeal -- battery-to-battery jumper cables are heavy, bulky, and
stiff -- but how would it handle the (say) 100A "cranking current"
needed
to get an automobile with a dead battery started? Ian's "8-10A",
which is
an order of magnitude lower, seems like a good working figure for
that
kind of connection, and with that limitation even a superconducting
cable
wouldn't be enough.

Or have I missed something?


Frank McKenney

I have one to connect the lighter sockets I added to my tractor and
battery charger. I have to be careful with it to avoid blowing the
outlet fuse by shorting the battery to the exposed sheet metal. Once
it blew from the current surge into the unpowered charger's output
capacitor.

I doubt the fuses in a car would survive the current from a good
battery to one too dead to start the engine.

The plug-to-plug jumpers could be cut and rejoined with Andersons to
get two good plugs to borrow for other uses, such as if the plug a
device comes with is bad.

-jsw