winch power lead

[trailertam]

I have a portable electric winch which fits on the towbar of my car. Power comes from the car battery via two cables and crocodile clips. The cable is not long enough to reach from ther car battery to the rear towbar. could I add extra length using cable from a set of jump leads and if so, how should I join the two - splice the wires together or use a two part plug similar to those on some lawnmowers.
Thanks

[scotman]

What power is the motor?

[trailertam]

Motor is 25 Amps, 280 Watts

[scotman]

Just to clarify the situation; the cables are permanently attached to the winch motor and connect to the battery by large 'crocodile' type clips. Is that correct?

[The Builder]

You wouldn't need anything as heavy as jump leads, tam. Domestic 2.5mm ring main cable could carry that load .......... 4mm to be really sure.
I would replace the whole cable with longer. Much better than joining or extending.

[AlBags]

Correct .. Heavy leads .. and leave the car ticking over while in use .. unless you trust the battery 100%. More than 5-10m use would prevent a start on a very cold diesel engine.