Using "wire gauge" as my search on the Internet, I found three charts indicating amp limits for 12/14/16 AWG wires; but, feel that voltage applied and length of wire should be taken into account. The info from the three charts follows:
------------"A" "B" "C"
16 AWG @ 13A 15A 22A
14 AWG @ 17A 25A 32A
12 AWG @ 23A 40A 41A
Hoping that chart "C" is more correct than the others...he, he...
By the way, how many amps can four NIMH cells output anyway?