[sandworm101]

Maybe, but the dead battery is still in the circuit. So a tiny wire won't provide enough current to raise the voltage enough across the entire circuit. (I assume that it requires something akin to a the solenoid of a IC car.) You don't need the cranking amps, but you will still need something thicker than a USB cable.

[function_seven]

Ah, good point. I guess it matters whether your battery is drained, or dead. Sometimes the battery just doesn't have the juice to turn the starter (you hear the clicking of the solenoid when trying to start, but no cranking). Other times it's so depleted that an external current supply will be sucked up by the thirsty battery.