I recommend checking a connection between a wire and an alligator. Mine were just clamped to the naked wire, unsoldered. After soldering it the resistance of red+black in series was 1.3Ω (so 0.75Ω/m). 5V 3A and it becomes warm. At medium-power application these wires are basically a pair of fuses that may set your workbench on fire. Be careful. For small currents (<1A) they are ok. Also they are NOT suitable as a replacement of multimeter probes due to high resistance. Even after soldering.