Large currents flowing in a length cable can be measured using the voltage drop along the cable. It eliminates the need for a bulky shunt or expensive magnetic measurement method. Accuracy is limited however because of the +0.39%/°C tempco (temperature coefficient) of copper.
Temperature sensors can facilitate compensation, but are point-measurement devices, the relevance of which is questionable over the length of a cable. Consider that a mere 2.5° error or difference from the cable temperature introduces 1% of error.
If at least 10mV is dropped at maximum current, you can readily measure it with modern zero drift amplifiers (auto-zero, chopper, etc.). They offer ultra-low offset performance that enables accurate sensing of the low full-scale voltage drops.
What remains is what to do about the tempco. The solution proposed in this Design Idea takes advantage of the fact that high current cables are made up of many fine strands. The example here will be based on AWG 4 cable with 1,050 strands of AWG 34 wire.