How feasible would it be to add a modular, say 50kWh battery to an EV via the trailer hitch that could be used while towing and then returned to the rental shop when done?

Obviously the HV wires would be a significant concern, so the cable would need to be well protected. What other considerations would there be?

Maybe the battery could sit in the bed of the pickup and again, would need to be well protected and secured.

Has anybody ever heard of something like this in other applications? 2 large Lithium Ion batteries connected via a HV cable?