have your battery company replace the cables, if ONLY 1 cable is getting hot. have your battery checked out for "voltage drop under load".
lower voltage = higher amperage = (same wattage to do the work) but more heat. since electric power is a circuit, the flow on both cables is equal, if only 1 is getting hot, then that one (most likely) has broken down inside the insulation.
also check the connector to the battery (all 3 halves, truck, battery and charger) charger half may have a weak spring or cracked case causing poor connection at the charger, causing poor connection on the truck and battery too.