Don't know what year the Escape hybrid was....but I towed a 2013 Ford Cmax many thousands of miles behind my motorhome. The HV battery probably isn't dead.....It will be the LV/12 volt battery going dead. Common issue back then. Fix was to run a power lead through the harness from the starting batteries on the coach into the Cmax to it's 12v battery. There is a spare circuit on most 7 pin connections. Never had an issue again. Before that I carried a small lithium jump start pack, just a quick touch to the 12v battery and the engine would start right up. Engine starts off HV system, but without 12v to tell the computer what to do it is dead.