The first generation Escape Hybrid (2005-08) had coolant lines running (there is a second radiator for this system) into the hybrid battery pack to manage heat. These coolant liines sometimes developed a crack. For extreme cold, these vehicles underwent a series of charges and discharges to warm the battery pack. In either the 09 or 10 model year, internal cabin air was utilized for this purpose. This change in system saved approximately 30lbs of weight. I'm curious on where the coolant lines run (internally or externally to the unibody) on the electric Focus.