I almost always keep our 75D plugged into the Wall Connector any time the car is in the garage. However when I left the car I plugged one night, there was a loss of range of almost 30 miles. The temperature had dropped to below 30 at night but this big a drop in range seems excessive. Is this to be expected ? I'm also wondering if the heat in the car comes on at night for pre-conditioning, leading to this loss. Any ideas ? Thanks !