I'm at my in-laws and the standard wall charger using a 5-15 adapter (for standard house plug). When I plug it into the wall I get green for 1 second and then 4 red blinks on my charger. The 4 red blinks continue. (not plugged into car) I've tried on all of the plugs in the garage and get the same thing... (I'm aware that the 4 red blinks means ground, but it doing it on every plug in the house confuses me...?) Any advice?