Has anyone had an issue where your roadster will not charge? I plugged it in and it started to charge, and i went out of town for a couple of days and peeked in at the charge and the battery was a little more than half charged. The screen said plug the cable in, and i unplugged it and re plugged it and it still said the message. The color wont change to blue either to warm up the battery its like its not picking up the cable. Any suggestions?