I am having a small challenge with this item. I know about the after blow that happens to my car. What happened last night was that the motor would start stop for less than a second and this continued without stopping. I left it to see if it would resolve itself but next morning battery was as dead as a dodo. First time this has happened. Jump started to car and it ran fine for the day. So far has not happened again. What could be the cause of this mysterious gremlin?

Any input will be appreciated.