Here's another thought you can use to determine a draw on the battery, good for those small draws that don't create a spark when you touch the cable to the post.
Put a volt meter between the cable end and the battery post. If there is a draw the meter will move, even if it is small, course if it's a big draw the meter will really move.
Just remember those old wind up clocks in the 60's ask for power once and awhile to wind the spring and would indicate a draw at that moment.
Dan
