Thanks a lot for the help..... The nato plug is always wired up to 2 x 12v batteries in series before plugging her into the nose of the a/c. Its weird cos it only happens about every 10th start. I am bush based so I have the key sent in every few days. The 2 x 12v batteries are getting tired, I only get 2-3 starts before needing a charge. The a/c battery is fine I just like to keep it good and assist with externals whenever I am at the bush base with the thought being that 2 x car batteries are cheaper to replace than a concord Jetranger battery.
Starts are perfect with a peak of of 720 and the start only taking 28 seconds....