Yesterday, for pre-flight and GPS programming, I hooked up an external battery to my 180D's auxiliary power receptacle via jumper cables and a Piper Plug & Jump. Happily, nothing smoked, fried or exploded when I turned on the master switch, and the gyros began to sing. My question is: how do I know that I'm really running off of external power rather than the internal battery? Would a multimeter show an amp load between the two poles of the Plug & Jump?
