New to site, long time fuel flyer newb to electric. Couple of questions. I have the mini Funtana by e-flite with 480 motor, 40a speed control with bec. Question, there is a second lead off the thunder power battery that I dont know what it is too. There is a + and - the second one has a small plug. Second Q. do I need to put an on/off switch on an electric system? if so how do I wire it?

Thanks in advance.