G'day all. I have just purchased a 250w folding solar panel kit and on the XTM regulator there is a Digital tube and a key. I have searched the net and found reference to it but do not understand anything about it. Could you guy's explain to me what it is for , in laymen's terms and how do I set it ( on/off)???? When I looked at the digital tube it was on 8 . There is only one on/off switch which I have turned off. One other question is can I charge 2 batteries with this set up. I use a desk top PC, not moby and not always near the PC to reply . Thank you all.