I am going to put another battery in my boat but I need to get this thing dumbed down for me a little. I see a lot of you guys use the Blue Sea add a battery kit. Does this kit allow you to set the switch to either 1 or 2 and leave it alone and the alt will charge which ever one needs to be charged? I really do not want to flip switches all day. I want something that I do not have to mess with at all. Also what do you guys think about an onboard charger? My boat will be on a lift at the lake and I will use it on the weekends primarily. Can I just get portable one and use it as needed? Thanks guys