I have a 2008 Fleetwood Southwind 37c, I maintain the engine battery with an automatic charger. I would like to charge the coach batteries by plugging in to 20 amp service. 1) do I need to turn on the 2 switches or will the auto detect do it. 2) will the batteries charge like this ? We have a solar charger but during winter the coach is covered and that disables that feature. I have been starting the generator to charge, but it gets problem some when wind and snow are present. Thank-You in advance !