Originally Posted by rico2surf
I have a sub-question based on this conversation, so hope that's not contrary to protocol. I have a '73 overlander 27', and we stay in the summer at a ranch without hookups, so we have a portable solar charger (Zamph?) to keep the battery charged (which works very well by the way). In the winter we keep it at an RV site on the coast (So. Oregon) with hookups. Question is, based on your comments above, should I disconnect the battery all winter while on Shore Power to save battery life?? We do not have any of the finer improvements of switching on or off; we have to physically disconnect the battery cables. If your suggestions is YES, disconnect, then is it necessary to disconnect both positive and negative cables?? Thanks so much !!
If your solar system has a good three stage converter and you have exposure to sunlight during the winter (you're not stored indoors), the solar system will do a much better job of keeping your batteries nicely topped off and maintained than will the inferior one stage converter/charger supplied with your Airstream.
Disconnecting your batteries entirely during the winter will tend to run them down. Charging through the one stage converter/charger with shore power will tend to overcharge (flood them.) So first check that you do have a three stage charger on your solar system. If it's an Airstream supplied system, you don't!
If neither of your chargers is three stage, you might consider disconnecting the batteries from the coach and buying a small solar panel trickle charger (about$50) and connect directly to your batteries. This is what we do with our tow vehicle and other vehicles that are only used seasonally, and it works very well.