I'm about to fit a 120W solar system to my MH and also want to fit a battery charge manager (like the BCM12) to keep my cab battery topped up. I believe these charge managers switch over at something like 13.6 volts. My solar controller (Tracer MPPT) bulk charges at up to 14.2 volts (not quite sure of the exact figure as don't have the info in front of me). I believe that charging up to this voltage then going back to a maintenance voltage is better for the battery. This means that my leisure battery will never get a full charge as the BCM12 will switch over to the cab battery. Does this mean that I can't use a charge manager with my solar controller? How do I keep my cab battery topped up then? No doubt others have done this.