Strobl-Solar: questions about panels, wiring, and switching

Assuming current runs from panels to a charge controller to a battery switching mechanism (rotary switch?) to a selected battery.

Most "full monty" panels now draw +/- 2 amps/hour. Normal setups use 2 @ 7.5 watt panels. Considering time in sunlight is probably twice as long as "flight time" can a 2 panel rig (which generates less than one amp) normally keep you from charging?

Or, would you recommend a four panel rig generating 30 watts?

Is it usual to have a current flow off/on switch or does current flow to a battery at all times?

Is it usual to route all current to one battery at a time?

Where is the controller normally located?

Does anyone have the manufacture/model number of the factory rotary selector switch?

Thanks for your response.