Solar install on a Trailer, newbie questions

pauldub wrote:
it's far from optimum. You want to minimize the voltage drop between the controller and the battery.

Define "far".

If the controller has remote voltage sensing, it's mice nuts. Which it is anyway, since you only get significant voltage drop with high current so it doesn't keep the battery from getting fully charged. It can cost a few percent in efficiency. But if a few percent is critical, one should just add another panel and be done with it - don't worry, be happy.

And, if charging while there's a power draw, sending current to the battery then back to the converter/distribution is also a loss. The wire between the solar controller and the battery would need to be significantly larger than the stock wire from converter to battery for there to be any advantage even with no power draw during charging.

A lot of the common knowledge about solar is based on the days of $5+/watt panels, where spending $50 in time and material for bigger wire provided a meaningful return on investment. Things have changed, and other than space limitations, putting another panel up is a much better deal these days, in addition to providing more capacity for overcast days, etc.