Reason for weatherproof: set up suitcase panels with controller not in enclosed space and go sightseeing. It rains. Rain can happen when not expected.
Voltage drop CAN be mitigated by shorter distances and larger gauge wire. However, putting a suitcase panel in the sun may require longer distance with a wire gauge that is, ummm, more flexible. Hence my desire to put panels in series for higher voltage/lower current, and, put the solar controller close to the batteries rather than at the panels. A voltage drop from 36 volts/5 amps is much lower than voltage drop from 14 volts/10 amps. Especially when the dropped voltage from 36 volts is then converted to 14 volts.
