2oldman wrote:
Bobbo wrote:
Reason for weatherproof: set up suitcase panels with controller not in enclosed space and go sightseeing. It rains. Rain can happen when not expected.... put the solar controller close to the batteries rather than at the panels.
This still isn't making any sense to me. If the controller is close to batteries, wouldn't it be inside?
RANT ON
No. My battery box sits on the tongue and has no space inside. My TT has no way for me to put the controller for a suitcase panel inside. This is not rocket science. The controller will be out in the weather. The weatherproof box suggestion above is the only actual solution suggested. And it is a good one, probably the one I will use. Everyone else seems to be trying to explain why my problem can't exist.
Let me make this simple. A suitcase panel has a weatherproof PWM controller attached. I want to replace that PWM controller with a weatherproof MPPT controller. That is the complete, entire, problem. Where I am going to place that controller has gotten everyone sidetracked.
The reason I am going to place the controller near the batteries is explained below. According to a voltage drop calculator online:
Using 30 feet of 10g wire, a 200 watt (parallel) panel's PWM controller, on the panel, sends 14.4v and 12 amps out to the battery. You have 0.86v drop, so the battery gets 13.54v.
Using 30 feet of 10g wire, a 200 watt (series) panel sends 36v and 6 amps out to the MPPT controller at the battery box. You have 0.43v drop, so the MPPT controller sees 35.57v, and sends 14.4v to the battery, and the battery GETS 14.4v.
If I seem peeved, I am tired of reading that I need to put the controller inside. I can't. That is not a helpful suggestion.
RANT OFF
BTW, CA Traveler and agesilaus, you have been very helpful. Thank you.
