This is a “Do It Yourself” 600 watt solar panel system with a roof mounted junction box on a 27 foot RV travel trailer. This is adequate to charge about 300AH of 12V batteries.
Parts Required
- 6ea 12V 36cell 100W panels or equivalent similar panels
- An exterior junction box with 2 bus bars
- A 40 Amp PWM* charge controller, *Pulse Width Modulated Switching Regulator
- Hardware, brackets wiring and connectors
Inside the trailer is a 40A PWM MOSFET charge controller that is wired in parrallel with the 55A shore power converter, so either one can charge the batteries. I tried 3 different controllers but ended up with a home made controller. All panels are wired with 10GA to the J-box. Each panel is 12-18V and has 36 cells. All the panels are wired in parallel at the bus bars in the J-box. It has 6GA from the roof box down to the PWM controller. The wires are routed down the existing refrigerator vent. Internal wiring from battery to converter, and to other loads I use all 4AWG cable.
On a good day it puts out 35-38A at 14.6V to the battery. All the panels are mounted with “Z-Brackets” to the roof and I use stainless steel self tapping bolts and of course plenty of sealer around the bolts. Bruce McCaskie N6THN
Here’s the install
