Not enough???

ericcjackericcjack Registered Users, Users Awaiting Email Confirmation Posts: 1
I have an RV that I'm trying to make self sustainable while camping.  The RV has the RV-30 DE Charge Controller.

I have (3) solar panels wired parallel.   All purchased on AMAZON (links provided):
(2) RICH SOLAR 200 Watt 12 Volt Moncrystalline Solar Panel   9.8 amp power
(1) Xantrex 780-0160-02 Solar Panel Expansion Kit - 160W, Rigid  8.3 amp power

Unfortunately I had not found the article Mixing solar panels – Dos and Don’ts before I purchased them.  I'm finding that on optimum days I'm only able to occasionally 19 AMPS with an average of 15 AMPS on the controller.  Could anyone advise me why I'm only averaging 15 AMPS and how I could increase the AMPS.  With only 15 amps of charge, during a typical sunny day, I'm only able to charge the house batteries 5% (I lose 15% at night).   I was hoping to be getting at least 24 AMPS.  HELP!   

Eric Jackson
Rensselaer, IN


  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Welcome to the forum @ericcjack

    As long as the voltages for each panel are close, within 10% it is fine to parrallel differing wattage ratings, unfortunately the link to the 160W has no mention of voltage , VOC and VMP, can you provide this information? 

    Although the theoretical combined current would be 27.9A in perfect test conditions at 25°C, the real world output would be somewhere in the 75-80% or 21-22.5 A range because the sun will increase the surface temperature above the test value of 25°C. To attain the maximum current the alignment to the sun must be perfect, anything else will reduce output, for example if horizontal which is common on RV's, the sun will never be directly overhead outside the tropics, 23.5 ° north or south of the equator.

    Being your latitude is 41°N some tilt will be required at all times of the year as well as being oriented towards the south, southeast or southwest or any where between to obtain maximum output available, this link will allow you to choose the best angle and orientation. 

    This is a brief simplified explanation.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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