I have a 160w Go Power panel (specs below) on the roof of my toyhauler fed to a Blue Sky Sun Charger 30 PWM CC. 208ah battery bank (two Interstate GC2 in series). Built in Onan 4000W generator. No large inverter and no plans to add one (just a small 750w for running TV).Looking for good advice on adding a panel on the ground that I can point East in the morning and West in the afternoon. I don't want to spend the fortune Go Power wants for their portable kits.Most of our camping is boondocking. I would describe us as light energy users. All lights are led. The portable unit would be nice so we could boondock at campfire rings under the trees.Assuming we would wire Parallel. Not sure about diodes.Thanks for any advice!Solar cell type MonocrystallineOutput power160 WRated current9.14 ARated DC voltage17.5 VOpen-circuit voltage 21.0Module efficiency 17.8%Connectivity MC4 connectorsFrame type Silver anodized aluminum frameCertifications CEDimensions 58.3 x 26.5 x 1.38 in / 1482 x 674 x 35 mmWeight24.5 lbs / 11 kgWarranty25 years (module) / 5 years (controller)

As an alternative, what about buying another CC for the panel? I'm using a 20 amp PWM cheapie that I bought from eBay for $8. The advantage of having multiple CCs is that you don't need to worry about diodes, and adding/removing panels is easier.The high end RV solar installs in the past six months are putting each panel on its own CC (usually MPPT controllers), so it might be an idea.

Just get a panel that you can set out and enough wire to reach where the sun is. Your controller needs depends on how yours is hooked up now.If you can get wires to the array side of the controller from outside the rig, you can just add them to the array terminals now being used by the roof panels.Or you can run wires from those array terminals as a fixed installation to a place you can get at their panel ends and have Anderson connectors or whatever to bring your portable's wires to.Or if that is all too difficult, you can get a second controller on eBay for about $20 and rig that up near your batteries and bring your portable's wires to that controller's array side. ( It is fine to have two controllers on the same battery bank adding their amps--but make sure they are about the same voltage set points to get them to add their amps)I have a panel set outside and the wires that run out to it are ordinary jumper cables clamped clamp to clamp until they reach where the panel is. Or you can get wire. Some people use that wire that is for well pumps that you can get at low cost and in long lengths.The portable panel can travel on the bed or behind the sofa in the RV, whatever works.BTW you don't want to point the panel East or West for best results. If you never move it, point it South tilted up. Or point it to the middle of your open sky area if the sky is partially blocked off by trees or other trailers. If open sky all round and you only move it twice then SSE and SSW is the way to go.Aiming it at the sun early and late might seem better, but the sun is so low then, you don't get much anyway. Mid-day is where the money is.

Thanks guys. Good info. I cannot get wires easily to my charge controller. What's there was factory installed. I would probably get parallel connectors and then drop the cable for the portable panel down the refridgerator roof vent and put in a quick connect behind the fridge ground vent.Not sure the cheap Ebay CCs will put out the 15.3v I may need to keep the GC2 batteries fully charged but I'll check them out.

You could hook the portable panel's wires up to the roof and connect to the existing roof panel's wires up there, so they all share the wires going down to the array side of the existing controller. You could have wires from up there coming down to where you can get at them behind the fridge and just quick-connect to them.The panel on the side of the rig behind the fridge has slots in it you can pass wires through. For a time, I had a second solar controller in there behind the fridge out of the rain. I had the battery wires going down through a hole I drilled in the wooden platform the fridge sits on that is above the converter and DC panel/battery lugs in our trailer. The controller has to go on the battery in parallel with the converter onto those battery lugs. Do not have the converter charging through the solar controller from its array side. The controller behind the fridge took the array wires from the portable panel down from the roof if the portable was on the roof using the fridge vent, or if the panel was on the ground then I passed the array wires through the slots in the side vent cover.The lower cost eBay controllers only do 14.4 or thereabouts. You can get a Solar30 that will do 15v and perhaps will overshoot a bit like mine and Niner's does to get you that 15.3 They cost about $35.

Adding a portable panel to roof mounted panel | Good Sam Community

hammick
Explorer
Apr 10, 2015
Thanks guys. Good info. I cannot get wires easily to my charge controller. What's there was factory installed. I would probably get parallel connectors and then drop the cable for the portable panel down the refridgerator roof vent and put in a quick connect behind the fridge ground vent.

Not sure the cheap Ebay CCs will put out the 15.3v I may need to keep the GC2 batteries fully charged but I'll check them out.
4aSong
Explorer
Apr 10, 2015
Look into Renogy
BFL13
Explorer II
Apr 10, 2015
Just get a panel that you can set out and enough wire to reach where the sun is. Your controller needs depends on how yours is hooked up now.

If you can get wires to the array side of the controller from outside the rig, you can just add them to the array terminals now being used by the roof panels.

Or you can run wires from those array terminals as a fixed installation to a place you can get at their panel ends and have Anderson connectors or whatever to bring your portable's wires to.

Or if that is all too difficult, you can get a second controller on eBay for about $20 and rig that up near your batteries and bring your portable's wires to that controller's array side. ( It is fine to have two controllers on the same battery bank adding their amps--but make sure they are about the same voltage set points to get them to add their amps)

I have a panel set outside and the wires that run out to it are ordinary jumper cables clamped clamp to clamp until they reach where the panel is. Or you can get wire. Some people use that wire that is for well pumps that you can get at low cost and in long lengths.

The portable panel can travel on the bed or behind the sofa in the RV, whatever works.

BTW you don't want to point the panel East or West for best results. If you never move it, point it South tilted up. Or point it to the middle of your open sky area if the sky is partially blocked off by trees or other trailers. If open sky all round and you only move it twice then SSE and SSW is the way to go.

Aiming it at the sun early and late might seem better, but the sun is so low then, you don't get much anyway. Mid-day is where the money is.
mlts22
Explorer
Apr 10, 2015
As an alternative, what about buying another CC for the panel? I'm using a 20 amp PWM cheapie that I bought from eBay for $8. The advantage of having multiple CCs is that you don't need to worry about diodes, and adding/removing panels is easier.

The high end RV solar installs in the past six months are putting each panel on its own CC (usually MPPT controllers), so it might be an idea.

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Adding a portable panel to roof mounted panel

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