Solar umbilicals?

[rabbit]

I've decided not to acquire a generator based on advice received here. Have 80watt Evergreen solar panel on the way. It has a perfect footprint for storage under the bed in the Burro and I want to avoid a roof mount so everything should be simple except that I really can't find a schematic for hookup and have no experience to draw on. I have tentatively settled on an inexpensive, no frills Morningstar Sunguard 4.5AMP controller which appears to have cables to battery and to junction box on panel. I think I am competent to build an adequate "signboard" support for deploying the panel on the ground and a protective case but have been unable to determine what additional extension cable? with what connectors? of what length? I will need to give the panel a bit of leash room for placement near the trailer. What works? What's customary? What did you do? TIA

jack

[Byron Kinnaman]

The controller should have a schematic with it. It's really not difficult. I installed Anderson Power Pole connectors on the cable from the controller battery connection, and added a cable to battery with like connector on it. Now it's a simple matter of plugging in the solar panel to the battery. The controller is mounted on the "signboard" frame, so there's a short cable from the panel to the controller. All pieces are marked with a "+" and a "-". Two wires from the panel to the controller, two wires from the controller to the battery. Ignore the "load" terminals on the controller. There should also be a diode in series with the "+" lead at the panel. A solar panel will draw current when it's dark.

To carry the panel I build a 2x4 height platform that rides in the bed of my truck. The panel slides under the platform with the tail gate holding it in. I do have a canopy and a bedrug so it's well protected.

Hope this helps. If not I can send pictures, but that will have to wait until the week-end. My truck's in the shop.


As for length of wire, I use a 12 awg wire that's about 15' long, and have a couple of extensions that are about 10' long. They all have Anderson Power Pole connectors on them so I go out to about 35' if needed.

[Ron F]

Jack, Check out Gina's solar connection. It's a very simple solution and tailor made for free-standing panels. Here's the link: http://www.fiberglassrv.com/forums/f...ing-38147.html .
Ron

[Carol H]

I did a simple system for my panel. PVC pipe holder that comes apart for easy storage and a water proof box attached to the battery box that holds the controller which is always connected to the battery. Drilled a small hole in the bottom of the box to fit the battery leads through and then caulked around the hole. All I have to do is open the box up a bit at the bootom to get the plug that attaches directly to the panel & to give the controller some air while its working - the panel came with a fairly long lead - long enough to move the panel around in what ever position the sun is in. Did not need to buy any other wiring. Everything I needed came with the panel and the controller. simple.


Add'n: I made a foam storage holder which I added some plastic to the outside and put in a nylon cover over it all to store the panel and PVC holder when not in use. Added a 4 eyes through the outside bathroom wall and some bungee cords to hold the panel up and out of the way when not in use.

[Rick G]

Originally Posted by rabbit

I've decided not to acquire a generator based on advice received here. Have 80watt Evergreen solar panel on the way. It has a perfect footprint for storage under the bed in the Burro and I want to avoid a roof mount so everything should be simple except that I really can't find a schematic for hookup and have no experience to draw on. I have tentatively settled on an inexpensive, no frills Morningstar Sunguard 4.5AMP controller which appears to have cables to battery and to junction box on panel. I think I am competent to build an adequate "signboard" support for deploying the panel on the ground and a protective case but have been unable to determine what additional extension cable? with what connectors? of what length? I will need to give the panel a bit of leash room for placement near the trailer. What works? What's customary? What did you do? TIA

jack

Is your 4.5 Amp controller big enough for the panel? If you get 80 watts from the solar panel, at 12V that would be 6.7 Amps, beyond your controller current limit. If your panel and controller were higher voltage, 18 or 24 volts, and it could convert down to 12V at 4.5 amps, that is still only 54 watts maximum going to the battery. Much of your solar generated power could be wasted, and the controller could be stressed if it often runs at its maximum current.

Wiring should be OK, as even 16 gauge outdoor extension cords can handle 15 amps of current at whatever voltage, and will handle 4.5 amps (or 8) with no problem. I have used standard (waterproof) outdoor extension cords in the past with good results, cutting off the ends and using a connector of choice for the application. However, perhaps you should consider a higher-current controller.


Regards,
Rick G.

[Byron Kinnaman]

Originally Posted by Rick G

Is your 4.5 Amp controller big enough for the panel? If you get 80 watts from the solar panel, at 12V that would be 6.7 Amps, beyond your controller current limit. If your panel and controller were higher voltage, 18 or 24 volts, and it could convert down to 12V at 4.5 amps, that is still only 54 watts maximum going to the battery. Much of your solar generated power could be wasted, and the controller could be stressed if it often runs at its maximum current.

Wiring should be OK, as even 16 gauge outdoor extension cords can handle 15 amps of current at whatever voltage, and will handle 4.5 amps (or 8) with no problem. I have used standard (waterproof) outdoor extension cords in the past with good results, cutting off the ends and using a connector of choice for the application. However, perhaps you should consider a higher-current controller.


Regards,
Rick G.

The controller controls how much current is sent to the battery for charging based on how much of a charge there is already on the battery. That's the reason you need a controller to prevent over charging.
The rating of the charge controller is how much of a load you can put through the controller. In my case I don't use the load output of the controller so the size can be as small as possible, thus cheaper.

Mine is a 6amp since that was the smallest I could find at the time. The most current I've seen charging the battery is 4.2 amps. No matter what the solar panel is capable of the system will only use as much as needed. Nothing bad happens to the rest. Think of a battery the capable of producing 300 amps but you're only using 1 amp, nothing is going to be hurt, damage, heated etc.

[Byron Kinnaman]

Originally Posted by Carol H

I did a simple system for my panel. PVC pipe holder that comes apart for easy storage and a water proof box attached to the battery box that holds the controller which is always connected to the battery. Drilled a small hole in the bottom of the box to fit the battery leads through and then caulked around the hole. All I have to do is open the box up a bit at the bootom to get the plug that attaches directly to the panel & to give the controller some air while its working - the panel came with a fairly long lead - long enough to move the panel around in what ever position the sun is in. Did not need to buy any other wiring. Everything I needed came with the panel and the controller. simple.


Add'n: I made a foam storage holder which I added some plastic to the outside and put in a nylon cover over it all to store the panel and PVC holder when not in use. Added a 4 eyes through the outside bathroom wall and some bungee cords to hold the panel up and out of the way when not in use.

I thought about that, (controller in the battery box), but I carry a second battery in the back of the truck. Also I can connect the solar panel to the tow vehicle's battery and charge it if I need to. Therefore the controller is mounted on the solar panel frame.
Just another thought and reasons for me doing what I did.

[rabbit]

Yrs. ago, I was introduced to the hydrodynamic analogies for the mysteries of electricity: "size of the pipe, speed of flow". It didn't stop between ears LOL. Thanks for the advice.

jack

[Joy A]

I got elaborate with my solar connections.

I mounted the controller (it's digital) inside the trailer on the electrical compartment wall and ran wires to the battery. Then I ran wires from the controller to an outlet mounted through the outside wall of the trailer. I extended the wire from the panel and added a plug.

So my solar panel simply plugs into the side of the trailer. I generally place the panel on the top of the trailer but can place just about anywhere I choose.