Community Forums

Banner Elk · 10-08-2017, 04:33 AM

What happens when you increase the solar panel wattage from 20 watts to 150 watts? Is there any danger to existing equipment and will that make the house batteries last longer? We boondock a lot and need the batteries to last at least 8 hours. Also does anyone know how to tell if the solar panel is working on a 2011 fleetwood discovery? The owners manual says there is a light on the AC that tells you they are working, but I can't find that light. Batteries are 2 years old.

twinboat · 10-08-2017, 06:34 AM

20 watts of solar is just about a joke. Probably just enough to keep a good battery from running down in storage.

If you upgrade to 150 watts, you will need a controller and possibly have to run new larger wires from the roof to the controller and then on to the battery compartment.

Using a 150 watt panel and controller should produce about 60 AH a day.

That would be about equal to running a 12 amp battery charger 5 1/2 hours a day, if sunny. Another way to compare is it will replace about 1 1/2 hours of generator time, If you have a 50 amp converter.

It's less then a gallon of gas in the generator, but it is quiet.

Stan&Jacquie · 10-08-2017, 06:45 AM

Quote:

Originally Posted by twinboat

20 watts of solar is just about a joke. Probably just enough to keep a good battery from running down in storage.

If you upgrade to 150 watts, you will need a controller and possibly have to run new larger wires from the roof to the controller and then on to the battery compartment.

Using a 150 watt panel and controller should produce about 60 AH a day.

That would be about equal to running a 12 amp battery charger 5 1/2 hours a day, if sunny. Another way to compare is it will replace about 1 1/2 hours of generator time, If you have a 50 amp converter.

It's less then a gallon of gas in the generator, but it is quiet.

You need to figure out how many Ampere hours your coach uses in a day. Solar panels are rated in Watts and also amps. Let's say a panel produces 6 A of power in bright sun . If you get six hours of bright sun in a day than that panel will add 36 amp hours of power to your battery by the end of those six hours. However if your RV consumes 200 amp hours of power in a 24 hour timeframe then you would need at least six of those panels to replace the electricity your batteries lost in a day. This example of course assumes bright sun for the full six hours. It would be wise to add an extra panel to account for cloudy conditions. Get the idea?

Dutch Star Don · 10-08-2017, 11:32 AM

"Banner Elk".......Fleetwood, for many years, added a small solar panel on top of the A/C shroud. It's ONLY purpose was to help maintain a charge on the engine start batteries while in storage. You can forget about adding or changing anything on the that small panel. It's a stand alone unit and not upgradable.

"twinboat" gave you good info on solar. Keep in mind that everyone has different solar uses. Some park in the desert through the winter months and require a LOT of solar to keep from running their generator all the time. Others, stay exclusively at full hookup RV parks and really don't need solar. We're in between the two. We have a residential refer and occasionally boondock, so we have a limited amount of solar 300 watts.

With all that said, you have to look at YOUR needs. Sometimes, it's cheaper to just add a couple of batteries versus $$$ in solar panels.

Banner Elk · 10-09-2017, 03:41 AM

I only used 20 watts as an example because I don't know what the wattage is on the panel. I have no paper work. That being said,you are saying if I have a 300 watt and want to go to maybe a 1000 watt new wire and control will have to be installed...right?
Where do you look for the controller?

twinboat · 10-09-2017, 04:01 AM

Quote:

Originally Posted by Banner Elk

That being said,you are saying if I have a 300 watt and want to go to maybe a 1000 watt new wire and control will have to be installed...right?
Where do you look for the controller?

Not necessarily. A 300 Watt system may have heavy enough gauge wire to add some capacity, if you add it in series. Then only the wire from the controller to the battery would need upgrading.

There are many ways to build a solar charging system and lots of design work before ordering what you need.

There are lots of venders out there and many sell kits with the correct components. Go to AM Solar and do some research. You can also look on Amazon for some of their components or kits.

Stan&Jacquie · 10-09-2017, 08:41 AM

Quote:

Originally Posted by twinboat

Not necessarily. A 300 Watt system may have heavy enough gauge wire to add some capacity, if you add it in series. Then only the wire from the controller to the battery would need upgrading.

There are many ways to build a solar charging system and lots of design work before ordering what you need.

There are lots of venders out there and many sell kits with the correct components. Go to AM Solar and do some research. You can also look on Amazon for some of their components or kits.

Good advice from twin boat. If you are on the East Coast I would recommend alt E in New England. You should call a vendor and have tech-support talk you through a system designed to suit your needs. They will even suggest what specific parts you may need to purchase. Your needs might be satisfied by a complete kit they already have put together which would save you some money. Do it right and you won't regret it. It doesn't pay to skip or cut corners. Good luck!

Dutch Star Don · 10-09-2017, 05:19 PM

"Banner Elk".....Unless someone else installed a large solar panel and wiring, your coach more than likely didn't come with it. It hasn't been until the last few years that manufacturers have been adding solar prep. Even if yours doesn't have solar prep, it's not that hard to add, especially on coaches that still have a refer vent on the roof. Just run the wiring down the vent to the battery bay.

Solar can get confusing and when you ask someone about it, they usually start rattling off terms and components that really don't help a newbie much.

I didn't know much about solar and was only interested in about 300 watts. Luckily, I have a solar panel company nearby that sells panels directly to the public out their back door. I was able to buy three 100 watt panels, wiring quick connects and a quality Xantrex controller for about $450.00.

astrnmrtom · 10-13-2017, 06:20 PM

It's really hard to tell what kind of panel you have on your rig. The little square ones mounted on the top of an ac unit are usually under 25 watts and just provide a tiny trickle charge on the order of an amp or two to the batteries to counteract the normal loss from them sitting. Moving up to a large panel will require a controller and new wiring as mentioned above.

When you say you need your batteries to last 8 hours it's important to know what this means. If you are just running your water pump and a few lights this isn't a problem, but if you are running an inverter and using it to run a coffee pot, microwave or other high draw items that's a whole different matter. Think of your batteries as a bucket of water. The faster you drain the bucket the faster you have to put water back into it to keep it from going empty. A 1/4" trickle of water won't keep up with a 1" hole in the bottom.

It would be helpful if you could be more specific. What kind of things do you want to do with your batteries in those 8 hours?

Adding solar isn't difficult if you are handy.

Flyin4Fun · 10-13-2017, 08:46 PM

Dutch Star Don, are you willing to share the contact info for that company? I have a 2004 Monaco Dynasty, 2000 watt Xantrex system that I believe is solar ready. I'm not certain if there is another component necessary between the panels and the inverter... I am in the process of determining what was installed at the manufacturer, but I am under the impression that all it needs is panels. The line item on the sales order says: “Solar Option, W/O Panels”.

I would like to add 300 to 450 watts of solar panels. I am a newbie at solar, but understand electricity quite well.

Crasher · 10-14-2017, 08:33 AM

You need to talk to a professional solar tech. Tell him what your total amp draw is and where and when you will be boondocking most of the time. That will tell him what size system you will need. The angle of the sun to where you will be can play a big roll in sizing the system. I have 640 watts of panel and will get about 36 amps of charge from 10am to 2 or 3pm. It tapers off before and after those times. This is in sunny AZ in the winter. Ours is an all electric coach with 900 amps of battery storage. I wanted to add more solar, but instead, bought a 2KW Honda generator that will run for eight hours on a gallon of gas. I use it when needed. Solar can be a good investment if it is done with adequate planning and fits your coaches demand.