Add more solar panels, or not?

[David M]

Originally Posted by weirdstuff

David, thank you so much! That looks great. And all the info there about brand, and cost...super helpful.



Do I understand correctly, the following? When there's no sun, the house battery will still deplete (cloudy day, or evening/night time). And that the benefit of having more solar is that, when the sun comes back out, that it will charge the house battery more quickly. So I don't get more power, I just will get the ability to charge back up more quickly. Right?

That's correct. I use my AI as a daily driver so I leave the fridge running 24/7. The factory 50w panel did not keep up with the demand, but the 200w panels keeps up with the fridge, all the parasitic draws, and keeps the batteries charged. Of course when it's overcast, the panels aren't nearly as effective, but they still put out almost as much as the 50w panel did on a sunny day. Fortunately, we haven't had many cloudy days in So Cal so I rarely have to plug into shore power, and the only time I run the generator is to keep it exercised. I might add a 3rd panel if I lived in Oregon, but it's rained on my Interstate maybe 4 times since I got it last April.

[switz]

Here are some solar panel sizes from AM Solar. We used eight of the GS100 panels and they fit between the Air Conditioners and the edge of our trailer roof and might work as well on the vans. The length includes the mounting brackets.

These High Efficiency Solar Panels turn Sunlight into Power for your RV Lifestyle

GS100 100 watts 20.70" x 44.175" 14.5 pounds

GS135 135 watts 21.02" x 60.500" 20.5 pounds

GO160 160 watts 26.00" x 61.375" 25.5 pounds

Note that they have a flexible solar panel unit in development.

[lewster]

Just as a side note; I use the GS series exclusively on Airstreams as the narrow profile works best with the matching narrow curved dude profile if the roof.

I also use special talked feet on the outside edge to allow for a flat installation. And BTW, those dimensions are with mounting feet attached.

[Boxster1971]

The link below is to an old article on an Airstream Life Blog. It contains great practical information on why solar panels are a good solution.

http://airstreamlife.com/maze/2010/0...ry-of-the-sun/

[lewster]

A very nice basic blog about battery charging and the benefits of solar.

To take it a bit further, if your batteries are depleted to, say, 50% depth of discharge (DoD)....they will read about 12.2VDC. Assuming that you have a quality multi-stage charging system like a Magnum inverter or good solar charge controller, here is what happens with your charging current.

Let's say that the capacity of your charger is 50 amps, and your battery bank is 300 amp/hours of Lifeline AGMs. At 50% DoD, you need 150 amp/hours of current to be provided to the batteries to bring them back to 100% charge. The charging system starts in bulk charge, where the current and voltage both increase up to the maximum capacity of the charger, which in our example is 50 amps and 14.2 VDC (assuming the temperature at the batteries is 77ºF).

Once this level is reached, the charger switches to absorption charge ( I like to call it taper charge, and you see why shortly). The voltage and amperage stay at the maximum level until the battery starts filling, and then an interesting thing happens: the voltage stays at 14.2 VDC but the charging amperage begins to drop or taper as the battery continues to fill. the charge amperage will continue to drop until the battery is almost full.

At this point, the charger goes into float charge, where the voltage now drops to the specified amount required by the battery manufacturer, which in our example is 13.2VDC and the current also drops to a minimal amount (usually between 1-5 amps). This charge phase keeps the batteries full and happy at between 12.8 and 13.2 VDC.

This is a very simplified version of 3-stage charging. There are actually 4 and 5 stage charging systems available (Magnum uses these) but this a basic example. All of the specifics are available as to required voltage per cell, actual charging times, etc. which are wholly dependent on the type and size of your battery bank and the age and condition of said battery bank.

Any questions?

[K9CarCrate]

I think Ohio may not be the best place to get advice on maximizing with solar panels...

[weirdstuff]

Originally Posted by K9CarCrate

I think Ohio may not be the best place to get advice on maximizing with solar panels...Attachment 210806

Is that your rig? If so, more info please on what you've got going on and where you got it done!

Do you think AS Ohio just doesn't have lots of knowledge about solar in particular? Or is there another reason?

[Skater]

I'm going to say: Do it. We love our solar system.

We just got back from a trip where we boondocked from Wednesday afternoon to Sunday morning. The camper worked so well that I forgot we didn't have shore power a couple times. We were running the furnace at night (temperatures down in the 40s each night), plus we had some rain, albeit in the evening hours mostly, so it didn't interfere with charging from our solar system. We were also using the water pump, including taking showers, and we used the fans during the days sometimes. Most of our commonly-used lights are LEDs.

I did run a generator twice, but both times it was to run the microwave. The batteries were already charged when I fired up the generator.

We have three 70 or 75 watt panels, but given their age, they're probably not producing more than 60 or 65 watts max. There is also a third battery, which I think isn't strictly necessary. There's also a giant inverter installed that will run everything but the A/C. This system was installed by the original owner, although I upgraded the solar charger to a three stage version.

I was saying to a friend that I have no idea how long our batteries would last for us before needing recharged, because every morning the sun comes up and starts charging them again. I guess I could wire up a switch to shut off the solar system, but I can't think of a good reason I'd need to do so normally.

My only gripe with the system was that we don't have enough 12 volt sockets to plug in phone chargers. In particular, there are none by the bed, where we usually keep our phones at night. I've ordered two off Amazon to rectify that oversight; I'll install them in the closets next to the bed and connect them to the wires for the lights that are already there.

[weirdstuff]

We're sold on getting more solar. Thanks for the great input and info.

Now, need to figure out where to buy and install them.

We're in San Diego. Anybody have ideas? (and not at our local dealer). Any "highly recommended" places in California?

[K9CarCrate]

Weird stuff, this is my rig and I love the solar upgrade that I had completed in March 2014). I have talked to Ohio (in November 2013) and I personally don't think they have adequate knowledge. There is a thread, "Solar Power Upgrade" that has a detailed write up with the help of a fellow member, "Lewster" who is in the business of installing awesome solar systems. It depends on what you want to run, (in my case, everything except the A/C, and boondocking in the dead of a New England winter. I have an additional 1.7 cubic foot freezer. Just so you know, there really isn't a reasonable solar system to power A/C...I can't say enough about Lewster's knowledge, attention to detail , innovative ideas, and he stays up to date on the latest technologies. You are in luck since he just migrated to Oregon from Naples, FL for the summer. Let me know if you need any further information. Steve.

[weirdstuff]

Steve, Appreciate your advice. Who did your solar installation, and what brand panels are they?

[K9CarCrate]

Weirdstuff, they are GP-100 solar panels and Lewster did the entire installation. He is now close to you for the summer--Oregon.

[weirdstuff]

Originally Posted by K9CarCrate

Weirdstuff, they are GP-100 solar panels and Lewster did the entire installation. He is now close to you for the summer--Oregon.

I just pm'd Lewster.

Also, just to give you some perspective on west coast geography, San Diego seems to be about 1150 miles from Hood River, OR. If we head straight north, it takes us 3 days just to get out of California!!

May be re-routing our cross country trip to include Hood River.

[K9CarCrate]

Weirdstuff, I'm good on geography...only 1150 miles??? Time for you to get into your Airstream Interstate and go for a real drive!!! That's about the same distance from Northern Virginia to Naples, Florida. Just for a perspective on east coast geography.

[weirdstuff]

Originally Posted by K9CarCrate

Weirdstuff, I'm good on geography...only 1150 miles??? Time for you to get into your Airstream Interstate and go for a real drive!!! That's about the same distance from Northern Virginia to Naples, Florida. Just for a perspective on east coast geography.

No kidding!! Looks like our cross country trip might have just gotten a little longer, and a little more northerly! Husband is on board with this small detour, so that's good!

Waiting to hear back from Lewster. Lewster...are you out there?! Sent you private message...

[K9CarCrate]

I am POSITIVE Lewster will get back to you! Probably working. You will not be disappointed. If you come east of the Mississippi, let me know--would love to meet up with fellow dog traveling crazy streamers!!!

[weirdstuff]

Originally Posted by K9CarCrate

I am POSITIVE Lewster will get back to you! Probably working. You will not be disappointed. If you come east of the Mississippi, let me know--would love to meet up with fellow dog traveling crazy streamers!!!

Lewster already got back to me! More info to come soon.

We will be east of the Mississippi! Have to get to Newport, Rhode Island. Not sure what route we'll take. Good chance we'll be headed to Luray, VA on the way, to meet some friends. (I grew up in VA. JMU grad.) But will probably avoid NOVA. As you can see by today's possible route adjustment...we're flexible!!

Would be fun to meet up and laugh about how our dogs rule our Interstates!! Who knows...maybe by time we're east of the Mississippi, the dogs will have taken total control and we'll be riding in the back trying to stick our heads out the windows!

When we leave on this trip, maybe I'll start a thread and see who all we can hook up with on the long long journey!

[Ron_CA]

Airstream is boosting solar to 100w for 2015. I have a feeling you will end up with much more than that if you talked to Lewster

[weirdstuff]

Originally Posted by Ron_CA

Airstream is boosting solar to 100w for 2015. I have a feeling you will end up with much more than that if you talked to Lewster

haha!! I think talking to Lewster is gonna end up costing us a lot of time and money. But, I mean that in a good way.

[73shark]

Originally Posted by weirdstuff

We will be east of the Mississippi! Have to get to Newport, Rhode Island. Not sure what route we'll take. Good chance we'll be headed to Luray, VA on the way, to meet some friends. (I grew up in VA. JMU grad.) But will probably avoid NOVA. As you can see by today's possible route adjustment...we're flexible!!


When we leave on this trip, maybe I'll start a thread and see who all we can hook up with on the long long journey!

Give us a shout if you come thru Kansas City.