solar and batteries

[SharonM]

Was looking at solar panels from SunFlex, the 40W ones. It says on the blurb that they can charge 12 volt batteries. Does that mean you can connect two 6 volt batteries together to make them a 12 volt, or you must literally charge a single 12 volt battery?

If investing in two 12 volt batteries for solar power, would most folks use the AGM? Which ones?

Sharon

PS: I know about as much about batteries and solar panels as I do hitches. Scary, huh?

[mmeyer]

You can do 2 six volt in series or 1 twelve volt or 2 Twelve volt batteries in parallel, then you need to determine the amps needed. There are several good discussions on sizing battery needs just search the forum.

[honda03842]

I have Sunflex Solar Panels and have installed them on my trailer and our son's trailer. Mine is basically an 80 watt panel and his is a 70 watt panel.

We use them thru a solar controllers to charge our battery (s). Sunflex 12 volt panels can charge a single 12 volt battery or two 6 volt batteries wired in series.

One 12 volt battery is usually adequate for the typical Scamp sized trailer particularly if you have LED bulbs, are not doing a lot of winter camping where you would be running your propane heater a lot or do not have a CPAP machine. Things like CPAP and Cold weather camping/propane heater require more battery.

If I were selecting a single battery I would go with something like a Trojan 205. They are expensive but last forever. (It seems AGM batteries have shorter life, not from my personal experience but rather comments on the site. Others can chime in on AGMs.)

We use a type 24 marine battery and in combination with our 80 watt solar panel and LED bulbs always have adequate power. As well we have the ability to charge from our tow vehicle while driving.

Hope this helps. Glad to supply more info on our Sunflex panels.

[Wander Weekes]

Sounds like you've got a long way to go, but this page should get you started: Trojan Battery Company

[SharonM]

I definitely need to think about the battery situation in some detail. Thanks all. Norm, I most certainly will need to consult with you about some of this.

Sharon

[Thomas G.]

The AGM batteries are much more expensive. Unless you have a unique venting challenge, I don't see the value of them.

[Steve Hammel]

Plus, 40 watts is very small for dual batteries. If at all possible try to go with 100 watts or higher. If for some reason 40 watts is all you can handle then a single 12v is probably sufficient. Keep in mind that solar systems are just battery chargers. Make sure you have enough battery capacity to cover you/your trailers needs. You would then simply purchase solar charging capacity to maintain your batteries. Going with a bit larger capacity solar panel helps on cloudy days or when you are in the shade. I spent an entire summer at Ocean Shores Wa. under big trees and with lots of cloud cover and still had plenty of charge capacity.

[Thomas G.]

Originally Posted by Steve Hammel

Plus, 40 watts is very small for dual batteries. ........

I agree. Is there a particular reason for pursuing the flexible solar panels? You can get a lot more power in a rigid panel for the same money.

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[Jon Vermilye]

Originally Posted by Steve Hammel

Plus, 40 watts is very small for dual batteries. If at all possible try to go with 100 watts or higher. If for some reason 40 watts is all you can handle then a single 12v is probably sufficient. Keep in mind that solar systems are just battery chargers. Make sure you have enough battery capacity to cover you/your trailers needs. You would then simply purchase solar charging capacity to maintain your batteries. Going with a bit larger capacity solar panel helps on cloudy days or when you are in the shade. I spent an entire summer at Ocean Shores Wa. under big trees and with lots of cloud cover and still had plenty of charge capacity.

I agree. I have a pair of 6V 225amp/hr batteries & a 95 watt panel. While the combination works well, it doesn't keep up more than a couple of days in the shade. In full sun, my batteries are usually back to 100% by noon.

[SharonM]

I would get two 40W panels. Flexible because on the Scamp 16 with AC up there, I'm wondering if the flexibles will fit better. I will of course look at the regular type, but will have to see if a large stiff panel will work in front of the AC. I have NO interest in a portable set up, dragging a panel out from somewhere and setting it up.

Sharon

[Jim Bennett]

My thinking (which doesn't always work good for me ).

It would all depend on how much you draw from the batteries in a day, along with how much sunlight you have to recharge. I would also think it would not matter whether you have a single 12V or 2 6V, because if you draw the same amount power, it would take the same amount to recharge, regardless of configuration.

I do use minimal battery power though, spending all ours days and evenings outside unless it is really miserable out, and even then we tend to set up tarps around a campfire.

I have not used solar myself, but do have 4 rainchecks for a 40W portable setups once it gets back in stock (cost $99). Two are for others, and I may take one or two myself. I have a friend with a 27' stick trailer that uses the same 40W panel, and finds as long as he gets sunlight, he is fully charged easily during the day. Granted, he does camp like us, and cooks and eats outside as much as possible. He does only have a single 12V battery.

For the low cost, I am definitely going to give the 40W a shot, and can report back after some use.

So, is my thinking out of whack, or what?

[honda03842]

We have flexible panels on our roof. We choose them for a few reasons.

We did not want something to disturb the roof line of the trailer for looks and aerodynamic reasons. It is less than a 1/4 inch high. (It is the one of the reasons I do not have roof top AC.)

Flexible panels weigh very little, our 80 watts is weighs 4 lbs.

The flexible panels are not visible from the ground and theft is therefore not a problem.

They take up no inside space and do not have to be deployed. We are generally against deployables like solar panels and coolers.

They collect sun while driving versus the typical deployable panel.

The downside is they are more expensive, and can not be set for optimum Sun.

Our experience is that they have been adequate for our needs. Our needs are LED lighting, charging computer, phones, nooks, running TV, WiFi hot spot and Satellite receiver.

We also have the ability to charge our battery from our tow vehicle while driving.

Personally all solar panels are neat. Solar panels are really neat because they do silently free you.

[Steve Hammel]

Flexible panels are great they just cost far more than rigid and I'm, as the little birdies say, cheap cheap cheap.

Jim is right. It is senseless to buy something without knowing what your needs are. You should first determine what your 12v usage would be on a very heavy use day, factor in a cloudy day and then buy batteries that will cover you. After you determine your batteries and how fast they will be ran down then determine how much solar you will need. If you are plugged in most of the time, with an odd day here and there off grid, then a decent single12v battery is plenty sufficient. If like me and a few others who have 12v fridges and rarely hook up, then dual 6v (far greater amp hours) with a minimum of 100 watts (preferably more) charging capacity is a good start.

[Thomas G.]

Originally Posted by Steve Hammel

Flexible panels are great they just cost far more than rigid and I'm, as the little birdies say, cheap cheap cheap.
............

I'm cheap, too. Solar panel prices have been falling fast in price lately. I hate to spend a bunch of money on something and then see it cost 1/2 as much for a better one in a years or two's time. Anyone got a $5000, 42" flat panel TV?

[Jim Bennett]

Tom, you could never by anything technology wise then, as it seems just about everything drops in price a year or two after it comes out. It seems while I wait for prices to drop on something, a newer better version I like better comes out, and costs at least as much.

[Thomas G.]

Originally Posted by Jim Bennett

Tom, you could never by anything technology wise then, as it seems just about everything drops in price a year or two after it comes out. It seems while I wait for prices to drop on something, a newer better version I like better comes out, and costs at least as much.

I'm typing this on a 1961 Underwood typewriter.

[Steve Hammel]

That's why I'm still holding onto my 7 year old flip razr. As soon as I buy something else it will be outdated. My phone is so old I tell my students that I like "classics" and everything "old school" and they actually believe me. LOL!

[SharonM]

Okay, these are the Trojan batteries (2) I'm looking to buy. Are they the best for someone (me) who plans to boondock a lot?

Trojan T105-RE Deep Cycle Battery Free Delivery most location in the lower 48*.

Second, if it can be mounted on my 16-foot Scamp, instead of the super expensive flexible 40W pair, I spied this one at Amazon:

Amazon.com: Ramsond 100 Watt 100w W Monocrystalline Photovoltaic PV Solar Panel Module 12V Battery Charging: Patio, Lawn & Garden

Good choice or are there better choices out there?

Thanks for any feedback!!!

Sharon

[mmeyer]

Batteries are a good choice , price with delivery looks fair. Have you talked to your local golf course? I was able to pick up some T 145s for about $124 at a nearby course. They liked them better than the T 105 but they are heavier.
Can't comment on solar as My only experience is with UHaul and factory mount.

[Thomas G.]

I'm an admitted cheapskate. I would buy two 6 volt golf cart batteries from Costco and a solar panel from Solar Blvd or eBay.

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