20 watt PV panel $29

[parnold]

I got my 80 watt panel from Solar Blvd last year. Packed well, and shipped quickly. I'm happy with it.

[bdosborn]

Same place has a similar 40W panel @ $55 each.

An 80 watt panel for $110. Almost exactly 1/4 what I paid in 2004.

Bruce

[KenC]

Thanks for the tip Bob, they really have discounted prices.

Last year I bought 2-40 watt panels and and combined them to make a 80 watt folding panel and they have worked flawlessly

I just ordered a couple of 20 watt panels, going to make another folding panel. I think I'll mount the 2-20 watt panels on my tow vehicle roof rack and use it for my back up battery and 12 volt fridge.

[notned]

Handholding time. Currently I have a battery tender hard wired to my shore power cord.

So the panels go to the controller and controller to battery. I understand that but then.....

I have the idea that the trailer (Lights, fan) should be hooked to the load side of the controller, but I'm having trouble thinking of how this would tie to the tender.

[bdosborn]

I have the idea that the trailer (Lights, fan) should be hooked to the load side of the controller, but I'm having trouble thinking of how this would tie to the tender.

The tender goes straight to the battery, it doesn't need to tie into the controller at all. Make sure your total amps (lights, fans, etc.) on the load side of the controller doesn't exceed the rating of the controller or you'll burn it up.

Bruce

[notned]

Fantastic fan. 3 amps. 2 led bulbs and one regular bulb. By my count that's ok,right?
Will my led bulbs be ok? I read some stuff about higher voltages that has me spooked.
Thanks for the help.

I got the sun saver 6.

[Bogo]

Fantastic fan. 3 amps. 2 led bulbs and one regular bulb. By my count that's ok,right?
Will my led bulbs be ok? I read some stuff about higher voltages that has me spooked.
Thanks for the help.

I got the sun saver 6.

On the LED lights and voltages. Some have their voltage controlled by a resistor. You need to supply them with a regulated voltage, or at least a voltage near but under their design voltage. If they have a built in regulator, then you can supply them with any voltage their regulator is designed to accept. Resistors are cheap so they are most often used. Yeah, I know that doesn't help much, but then I don't know what you bought.

There is another thread on here on making a cheap voltage regulator for 12V resistor LEDs. It uses a low voltage dropout regulator to limit the voltage from the battery to 12VDC. When a battery is charged, it's voltage will get a few volts higher than it's resting voltage. That voltage is often higher than a LED string current limited with a resistor can handle.

[bdosborn]

Fantastic fan. 3 amps. 2 led bulbs and one regular bulb. By my count that's ok,right?
Will my led bulbs be ok? I read some stuff about higher voltages that has me spooked.
Thanks for the help.

I got the sun saver 6.

That should be less than 6 amps so you should be good to go. LEDs are voltage sensitive, meaning a small increase in voltage burns them out quickly. Your new solar panel and the battery minder is going to supply 14.4V to your LEDs and they'll burn out if they don't have a regulated power source that Bogo described. I always check the voltage rating of the LEDs I buy. If it gives a range like 12V-15V then I buy them. If it lists 12V only I don't buy them.

You can make a regulated power supply pretty easily though and I have links if you're interested. However, I haven't had much luck with them in the reliability department. Could be because of my soldering skills.

Bruce

[rmclarke]

Bruce,
There is a 25watt panel for $29.99 listed right next to the one for $29
http://tinyurl.com/29-99-solar-panel

I was thinking, $58 for 2 folding 20 watt = 40w
or
$60 for 2 folding 25 watt = 50w


The brands are different though......they are about the same size (I like that) but I noticed it is about twice as heavy as the other one ..good/bad???........have you had any experience with that brand??

I don't know a thing about solar but I would like to learn and you ( and those cheap panels ) have motivated me.

Thanks
Richard

[bdosborn]

The specs look good, there's wouldn't be any problems charging a 12V battery. I don't know anything about that brand but its hard to go wrong at that price. Google "Morningstar Sun Gard" for the cheapest Morningstar controller that would work for this panel. Otherwise a Sunsaver 6 would work great and give you a few more features.

Sun guard

Bruce

[Bogo]

LEDs are voltage sensitive, meaning a small increase in voltage burns them out quickly. Your new solar panel and the battery minder is going to supply 14.4V to your LEDs and they'll burn out if they don't have a regulated power source that Bogo described. I always check the voltage rating of the LEDs I buy. If it gives a range like 12V-15V then I buy them. If it lists 12V only I don't buy them.

Actually LEDs are heat sensitive. To much heat generation over time and they burn up. The light generation process isn't 100% efficient so some heat builds up. That heat buildup is what kills the LED. Keep the heat buildup low so it can naturally dissipate and the LED can last decades. Make the heat generation high enough and it can burn out in less than a second. Voltage sensitivity only comes when a resistor is used for current limiting. What happens is the higher the voltage across a resistor, the greater the current that flows across it. The LED will let whatever current that wants to flow through it flow through. Greater current means more heat builds up and the LED gets hotter. Eventually it gets to much and it burns out.

When I said heat generation over time it means that even high currents can be passed through an LED, but they can only be passed for short periods of time with low duty cycles. Many LEDS will easily handle 10 times their continuous rated current, but they must not be on for more than a few milliseconds at a time, and shouldn't be on for more than a few percent of the time.

One thing you see with many high brightness LEDs is they are attached to a heat sink of some sort. This is so lots of heat can be generated in the, but the junction temperature of the LED is kept low by the heat transfered away by the heat sink.

This MR16 LED bulb has heatsink fins around it to help dissipate the heat generated by the LED:

There is a maximum voltage that the LED can handle, but it isn't an issue with only slight over voltages.

[Vedette]

Okay! To date I have avoided the "Solor Power Issue" completely!
But everyone likes a deal.....so after watching this post for a week before reading it, I have finally given in.
So....do I really need this technology in my Teardrop? Or will it just be another gaget that I would be adding on that is not necessary?
I currently have AC and DC power on board, via a good Deep Cycle 12V Battery, with a Progressive converter, and a 30 Amp Shoreline connector.
Pros and Cons needed???????
Good Roads
Brian

[Bogo]

How long are your camping trips? Do you wish to camp where there aren't electrical hookups?

While I've planned for solar, and figured on possibly 70 to 100 watts initially. I've always figured that my first step would most likely be a Honda generator powering the onboard converter/battery charger to recharge the batteries. After that, then I'd get a solar panel set. In the past, price wise, it was hard to beat the generator method, but now with solar panels so cheap... I haven't run recent cost for capacity calculations. Something also to think about is if we get out of this recession, gas and diesel prices will jump as demand goes back up.

[bdosborn]

Actually LEDs are heat sensitive.

<snip>

There is a maximum voltage that the LED can handle, but it isn't an issue with only slight over voltages.

LEDs are certainly heat sensitive and it's something you should consider when you're installing or building LED lights. I used the metal housing of my light as a heat sink by using thermal epoxy to attach cree emitters.



Heat and voltage are proportional to each other in LEDs - heat build up results in more current through the LED and vice-versa. Here's a good article on heat and and voltage effects on LEDs.

More info on LEDs than you ever wanted.

However, the school of hard knocks has taught me that LEDs are more sensitive to over voltage than they are to overheating. That's why all my LEDs now have voltage regulators, either integral with the LED or added to the power circuit by me. I haven't had to replace one since I added them as opposed to replacing them every other month or so. How did you do yours and are you getting good lamp life?

Bruce

[Vedette]

How long are your camping trips? Do you wish to camp where there aren't electrical hookups?

While I've planned for solar, and figured on possibly 70 to 100 watts initially. I've always figured that my first step would most likely be a Honda generator powering the onboard converter/battery charger to recharge the batteries. After that, then I'd get a solar panel set. In the past, price wise, it was hard to beat the generator method, but now with solar panels so cheap... I haven't run recent cost for capacity calculations. Something also to think about is if we get out of this recession, gas and diesel prices will jump as demand goes back up.

Thanks Bogo
We don't boondock camp very often (or have not done so in a number of years), but we do not always camp in sites that have power. Never needed it before.
We don't normally stay in any one place more than two nights or sometimes three at a Rod Run. We are usually on the move, and I have wired the trailer so that the Deep Cycle
Battery in the trailer will be recieving a charge from the TV while traveling 250 to 500 miles a day.
Solor power has never really entered my mind, but as we have not used our Teardrop yet I have no idea how long I can run all of the creature features I have built into it before I drain the battery.
Good Roads
Brian & Sandi