Solar Setup Advice

[JJMAC]

Ok. Searched and searched. I am looking for a simple Solar setup for my popup camper.

Camper is used 100% off the grid.
I have one battery.
Power is used only for interior lighting and occasional use of heater on cold nights...

Looking for a system to help replenish battery. Nothing crazy. I have been 4 days on just the battery an had enough juice. Looking to make it 7-10 days.

Any recommendations?

Are these systems junk?
http://www.amazon.com/Instapark%99...1089978&sr=1-4

 

[LandCruiserPhil]

Ok. Searched and searched. I am looking for a simple Solar setup for my popup camper.

Camper is used 100% off the grid.
I have one battery.
Power is used only for interior lighting and occasional use of heater on cold nights...

Looking for a system to help replenish battery. Nothing crazy. I have been 4 days on just the battery an had enough juice. Looking to make it 7-10 days.

Any recommendations?

Are these systems junk?
http://www.amazon.com/Instapark%99...1089978&sr=1-4

Link no workie

Why not an extra battery if you needs are low

 

[JJMAC]

http://www.instapark.com/solar-panel-solar-powered-products/30w-mono-crystalline-solar-panel-with-a-12v-solar-charger-contro_spcc-30w.html

How bout this one...

 

[JJMAC]

"Why not an extra battery if you needs are low"

Trying to keep tongue weight down and I figured that this would also last longer than a battery and be about the same price...

 

[pods8]

http://www.instapark.com/solar-panel-solar-powered-products/30w-mono-crystalline-solar-panel-with-a-12v-solar-charger-contro_spcc-30w.html

How bout this one...

Well if you're looking at that watt range for panels, your link is $135 for 30W & controller and they don't tell you much technical info about the components. Lets assume an inexpensive controller.

Or $80 for 35W panel and $25 for a basic sungaurd controller by morningstar which puts you at $105 with money left to spare for wiring.

 

[Hafwit]

I recently got some great products from a company called Goal Zero. They have some great solar and LED products that could work for your setup or could be used for other things as well. The person I spoke to also said that they will be at the upcoming Expo in Amado.

Cheers,
Greg

 

[Black Dog]

I think I'd agree with Hafwit and do some work on limiting your power consumption. It you upgraded all your lighting to LED from incandescent you will get a little more time out of your existing batteries. Thats how it goes when you are taking a house off grid any way, reduce your consumption then evaluate what you need as far as batteries and panels.

I remember a while back being told that you figure how much power your system will use when everything is turned on, then go 50% higher that that for solar panel wattage. I don't know if that is the official industry standard but it would be a good rule of thumb to go by.

 

[traveler57]

do the math first

I was looking at adding solar too. But find any of the big solar websites and their users and they will show you why they always seem to have 300w to higher systems. A LOT of great information out there.

I then did the math on how many Watts of solar equals what capability to recharge a battery.

For a 30W (2amps at 15Volts) it would take you ~25 hours to recharge my 100ah battery that is 50% down. (Yes, this is not exact but it can be used as a rough rule-of-thumb.)

And this is 25 hours of perfect and bright sunshine. Any thing less and you will have less than the 2 amps. so 25 hours is your best possible.
And, the math --- assuming a perfect 4 hours of sun a day, means you can recharge you 1/2 down battery 5 days! (if you are not using it at all.)

So first thing I learned was that people using solar for serious off-the-grid camp use, will start at 250-300W minimum. but now you are talking $1000 for the nice systems and $300 for Harbor Freights cheap version.

So does solar work? Absolutely!! Do you have to pay big bucks for a system that actually does something for the off-road camper? YES.

This does not say that a less expensive 30-100W solar panel will be not a good thing to have. It can help, for sure. If I can stretch out my 3-4 days off-road to 5 just by having a little panel, I would love it. But for $1000?? or even $300? for me I just went with a second 100ah deep cycle for $80 and 52lbs of weight. (I can charge both batteries with my on-board 45amp charger in just a few hours, the night before a trip.)

Another point mentioned a lot. If you camp in the desert or the wide-open spaces in Utah, AZ, NM, solar can make a lot of sense, If you camp in tree covered forests most of the time, then your "sun time" will be tiny.

I am not saying that I will never get solar, since I probably will someday. but I am just pointing out the cost to benefit ratio is not clear (and not low enough) for the causal weekend camper. Many people looking at solar (including ME) think we can get much more charging capacity for the $ than is actually possible.

Even a 30W panel that can put out 2 amps.... well it will at least take a bit off my 4amp fridge draw.....

Yes, just my 2 cents, but something to consider when doing the math.

 

[pods8]

For a 30W (2amps at 15Volts) it would take you ~25 hours to recharge my 100ah battery that is 50% down. (Yes, this is not exact but it can be used as a rough rule-of-thumb.)

Just as a point of clarification, part of the goal with smaller sized solar systems is not to hook a heavily discharged battery up to it and recharge, its to be adding current during the daylight constantly so the net effect is a slower discharge of the battery over time (after the trip it can top off/condition the batteries).

There is obviously still a cost/weight benefit analysis each person has to do for themselves.

I see no reason a small rig that isn't a power hog would need to be on a 300W system, thats a hell of a lot of amps in good light. In the SW that would recharge 100ah a day, who the heck uses 100ah a day?

 

[traveler57]

pods8,

don't worry, I totally agree that not everyone needs 300W. and no, I don't need 100ah per day. that is just my battery size. No one can discharge a battery with all 100ah down to 0, anyway. It would be a dead battery and junk. But using up to 50ah in several days of camping is very typical of a lot of people (including me) might do with "normal" use with a fridge.

But yes, each person will be different.

And, yes, my whole point was that each person should do their own math to see what they get for what they spend. And as I said, I fully agree that having even any recharge going on with a small panel will still result in a net gain against having nothing. So, someday I will buy a panel too.
(Maybe even the HarborFreight panel for $260??) Just to lengthen and stretch the time (as you and I agree) I can last, and not to think they will "recharge" my batteries.

My post was only because during my own research on solar, I have read hundreds of posts where people are thinking that solar is the answer to everything. (not this poster) I even saw more than one post that asked if they could run their AC off of a solar panel...... (again not this poster)

So back to the posters question of looking for input and advice. Each of us has our own ideas and that is why this forum is really a good place. so with my 2 cents and your 2 cents I think we have a nickel!!!!

 

[pods8]

pods8,

don't worry, I totally agree that not everyone needs 300W. and no, I don't need 100ah per day. that is just my battery size. No one can discharge a battery with all 100ah down to 0, anyway. It would be a dead battery and junk. But using up to 50ah in several days of camping is very typical of a lot of people (including me) might do with "normal" use with a fridge.

My 100ah comment was just a round number off a 300w panel w/ 5hrs of light 300w/14v*5hrs = 107ah ~100ah (one would assume you'd porbably be running MPPT with those levels of wattage so you won't be throwing away the extra volts). It had nothing to do with your battery size mentioned earlier and was more towards the "250-300W minimum" comment you made. Even with only 1 hr of good light 300W of solar is going to throw off ~21ah, I just don't see how small camper and trailer rigs would need anything of that nature and that is what I was calling attention to.

I agree with each person needing to decide whats best but if you're in a sunny spot I'd give solar a tad more credit than you are. 50ah over 3 days is ~17ah a day. Assuming you can get 5hrs of good sun and your using a basic PWM controller 17ah/5hrs*14V= 47.6w of adjusted solar, 47.6*18V/14V= ~60watts of panel most likely needed. That is ********** in the 30-100w range you were blowing off. You can pick up an 80w panel and a Morningstar Sunsaver SS-6 for ~$200. That isn't quite as our of reach as you might think and if you're only using ~17ah a day that will extend your 3-4days much more than 5 even in less than ideal light. 80w/18V=4.45amps (not I didn't account for MPPT here, this would be PWM numbers), 4.45amps per hour of good light. Only got 2hrs of good light? Well now you're only having ~8ah deficit a day, you've just doubled your stay. A little over 4hrs and you're coming up even.

But yes only around 30W doesn't do much unless you're a much lower ah user, which someone without a fridge might be (the OP didn't say anything about a fridge so I was just showing him a cheaper source for a panel/controller in the range he was looking at).

 

[Hafwit]

You might also want to consider wind power in certain locations. There are portable turbine generators that can put out 600W in the right conditions. I think I saw a setup at Northern Tool that did this. You might even be able to combine solar and wind if you want to.

Cheers,
Greg

 

[bdosborn]

Ok. Searched and searched. I am looking for a simple Solar setup for my popup camper.

Camper is used 100% off the grid.
I have one battery.
Power is used only for interior lighting and occasional use of heater on cold nights...

Looking for a system to help replenish battery. Nothing crazy. I have been 4 days on just the battery an had enough juice. Looking to make it 7-10 days.

Any recommendations?

Are these systems junk?
http://www.amazon.com/Instapark%99...1089978&sr=1-4

Here's link to a great price on an 85W solar panel.
Sun Elec Linky

Get a Sunsaver 10 controller and you'll have a nice starter system. Just add another 85 watt panel if it doesn't keep up with your usage. But I doubt you'll need more if you can go 4 days already. Our teardrop had an 80 watt solar panel and we could camp as long as the sun was shining. We didn't need to tilt the panel, we just left it flat. BUT, we optimized for low battery draw: LED lights and no heater.

Teardrop PV System

Our new trailer has 220 watts of solar panel but its a bit overkill. We're usually 100% charged by noon.

Boxcar PV system


Bruce

 

[rdsk8ter]

Here's link to a great price on an 85W solar panel.
Sun Elec Linky

Get a Sunsaver 10 controller and you'll have a nice starter system. Just add another 85 watt panel if it doesn't keep up with your usage. But I doubt you'll need more if you can go 4 days already. Our teardrop had an 80 watt solar panel and we could camp as long as the sun was shining. We didn't need to tilt the panel, we just left it flat. BUT, we optimized for low battery draw: LED lights and no heater.

Teardrop PV System

Our new trailer has 220 watts of solar panel but its a bit overkill. We're usually 100% charged by noon.

Boxcar PV system


Bruce

I just read your build up from now on check K&K raither then den col they stomp there prices if you can find it scrap out back (fairly good size yard) its 50 cents a pound. got a link to where you bought the bigger solar panel?

 

[bdosborn]

The big panel is a 135 watt Kyocera and I got it here:
Arizona Wind and Sun , which is a great company. I bought a battery hydrometer from them last week and it arrived broken. They sent another one out ASAP, no questions asked. Didn't even have to send the broken one back.
:wings:

Bruce