Solar Power- Pauper Power Charging

[dmbecke]

Following, we too added a 200w Renogy suitcase portable unit with an extension wires for $400 and hope this keeps us [emoji4]

[Troutboy]

Ray,

Glad you made the jump to solar finally. You will,like it. With the places you camp, there will be plenty of sunshine. You know our system, and I can tell you a year in now, and we have never been below 87%, the solar panels keep the massive lithiums charged all the time. Even running furnace for 4 days in a row, cold weather spring, but sunny skies.

Our system can handle the microwave and the hair dryer, but that doesn’t happen often, we mostly just use the same stuff you do, lights, water pump, furnace, hit water heater, and fridge.

I would recommend that you consider a second panel, and you can make a suitcase out of it. It will double your input. If you find yourself not charging full in a day, add a second panel.

I have 200W portable on 25’ cord, because some places we go it’s shaded to keep cool like you said, and the 200W in Colorado sun does perfect.

One primary reason I went lithium was because of the weight. I used to tow with JCG, and my payload was, well challenged. Since I got a new ford pickup, payload is not an issue anymore. I likely would have went AGM if I had this payload.

Don’t get me wrong, I love the lithium, but so far for our type of camping, I have et needed the capacity yet and could have went with the much more cost effective batteries.

Good luck and enjoy, keep,us posted.

[uncle_bob]

Hi

If you really want to dig into this, there is a balance between "how much solar" and "how much battery". Oddly enough people are different in what they do and what they need. Who would have guessed ? It quickly gets tangled up with "how much battery". Do you need batteries that will hold out for two days? That depends. Do you need solar that will recharge two days usage in one day? If so The guy selling panels is on the phone right now to take your order That's not to say it's a bad setup, just that it has a cost.

What am I going with? Way more lithium that is needed for a day or three. Enough solar to handle most of a typical day. A charge setup that *will* recharge the battery bank off of the TV in a long-ish day of driving. No it's not a one size fits all solution. It's unique to our situation as we see it right now. For us, physically getting enough lead acid into the trailer to do this ... not so much. Call back in 10 or 15 years and I'll know how good or bad a decision it was

Bob

[PKI]

Bob - there is one more approach ...... use less power for the one day or three when you occasionally stay off grid. That usage does not justify a huge expense. That's why this thread has value. Same decision process occured for us. Solar .. oh, so expensive. Bigger batteries, oh, so expensive and problematic to install - getting less so, but that's another thread. So, generator! Buy one! But experience proved lower use with some ability to recharge would work. Who knew ..... the experts don't tell you that. You figure it out. Or you learn from threads like this. If you live off grid, you need lots of solar. If you live at FHU, you pay the park and don't need solar. The problem is the middle ground where you will spend two-four days off grid. What to do? Read about how the pauper does it. Your concept about matching battery and solar capacity is worth the discussion, just not on point for this thread. Thank you for the reminder. It's part of the overall learning curve. Pat

[uncle_bob]

Hi

Solar's value depends a bit on what part of the country you are in. If you camp in the part of the country where they have these things called trees ( yes they do exist ) .... parking under them provides shade in the summer and limited protection from this and that in the rest of the year. Unfortunately these same objects ( look them up on Google if you live in another part of the country ) also block the sun. Solar doesn't go to zero, but pretty close. That re-balances things a bit. If you have (effectively) zero power in without a generator, you need a bit more battery capacity.

What we have found over the years is that a good percentage of the time we are in the shade. It's nicer there. That was true when we set up tents. It's still true with the AS. Since that's our preference, we adapt to make that work.

On our trailer, the "parasitic" draw (everything including fridge off ) in the "use" state is over 1/2 A. If on average you use 1A that gets you over 36 AH per day. You will need more than 100 AH for a 3 day stay. Since cold beer *is* a requirement dropping well below 1A average is a bit of a challenge.

Bob

[Ray Eklund]

Have several pages of notes of Solar Pauper Power, voltage readings and observations from our back country adventures of North Grand Canyon to Utah and to Nevada and home.

(Of course, we warmed our hands over the one LED light over the Table, and ran the water pump only when the Blue Heelers were dehydrated... and the beer was too cold for them to drink. Just to save face.)

What was learned from these areas? Well... we do not plan to spend one more day looking for an Off the Grid site in the entire State of Nevada. There is good reason why the majority of people live in two Counties. There is another good reason why there is very little Boondocking available in Nevada. No roads off the paved roads that lead to anything but a dead end and needing brush cutters for turning around...

Crazy Jug Point on the North Grand Canyon rim... the Forest Service built a fence to block off the 'level ground' to any form of camping. This left no parking for visitors, nor any room to set up camp, other than a Mini Cooper with Trailer in Tow. Northern Arizona is off our list of prospects for any further Boondocking.

Utah... there are some good Boondocking sites. But for the mileage to get to a site, it is not worth the effort. The easy access sites are ATV Camps, which is very popular in Utah. The ATV traffic tends to 'wash board' fillings from your teeth from miles of use.

Some ideas for maximizing your Solar Exposure were easy. When it is raining and overcast, well a bit more challenging. The Pauper Solar is effective. Using the read out in the Airstream over the Sink... could be low, correct or higher than an actual reading off the Batteries. But... have photographs and numbers to crunch.

The biggest issue... the continuously running fan to vent the refrigerator. Just disconnect it over night and prop open the vent cover. That seems to work. Surely at evenings in the upper 30's at night and 70's during the day should... Nothing like a Forest Service road with SNOW DRIFTs in late May! Turned us around at 8,500 feet in the Fish Lake National Forest. Great views. Not much to do, otherwise.

[Troutboy]

Ray, I’m still finding Good boondocking places here in Colorado. Any chance you could shoot me a pm or point me in the right direction for a few spots in Colorado you enjoyed?

[Ray Eklund]

Originally Posted by Troutboy

Ray, I’m still finding Good boondocking places here in Colorado. Any chance you could shoot me a pm or point me in the right direction for a few spots in Colorado you enjoyed?

******
Since we Power Paupers, yourself excluded as a mini solar energy plant, I am going to toss this wonderful location as a reward for hanging around this Thread.

Taylor Reservoir. High elevation. Paved road to the reservoir. Hundreds of potential Off the Grid Boondocking sites. Also several restaurants in the area that are well worth the reasonable cost.

Fishing, but check in with the Fly Shop. The big ones below the bridge are more into small mammals and birds, looking at their size.

Cool evenings. Even a Gold/Silver Mine... Star Mine on Italian Mountain... or close to that, to the west of the open areas. The mining community is intact. Why? Because the road is miserable and best for a 'rented ATV' at the local supplier. It will take your breath away... as it is way... way up there. Maybe in the 12,000 foot elevation, but I could be off by a thousand feet more or more or more....

Crested Butte is to the west and you would think you were going to Switzerland. If you ignore the thousands of tourists at C. B...., keep Taylor Park to yourself.

The 2016 Greenhorn Adventure mentions this. There is a Forest Service campsite not far upstream from the bridge/dam.

See... just hanging around, eating pop corn and picking corn hulls from between your teeth... can produce positive results. Until I mentioned this wonderful, wide open area on the Airforums... you may decide to never ask again.

[Gearheart]

Ray following the 2016 Wy. adventure we bought 2 more 40 watt panels to add to the mix. I then mounted them on 1x1 aluminum rails and glued them onto the roof on either side of the AC. My big power hogs are the CPAP and the furnace fan. All lights are LED and the stove, fridge and water heater are old school with pilot flames. Camped at Lake Tahoe, in the pines, the batteries were still recharged before noon on a clear day. It is amazing what just sky glow can do.

[Ray Eklund]

May 25 12.4v--- 5:53AM No Solar 35F
12.5v--- 6.06AM Solar Full Sun
13.6v--- 8.10AM Solar Full Sun
12.7v--- 7:15PM No Solar

May 26 12.4v--- 5:18AM No Solar 39F
13.6v--- 8:00AM Solar Full Sun
12.5v--- 7:30PM No Solar
12.3v--- 10:30PM No Solar

May 27 12.2v--- 2:36AM No Solar 33F
12.5v to 13.2v--- 5:40AM-5:55AM Full Solar

(When this posts, the 'columns' move...)

- Days attached to Pickup are not included when traveling.
- Generator was not used.
- Solar panel was moved with Sun when needed.
- LED lights, minimal water pump, Radio in Evenings.
- Temperatures from 33F to 73F at 8,000' elevation in Utah.
- Two days of showers in Utah and Nevada. 5-28 & 5-29
and connected to truck while towing.
- Disconnected Refrigerator fan at night.

[Ray Eklund]

I took my compass and when the sun rose, took a bearing to the East. In the afternoon I took the reverse bearing and set the solar panel that direction. In the morning I could tweak the angle when necessary. Same with post Noon sun.

When we hiked back to camp, I propped up the Solar Panel for maximum exposure. Panel had a temperature, from our temperature remote, 33F to 104F outside in direct sunlight. During 'high noon sun' the panel was laying flat on the ground. I used two milk crates with rock in them to prop Solar Panel for for maximum sun exposure.

-It rained for two days and we were on the... move.
-Days of driving and solar were better voltage readings, and not included.
-I would set the Solar Panel up for Sunset towards sunrise the previous evening.

Solar panel was stored on the bed. Never moved when traveling off road or highway.

I am going to install a 'suit case' handle on the long side of the Solar Panel.

[Ray Eklund]

Three Solar Panel photographs in use.

- Sunrise at North Grand Canyon near Crazy Jug Point, Arizona.
- Sunrise in 'as above' following sunrise in morning.
- Setting up Solar Panel for Sunrise, Fishlake National Forest, Utah.
- Snow Drift closing road in Fishlake National Forest, Utah at 8,000'+.

[uncle_bob]

Hi

Ok, time for a bit of battery nonsense:

As much as I enjoy camping in the 30's and 40's ... batteries really don't. The fact that their capacity drops is pretty well known. The fact that the "magic voltages" change is not quite as well known.

If you shut down at 12.2V ( or 12V) at 70F, the shutdown at 32F can be 12.8V ( or 12.6). Exactly what it is depends on battery chemistry (lead alloy) so it's only a guess. Full charge at 13.6 and 70F becomes full charge at 14.2 at 32F.

So when the thermometer that reads the air says 39F, what temperature are the batteries in the battery box at? If it's 8AM and there was frost on the ground .... I'd bet they are a bit colder.

So you get into a triple whammy. The battery capacity is down because it's cold. The charger isn't filling them up since it's only putting 13.6V on them. You think you are at 50% at 12V and doing fine .. meter reads 50% so I'm ok ...

Solutions:

1) current based charge monitor the BMV-712 is one of *many* out there.

2) temperature probe on your charger so it measures the real battery temperature and compensates for it.

3) Do all the math in your head and yell a lot ....

Why bother about all this? Well, taking cold batteries down to 12V is just as bad as taking normal ones down to 11.4V. You really nuke them. The net result is spending hard earned cash on batteries more often than you should ....

Bob

[PKI]

Originally Posted by uncle_bob

-- snip -- shut down at 12.2V ( or 12V) at 70F, the shutdown at 32F can be 12.8V ( or 12.6). Exactly what it is depends on battery chemistry (lead alloy) so it's only a guess. Full charge at 13.6 and 70F becomes full charge at 14.2 at 32F. -- snip --

Not well known, yes. First time I've read that info. Maybe my error as the deep details often get whized over in the read.

Never seen a stable voltage of over 12.8v, even with the new multistage converter. So - a couple of questions ...

1. Will a lead acid battery charge to more than 12.8v in lower temperatures or are they just dead on arrival in freezing conditions?

2. What technology addresses this, battery chem or converter voltage used to charge?

And thanks for the info. Thanks very much. Pat

[Ray Eklund]

Uncle Bob... this is why I added the outside temperatures and voltages. You are on top of things.

PKI also adds to the wide variances of what a battery can indicate and without a chemistry lab technician... there is no easy explanation to most of us just wanting a dependable 12v output in our Airstreams.

I recall in my much 'pauper younger days' taking my 1956 VW 6 volt battery into the house in the winter to warm it up. Trying to jump start a VW with a cold battery was a challenge, when it would not start the... first run down the hill. It took three to push it back up the hill...

[PKI]

My chem prof did his studies in Chicago. He said that taking in the battery and draining the oil to heat on the stove was the only way he could get his old car's engine warm enough to start in the morning. He looked forward to the day when he was doing well enough - not so pauper as Ray might say - to just get up and hit the key on a new well maintained vehicle. You got to do what you got to do. Understanding why and how makes all the difference. Pat

[uncle_bob]

Hi

Ok, more battery nonsense:

Most modern solid state charger / converters are quite happy to put out any voltage a lead acid would ever want to see. The guts of the gizmo are not the issue. What is missing is the smarts in the converter to understand temperature and a way for it to read the actual temperature of the batteries.

So, next stop on the strangeness trip is to find a converter that has the smarts in it *and* get a temperature probe *and* work out a way to wire the stupid thing over to the battery bank. ... yikes .... Needless to say this is easier on some models than on others. It's not easy on any of them. Also ... do you have solar? .... hmmm .... well that charger needs temperature information as well. Off to wire yet another probe ....

If this all sounds a bit insane ... you are reading right. It is insane and that's why you pretty much never see a trailer set up this way. The only practical solution is the mark one eyeball on the voltage meter. Hook that up to an informed brain and let the human intervene in the process ( at least to shut things down ).

Indeed another ( somewhat more practical ) answer involves lithium's. They would have done fine at the temperatures listed. Next time your rich uncle ( obviously *not* named Bob ) lets you use his credit card .... go for it

Then there is the "other way". Forget these silly trailer things and use a tent !! No worries about big batteries or solar setups. Just *hope* it does not blow down in the big wind. Hope that the rain didn't puddle *right there* ( yet again ). To much of a puddle brings it down while you are out hiking. .....hmmm .... suddenly batteries don't sound like quite as big a deal ... . ( truth in lending -- in some cases fellow campers *do* un-puddle your tent, thanks again to the anonymous couple in the way outback of Yoho Provincial Park ...)

Sorry to hijack the thread .... I do that so rarely

Bob

[Ray Eklund]

Uncle Bob... your information is well received by everyone that needs an understanding and the confusion that Trailer Batteries create to novices, as myself.

A fixed Solar Panel on the top of the trailer is less trouble overall.

A portable that you can move and direct the sun to panel for maximum performance does offer some advantages. After a couple days, when outside the trailer or returning from a hike, rearrange the panel towards the direct sunlight.

I tested this easily. I stood between the Sun and the Solar Panel and used my... shadow as a guide. With the later morning and early afternoon sun the angle of the panel needed to be propped up with two milk crates, each with some local rocks for ballast. This work fine. I put our remote outdoor temperature transmitter against the panel and the panel can be 50% hotter from sun exposure than the current air temperature.

Overall, this was a 'fair test' of the 100w Solar Panel. Once we find a campsite that the trailer is detached for more than two to three days, will a better sense of how just one panel works out. Putting a handle on the long side center rim will help for one person to move it around to chase the sunlight within tree cover.

For the price of the panel... I am not disappointed. As far as keeping the batteries charged... that will be once a four to five day depending on the Solar to maintain the batteries. As some have said... they may consider a second panel.

[uncle_bob]

Hi

Portable solar that can be rotated *will* be more effective than a flat panel. When it's gray and rainy ( I know ... what's that ? ) neither one will really measure up.

One ... umm .... thought .... When pulling out of the campsite, tossing a rock off of the rear wheel through the portable solar panel is *not* a good way to start your day .... don't ask how I know this ....

*Really* crude way to guess at what a 100W solar panel will do:

100W done perfectly would give you a peak current of 100 / 14 = 7 A. If that goes on for 8 hours you get 56 AH. Best bet with a flat panel is you will see about 1/2 to 2/3 of that number. With care and a portable you may see a bit over 2/3. Yes, that's a really rough calculation and there is a lot left out in any rough set of numbers.

With a tent, all you have to do is figure out how to dry it out ... Until the waterproofing dies ... kid figured that one out at the Grand Canyon ...

Bob

[Glassman484]

Ray, thanks for sharing your experience with batteries, and solar!
We are looking to buy our first AS, likely a 25’ international, and we are very interested in using solar rather than a generator for otg camping. Our local AS dealer wants just under $2800 for the 200a system, installed, so your “pauper” system seems like a bargain!

Glassman