Adding Solar Power

[Manual Garcia O'Kely]

Well, we made a reservation for mid Sept in Yosemite, and since none of their sites have power [and you would think that they would want to get rid of generators running plus the pollution, particularly in the winter time], I got off my duff and rigged the solar array on the Teardrop.

I had previously purchased three panels from Kragen, these are 'battery float panels' good for a total of about 600 mA/Hr in full sun, or just enough to keep the battery topped off if I'm not using the radio a whole lot.

Convienently, 1" pipe hangers fit the roof rack for a nice temporary install - temporary as I hope to find a more suitable panel or panels - something that will give me an amp or maybe two amps. Seems that there are very small panels and very large panels and what I need are two panels about 18" wide but 4' long.

To connect to the battery, I'm using a UHF feedthru fitting and a special set of cables using PL connectors on the end to pass the DC into the trailer battery.

[Manual Garcia O'Kely]

Well, we used the lights gently and had plenty of power - not that I was badly worried but the daylight seemed to keep up with our daily demand. I still think I want a larger panel so that I can tap the battery for the HF radio.

I'm thinking 25 to 50 watts at this point - if I got a solar controller, then the 50 watts would not cook the 72 amp hour battery during the non-use times.

Anyway, the mounting system, primititive as it is, works fine.

[wa8yxm]

Sounds like you have a plan.. I'd add more watts though (Tim Alan theory of powering, MORE POWER,MORE POWER)

[Andy N1ORK]

Manual, where did you or will you get your solar panels? I'm looking for the best value for the money. I'd like to do something for portable operations as well as charging a marine battery at my camp QTH in NH. I have AC up there, but would rather operate off (without) the AC supply if I can. Would be great to see any photos of your tear drop solar set up.
73
Andy - n1ork

[Manual Garcia O'Kely]

I don't know where, although honestly, for the money, Harbor Freight has 25 watt panels that are exactly the right size for my application - I have a Yakima roof rack on the trailer and I'm going to mount the panels to the roof rack so that I have plenty of airspace under them. Plus, if you look at my pics you can see there's a skylight/Fan-Tastic fan in the middle of the roof so the panels must accommodate that opening.

HF also sells reasonably sized solar charger controls as well to keep the 50 watts of panel from cooking my 72 AH battery.

Since my battery storage is limited [and there is no practical way to put a bigger battery - the existing one maxes out the potential space], there's little point to more than about 3-6 amps of solar power - more than 6 is hard charging and is simply not needed unless I plan continuous operation of the radio, at which point I strongly consider a campground with AC power OR a generator.

Even if I run my DC/AC inverter [120 watts max] and use that to power the laptop, the inverter draws maybe 4 amps and a movie only lasts a couple of hours - how many can you watch before you fall asleep?

Of course, if we don't get any sun for several days on end, there could be issues. But not here in CA very often anyway.

We did see some campers in Yosemite with some serious panels - one fellow had about 300 watts of panel all on a break-down aluminum frame that tilted 'em as desired. Another guy had an 80 or 100 propped up against his rig, another fellow a couple of 60 watter's on tilt mounts on the roof of his pickup based slide-in camper.

One firm rule with my camper is: No extra work - anything that has to be stowed and unstowed had better have a darn good purpose or forget it!

[McKannick]

Searched around for a small, complete system, the panel, charge controller and battery state monitor. Found this http://www.batterymart.com/p-batteryminder-12v-5w-solar-battery-charger.html
and installed it onto the roof as a permanent fixture. Mostly for the idea of keeping the battery at peak charge at all times, but also for extending the 'off the grid' capability of the rig.
http://web.me.com/mckannick/Site/Photos.html
Haven't yet gone totally 'off line' camping yet, but if we're conservative with power in sunny weather, it may work OK.
If that got to be a habit (going off-line) I would consider adding a second 12v battery to the system so that 'theoretically' would last twice as long, but would also take twice as long to recharge, right?

[w3zi]

I had looked at these at the 15 watt kit they have at Camping World but didnt know of the company that made them (Sunforce). You can add panels to increase the capacity. I have been thinking about adding one to my RV, but kind of hung up with the idea of setting those panels down on my roof in a permanent configuration with epoxy etc. Guess I could lash up a temporary rig to set the panel out when I am camped.
73
Mark

[Manual Garcia O'Kely]

I had looked at these at the 15 watt kit they have at Camping World but didnt know of the company that made them (Sunforce). You can add panels to increase the capacity. I have been thinking about adding one to my RV, but kind of hung up with the idea of setting those panels down on my roof in a permanent configuration with epoxy etc. Guess I could lash up a temporary rig to set the panel out when I am camped.
73
Mark

Several things to consider:

You don't want to flat mount 'em to the roof - they want airspace below for cooling - panel efficiency drops with heat.

Several campers at Yosemite last fall had bolt-on stands to tilt the panels and allow them to be oriented directly at the sun - I'm told if you adjust the panels a couple of times a day you get quite a bit better performance, plus the panels are easier to clean, but damn, they are a pain to set up and take down unless you have large storage [I do NOT].

I'm still looking for a good permanent panel - my loaner went back to the owner.

What I want to do ultimately is allow myself enough solar power to operate the HF rig off the 72 amp-hour house battery on the tear drop, then I can stop carrying a 33 amp-hour gel-cell separate battery. I want to be able to keep the battery topped off when I'm camped for several days at a time.

This would save me quite a bit of space, weight and equipment pieces for what turns out to be fairly infrequent operation. For a real remote operation, larger still would be the batteries, and it's an entirely different situation from my normal travel.

[Dizzy-Dick]

Manual,

I have a question about Yosemiti and other parks without power. Are you allowed to run your generator at night? A lot of the parks I have been in have quite hours, no generators allowed to run all night.

My problem is that I am on oxygen at night and my oxygen generator runs on 120 volt AC only and pulls a lot of amps. One park offered to let me park close to one of their facilities that had power and run an extension cord to my rig.

Sounds like you have good plan going with your solar panels. I see a lot of rigs with small panels and I don't believe that they do any good at all. Probably would not even charge the house batteries.

Happy campings and 73's

[Manual Garcia O'Kely]

Manual,

I have a question about Yosemiti and other parks without power. Are you allowed to run your generator at night? A lot of the parks I have been in have quite hours, no generators allowed to run all night.

My problem is that I am on oxygen at night and my oxygen generator runs on 120 volt AC only and pulls a lot of amps. One park offered to let me park close to one of their facilities that had power and run an extension cord to my rig.


Hm, I don't know what to tell you here - except to say that the ADA might allow you some exemptions, but your neighbors will hate you.

I suggest you e-mail or better yet, call them and ask them what they can do - I'm pretty sure that there are some spaces where you can run a long enough extension cord to a toilet, but many of them up on top of T.meadows simply have no power at all. I imagine that in Yosemite Valley, they probably have a few sites that have access.

I understand your problem, I have an Uncle who has only about 2/3'rds of one lung and lives on a concentrator as well.

[Dizzy-Dick]

Hm, I don't know what to tell you here - except to say that the ADA might allow you some exemptions, but your neighbors will hate you.

I suggest you e-mail or better yet, call them and ask them what they can do - I'm pretty sure that there are some spaces where you can run a long enough extension cord to a toilet, but many of them up on top of T.meadows simply have no power at all. I imagine that in Yosemite Valley, they probably have a few sites that have access.

I understand your problem, I have an Uncle who has only about 2/3'rds of one lung and lives on a concentrator as well.

Thanks for the reply. I do not like to, and will not knowingly disturb anyone. If I get to the area, maybe I could stay outside the park and just take day trips with the "toad".

Never been to California except to fly in on business quite a few years ago for a couple of days. Got the business done on a Friday, went to Disny Land on Saturday, and flew back to Texas on Sunday. I am sure that I am missing a lot. I like to gold prospect and Calafornia has to be one of the better States to do that in.

Thanks again,

[wa8yxm]

If you want to keep a battery topped off while in storage then 15-25 watt might be good.. I have a 5 watt panel that helps.

If you want to use solar to supplement your generator add at least a digit to that wattage, figure 150 watts, min.

Look about at what you wish to run on solar.. Television, LCD's are usually less than 100 watts depending on size may be less than 50, CRT's can run 200-300, Fridge run on gas, a few watts, run on electric 350, Forget A/C or water heater (1000 to 1500 watts each) save for gas heat and perhaps a swamp cooler in the desert (50-100 watts, favor the low end)

Total the number of watt hours, (Don't forget the sat receiver) then figure out how many hours of sun you have, Divide the hours by TWO (If you have 10 hours of sun 10/2=5, Divide watt hours by that result 1000 watt hours per day/5= 200 amp hours of panels.

NOTE: do not neglect your 12 volt loads.. TS-200 in transmit...... Around 150 watts


Second suggestion.. When figuring amps (As opposed to watts) to determine wire sizes and such,,, Instead of using actual battery voltage use 10.

1: It makes for much easier math

2: It gives you a bit of a safety factor

3: It is not all that far from the proper efficency correction for things like inverrters (12*0.9= 10.8, most inverters are right close to 90 percent at peak efficency)

[Manual Garcia O'Kely]

Well, let's see:

72 amp/hour battery

Loads: 4 small area lights, usually used one or two at a time, max of 3 hours a night usually. Water pump for the sink - maybe a minute a day. Once a week we run the computer for a couple of hours to watch a DVD. Sometimes I run the HF radio for a couple of hours of very casual operation. I might recharge my Ipod.

I figure that if I put 50 watts on the roof, flat, I'll average 25 watts, so that's about 1.5 amps.

The radio draws about 600 mills on receive, and with my usual duty ratio, I probably transmit 6 to 12 minutes per hour so I need maybe 7 amp/hours for an average couple of hours.

Since my trailer battery also recharges from the car when I'm towing it, I figure with 50 watts I can dispense with my the extra 33 amp/hour gel-cell that I have carried to run my radio on most of our trips.

That's 25 lb's, and a charger, plus space saved in the towcar.

At a cost of almost $400 even at Harbor Freight. I must be out of my mind.

[Bill Baxter]

I have found solar to be great. We can go about three days without the generator with normal electrical usage. Each panel, of four, is 175 watts at 24V nominal. Battery bank is 750 AH at 24V.
No more RV stuff for us. 120V refrigerator w/ice maker, TV/sat rcvr, radios 2m, APRS, CB and am/fm w/sirius. We use on the order of 200 AH per day. Panels put in about 130 AH plus day load. I start recharge at 70 to 75% battery capacity.

I didn't realize that a teardrop had enough room for a panel or two. Learn something everyday.

Still trying to figure out HF mounting and antenna.

Bill

[Dick Noble]

Been a while since anyone posted to this thread. I'm new here but not to boondocking in an RV. My current system is 250w of solar, 500w wind generator and just purchased 4 - 64w panels so at max I should be able to generate 1KW into 4 12v deep cycle # 29 batteries for a total of 700AH. I use one 1200w (Coleman) inverter for a single circuit 120v (for the TV and HF radio). Everything else is off the 12v system. I have used #2 wire for most of this install so should have minimum line loss. I have also wired the batteries so that incoming current is spread over the entire bank and usage is reversed out over the entire bank - did that make sense? The wind generator is from www.windynation.com and is a PMA 500w one. They have a new system that I wish I had waited for since I think it would have cost less than the home brewed one I put together. PMA generates three-phase AC into a rectifier to 12v so I was able to use #12/3 wire from the gen. to the rectifier (and controller) and #2 to the batteries. I intend to use the 100amp controller for both the PMA generator and the 4 new (used) solar panels since the controller is designed for that. Current 250w solar system is into an MPPT BZ products controller but it is only rated for a max of 250watts. Be interesting to see if this system will stop any use of small gas generator at Imperial Dam. AZ Dec. and Jan.

[Andy N1ORK]

Sounds like a nice system Dick! Pics would be great!
73

[WD8QBQ]

Dick, that all sounds interesting and appealing, well the solar anyway. Not sure about the wind gen. sounds too laborious to setup unless you will be one place for a real long time, maybe I don't understand it all.

You sound like you have a lot of experience. You will be a strong asset to our group.

JIM :)

[Dick Noble]

Sorry that I do not have any pics. I'll work on that. Setting up the wind gen. isn't to hard - I've built an "H" shaped frame that the mast attaches to in the middle. I pull the 20' mask up with the PU and then guy wire it to each corner of the "H". All of this is 1 1/4" black pipe that breaks down into 8' sections. Wiring runs from a slip ring (that the PMA runs into) down the outside of the pipe to the 100amp controller. The Controller has two 300w dump loads attached since a wind generator has to have a load on it at all times. This is hard to discribe. Guess I'd better work on pictures. I'll try to get some after we set up in December.

[Dick Noble]

Jim, thanks for the kind words.

[Dick Noble]

Here is a URL that might help wiring a battery bank:

www.smartgauge.co.uk/batt_con.html

Note the last part about how to wire the generators. I have to change the way I did it.

[WD8QBQ]

Dick, that's a real good site to add to my library :worthy:

I'd like to share one with the forum, it's rather obscure and not likely to be found, but may be useful to someone with a specific and difficult question they need answered. I have asked questions there and it is unbelievable how fast a detailed answer appears. If you use the forum be sure to read the rules first, :poke: :D

http://forum.allaboutcircuits.com/index.php

Thanks, JIM ;)

[Dick Noble]

For those who are really into solar and boondocking - look at

www.solarovens.net

This site also has a solar tracker for their ovens.

[Bill Baxter]

Solar panels: 4 at 175 watts/24VDC, max voltage 32.4VDC. Wired series parallel for 48V to controller. Controller is an MPPT and feeds the 24V house batteries. Six AGM's 8D at 250AH wired series parallel for 24V system. Batteries feed a Trace 4024 for AC supply. We can go three days - four if good long sunny days- without going below 50% charge. We don't skimp on usage. TV, sat dish, micro/convection, lights are all used liberally. Radios are a sometimes thing still trying to figure an easy antenna system. I don't run the generator unless I have to.

Bill

[WD8QBQ]

Hey Bill, :poke: time to get out of Maine, don't you think.

Oh by the way, I don't run my generator unless I have to either,:whistle:.

Just kidding, couldn't resist:bag:


JIM:D

[dmreese1]

http://handybobsolar.wordpress.com/2009/07/22/solar-power-that-works/

The link above is a great down to earth solar / boondocking information source. Bob has been there and done it and offers tremendously valuable advice.

I installed a 135W Kyocera panel and a 3 stage charge controller on my 2005 national RV - Tropical roof. I wanted a good charge source that would fully charge my 470ah battery tank with the correct (14.8V) voltage. I also installed a Trimetric monitoring system and it is terrific.

Only have about 7 amps in full sun, but I wired 4 guage wire from the roof to the controller and have the room and controller amps to add 3 more later on.

Duane

[wa8yxm]

Generally you are NOT to run a generator at night.. If you need O2 you can use a concentrator during the day (On Generator) in most parks, but I expect some will even object to that.

You can always use Tanked oxygen... That is about the only choice, the old fashion way like my mother, and my priest, both used to do.

Fun fact: Poor Fr. his tank ran empty and guess who, in that great big parish, knew how to change tanks (Well... I did not know but I have enough training to look at the job and figure it out on the fly and make it LOOK like I knew what I was doing... Fact is.. I had done it before but hey.. about 1960's so it had been a while)

[Bill Baxter]

http://handybobsolar.wordpress.com/2009/07/22/solar-power-that-works/

The link above is a great down to earth solar / boondocking information source. Bob has been there and done it and offers tremendously valuable advice.

I installed a 135W Kyocera panel and a 3 stage charge controller on my 2005 national RV - Tropical roof. I wanted a good charge source that would fully charge my 470ah battery tank with the correct (14.8V) voltage. I also installed a Trimetric monitoring system and it is terrific.

Only have about 7 amps in full sun, but I wired 4 guage wire from the roof to the controller and have the room and controller amps to add 3 more later
on. Duane

Trimetrics is the only way to go for a battery monitor. I had an E Meter on the other coach but alas no longer made.

My max has been 26A at 28.2VDC. That's within less than half an amp from the panels maximum. Wired two panels in series and then to (#10 UF) Outback MX60 controller and on to the battery bank. Current flow in the #10 wire is only 6.5A I don't think the voltage drop over 12 feet is worth consideration. Maybe wrong as I didn't do any calcs. Just a SAWG.

Is is fun to sit in a boondocking campsite without the generator running everyday. Especially when the neighbors are running their's morning and evening for a couple of hours.

Cost effective probably not but is fun.

Bill