Dry Camping with solar

[Nicehobbits]

Looking to add some extra battery storage , possibly 2 deep cycle 12 volts in the rear LPG Storage box , it's a great place , think plastic lined & vented .

I'm looking to add a solar panel up top at the front of the overhead bed area .... I've seen a great deal at the mart .. Anyone have any joy with a solar panel from Walmart ? . I don't want to be going crazy with $$

Just looking to be able to have some lights for the evening & possible running of 1 roof 12 volt fan to move some air ..

Sun will not be a problem on our planned trip into Mexico .. Having power backup will be awesome

[jmowrey]

We bought a 100 watt panel from WindyNation.com. I don't know a whole bunch about solar panels, but this products seems very well made and seems to do the job. At the time I was searching, it was one of the better priced panels I could find. ($179) They sell kits as well, but I put together my own system. I use a dual controller. That way, in the winter, I can use the panel to trickle charge both the vehicle and the coach battery so there is no need to take the batteries indoors for the winter. The whole system, including good quality solar wire, code grade connectors, etc. cost about $450.

If you're only looking to run a few lights and a fan or two, I'm not sure why you're thinking of adding so much extra battery storage. But I guess the more the better. But you mentioned you were on a budget. We have never had any problem running our lights (we replaced all the bulbs with LCD bulbs) and a fan, an air filter (for my wife's allergy relief at night) water pump, and also the furnace fan as much as we need to. The panel charges up the battery quite quickly the next day, even without full, direct sun. The stuff we run during the day (which isn't much because we aren't inside during the day that much) is powered essentially by the panel (through the battery) so the battery doesn't deplete during the day. I haven't done all the math, but from experience I can tell you that the single 12 volt deep cycle battery we have has rarely run below 70% from overnight usage, and as I said, it rarely takes more than half the next day to recharge it. This panel charges even under cloudy conditions, though obviously not nearly as much.

As a caveat, I can't say we've done any extended boon docking during rainy, cloudy weather. Perhaps my system would let us down under those conditions. I'm not sure. But in that case, we would go to serious power conservation mode, and I assume it would be okay.

As an added note, I didn't mount the panel. Instead, I ran the cables from the solar controller mounted inside the coach out through the storage compartment where the shore line power chord lives. I've got about twenty five feet of line there which I coil up and store in the compartment when not in use. When we are on the road, I hang the panel from brackets on the wall in the bathroom in the coach. It fits there just fine and isn't it the way. When we set up, I take the panel out, hook the cables to it, then I can position the panel on the ground outside wherever I need to in order to get good sun exposure. I put a simple hinged wood brace on the back of the panel so I can prop it up for the best sun angle. I can move the panel throughout the day to track the sun. But this hasn't really been a big issue. I usually just set it up in a sunny spot and forget about it. I only move it if it winds up shaded at some point. I also carry an extra 25 feet of extension cable, just in case. Which means if we are ever in a seriously shady place, I can move the panel up to 50 feet from the coach to find sun. But I've not had to use the extension cables yet. Usually there is enough sun within reach of the regular cables to do the job.

Since our objective is to park in the shade whenever possible, this plan seemed preferable to mounting the panel permanently on the roof where it's likely to be shaded most of the time, assuming we find a nice shady spot to set up.

Good luck!

Joe

[Nicehobbits]

Thanks Joe

Some great tips you have ... Upgrading to led bulbs sounds a good idea .. What would be the best place to get a deal on them ? .

What is the actual size of your panel .. It seems a very easily stored unit .... The extra cable is a good idea ..

Thanks again

[stamar]

ive got a unisolar stick em panel 120 watts installed

and i have another one i never installed actaully sitting in my rv because i never finished getting the right controller ( i only have a controller that works with 10 amps.

http://www.ebay.com/itm/Peel-Stick-136-watt-Uni-Solar-Laminate-Solar-Panel-Flexible-24v-Unisolar-/271309735440?pt=LH_DefaultDomain_0&hash=item3f2b520610

i drilled one hole through the pipe cover that goes through the closet in front of the bathroom, and ran the wire there to the controller which stays in the closet, and then another wire runs to the battery compartment.

I never finished putting a 2nd battery in the coach but i plan too.

i got mine for cheaper than this but they are still available. they are very light and pretty much the perfect thing for an rv roof. this is very large its larger than the whole roof and needs to be trimmed but you can cut them right off.

my roof only has room for two like this between the vents and stuff.

i think you should upgrade at least two or 3 interior lights to led that way you can use them all of the time. the other ones you can use very sparingly and keep incandescent....

those bulbs use tons of battery power.

moving a solar panel around has definitely never appealed to me and creating an unecessary project is something id always like to avoid so Im pretty sure i installed my whole set up in like 20 minutes. but if you have lots of free time you can have tons of gadgets. I think as you invest more and more in solar for your rv youll end up putting in a few different concepts. I doubt i will I think ive got it figured out.

[Nicehobbits]

Thanks Stamar

I'm going to do a test ... Make sure house battery is fully charged & over night run my roof fan & maybe 1 light to see if it would last a night ..

Thanks again

[WME]

A 100w panel is about the minimum for real long term boondocking. You will need more if your winter camping and running the heater.

You can do with less, but then you have to watch usage and be careful. To me the idea of solar should be in the "no worries mate" class.

Use what 12 power you want and still have a full charged system at sunset.

[Nicehobbits]

WME ...

Our planned trip is south this winter into Mexico ... So sun will not be a problem , as long as we are not in the shade too much ey ..

We will not be long term boondocking , more traveling .. But we would like the backup of a little solar when camp for 3-5 days with no campground hookups .

Thanks for the input

[WME]

If you drive 3-4 hr each day you really don't need solar. A 100ah battery and LED lights would go 2-3 days. Add 75-100w of solar and your in the "no worries mate" class, in Mexico I don't think your going to be running the heater much.

[Nicehobbits]

Very true .. No heater fan .. But I will want to run 1 fantastic fan to bring in some cool air over the night ...

How long would a roof fan run for y'all think ? .

It's cool enough at about 1500kms down the coast , but at lower southern areas we need a fan ... No cap'n ground has enough amps to run a ac unit .

[Nicehobbits]

WME .. Could I just put in a extra battery & hook it up to the house battery ... Would the toyota manage to charge both while driving & would the house charger do the same ? .

I have a class A too & the coach battery's are like 3 hooked together .

Thanks again

[stamar]

On a sunny day a 120 watt panel will fully charge a dead 28 size deep cycle. However most cold days arent sunny in the nw. Also if you are discharging your battery every night and recharging it every day slowly it wont last long. I think if it were a daily thing id want 2 deep cycles and 200 watts and thats just to run thr heater 12 hours a day. Im still pencilling in improving this

[stamar]

Yes it would charge it

[Maineah]

I can go 5 days with two 80 amp batteries with out a charge all LED's, accumulator on the water pump no inverters or any real power hogs and I run a Fantastic fan on low speed with a thermostat they draw about 1.5 amps on low. I do have a portable custom made 100 watt panel that I can steer and change the sun angle so I can get max power from the 100 watt rating and that can extend my time to 7 days or more. That being said panels are rated at the equator at noon so as you head north or south the output falls off still if you turn things off you can have a good time enjoying the surroundings just skip the computer and the TV. Your stock system will charge two batteries just fine with a few hours drive.

[WME]

WME .. Could I just put in a extra battery & hook it up to the house battery ... Would the toyota manage to charge both while driving & would the house charger do the same ? . I have a class A too & the coach battery's are like 3 hooked together . Thanks again

Its your RV you can do anything you want to it

The reality of doing 2 batteries correctly is that would cost as much or more as doing a solar setup. Correctly done a 2 battery setup uses 2 6v batteries in series. One battery goes through the other battery.

The cheapskate way is two 12v batteries in parallel, side by side +to+ and - to -. As the batteries age, one battery becomes stronger than the other, so the strongest battery will control the charging. The weak one will get weaker as time goes on because the charger is turned off before its charged.

A crutch is to install a HD battery combiner switch, (1,2, both). Every couple of weeks use the 1 and 2 to charge the batteries separately. This will keep them almost matched longer. If you use the 2 12v batteries its best that they both are about the same age AND capacity.

BASIC battery stuff 2 batteries in series= add voltage, capacity stays the same. 2 batteries in parallel = add capacity, voltage stays the same.

MORE math find out how much 12v power everything in your RV uses. Fantastic Fan, lights, water pump, computer, tv and anything else.

Take a guess as how long each thing runs in a day.

Fan 1.5 amps (low) x 12hr a day = 18 amp hours (AH) a day. LED lights 1 amp x 4hr= 4AH. The water pump uses a lot of power but it only runs 30 min in a day. Do this for all your 12v stuff and then add it all up and get your total power usage.

A size 24 battery has about 80 AH, a 27 size has about 100 AH. For max life span of a battery DO NOT discharge continually below 50% of capacity.

So hit the net and sharpen your pencil up and see what you need.

P.S. everybody lies to themself the first time they do this and end up using more power than they thought, but it is a starting point.

A 100w solar panel makes about 5 amps under perfect conditions. So figure 3.5 amps x 8 HR and you get 28 AH back into your battery each day. Longer days and brighter sun and you might approach 40AH. A good MPPT controller will give you a bit more than a normal PWM controller.

MPPT, PWM ???? ya, more internet reading.

RV power is not rocket science, only close to it if your easily confused

[stamar]

http://www.ebay.com/itm/10A-10Amp-Solar-Panel-MPPT-Batt-Regulator-Charge-Controller-12V-24V-CMP2-/271302708569?pt=LH_DefaultDomain_0&hash=item3f2ae6cd59http://www.ebay.com/itm/10A-10Amp-Solar-Panel-MPPT-Batt-Regulator-Charge-Controller-12V-24V-CMP2-/271302708569?pt=LH_DefaultDomain_0&hash=item3f2ae6cd59

this is the charger i have although i got it for 7$

it works fine. it switches from 24 to 12 volts. so one side can read i believe 28 volts the other side reads 12.5 or some low voltage over 12.

if you are using mismatched or multiple panels you want an mppt controller. however you can just get one cheap controller per panel as you add them too.

mppt in those situations i mentioned can increase charge 30% or its basically smart and switches the volts as opposed to just cutting it off. it has a small brain involved calculator sized.

pwm is best for a 12 volt battery with a 12 volt panel.... one per

i dont have anything fancy keeping my batteries even at all in fact im not even using the same kinds of batteries in the same size. im killing them.

but in the set up I have im going to get rid of both of the batteries and switch to 6 volt golf cart batteries and hook them in series. these are designed to go to complete zero and survive better than the ones we are commonly using. same size only you need two obviously.

that is a natural progression of upgrade to switch to two rv deep cycles and then 2 golf cart batteries. off grid housing does the same thing as you get more serious. by the tyime you have 4 or 8 and youre driving around 1000 lbs of battery you need like a whole battery minder computer to keep the charging even.

the actual amp hours are not that impressive its the thickness of the lead plates that are upgraded. once youve killed a few rv batteries with everyones optimistic rv power math youll see the need.

[stamar]

when and if I get back to finishing my solar set up I want a controller like this

http://www.ebay.com/itm/LCD-30A-MPPT-Solar-Panel-Regulator-Charge-Controller-12V-24V-380W-760W-USB-/121118905347?tfrom=140974128375&tpos=top&ttype=coupon&talgo=undefined

thats going to give me the exact data to come back here and post for you all and have some real life experience about whats really going on.

like about where to mount them etc because my experiment honestly stopped after i installed the one on my roof. I wasnt sure whether to put the next one vertically around the three sides on the back of mine or not and im still not sure.

theres actually a lot going on on my set up that I just really cant even estimate like how well horizontal mounting is really doing.

my panel has been there since december but i really couldnt tell you how much power its making. on a sunny day the battery is fully charged no matter where it started but on a overcast day it might produce nothing.

because lets get real if you throw up 6 solar panels expecting to run your ice cube machine or something youre basing all of this on fairy numbers.

Id do it exactly like I did Id do the minimum investment necessary to get something signifiicant and then learn about how it works.

if solar is your power maker no matter how many panels you have you are committing to using power when its there and using none when its not..... if youre the type that needs lots of power every day you need a generator.

[bufbooth]

Any thought of adding a small wind turbine?

[stamar]

I notice they are cheap on ebay.

[Nicehobbits]

I like the idea of a wind turbine .. I'll have lots a sun on my trip ... So panel would be the choice .

I just want some ideas to have a cost effective back up / make use of the sun for our little rig set up .

[WME]

To keep your pocket book from having a heart attack, you can build your system in bits.

1.A cheap controller and a 100w panel

2. next would be a good mppt controller, a good deal might get you a MPPT instead of a cheapie in step 1.

3. Based on actual experance when you need a new battery decide if you need a 200 AH dual battery set up or if a good, 27-100AH or 31-125AH size, single will work.