Solar???

[Tapatio]

For our needs solar is a necessity not an option. It would help to know how you plan to use your SMB.

[Scalf77]

I would say a silent generator is Solar. Depending on your usage model it may not work for you, but will most certainly give you more options. Expectations of charging from the alternator is not a good full time solution.The van alternator will never give your battery the best charge to keep it at is best health, In that case you will need a good Shore Power Charger and/or a Good Solar charger. You could also hook a alternator to Battery charger up, much like is one from sterling power. At some point and time you are going to want to make sure the batteries go through a good proper charge cycle.

Living in the PNW there are times it is pretty useless, but for a majority of my prime camping season, it will be all I need to make it day to day, without driving or being hooked up. That will also depend on your power usage model, if you plan on using a lot of power hungry equipment, you most likely will not be happy. The other thing is the efficiency of these panels is increasing every year, so a lot depends on when and what type of panels your friends had experience with.

At a minimum get it pre-wired for solar, once you better understand your usage , you can then see if solar will fit your needs.

-greg

[purana182]

Hey Everyone,

Thank you for all of this, good read regardless. And no need to tip toe, not going to hurt anyone's feelings here, tell me how it is.

Sounds like most of you want to know my use out of it to make a better call, so here goes.

I live in San Diego, CA. I have a family of 4, most of our camping will be thur-sunday excursions to remote camping spots with no hook ups or anything like that. Some times places Like Joshua Tree, Yosemite, Death Valley, etc etc. We usually would park the vehicle I think and not move it until it was time to pack up and go home. Usually its a park it, camp, hike, climb, bike, explore and enjoy where we are. Hopefully no need to leave.

My rig wont have a microwave, only a isotherm 130 fridge, the usual lights, propane furnace and hot water heater. I also am putting in a 400amp house battery storage. It will have 4 6volt house battery's underneath rather than the usual single 4D batter SMB comes with now.

So, while I think I get the usage of Solar, if my battery's will work for the 3 or 4 days I am gone, would I even need the solar? Can't I just work off my house battery's and deplete them as the trip goes on? And IF, IF they start to get low, then turn on the van or something like that. The way most of these read, to me, is that people use the solar to keep their battery's full at all times?

I also think, no matter what, if I do go with Solar I would go with Portable rather than roof hard mounted...?

Lastly, to clarify or take out of the equation, I am not debating the decisions based on cost. Not that money is of no concern. But if its worth it, I'll pay for it, and if its worth it, I'll probably go above and beyond and get the most efficient/powerful/expensive system I can get within limits of size/storage capabilities...


Okay, now what???????????????????????????????

[boywonder]

I think something that may get overestimated at times is the power/amp-hr capacity of the house batteries.

It doesn't take much to deplete them sometimes, and a 400ah battery setup has realistically 200ah of energy available for use before you start to worry about excessive discharging.

It sounds like your energy needs may be light since you won't be using a microwave but things still add up when you are camping. Running your fridge 24/7 will draw roughly 3 amps X 50% duty cycle x 24hrs=36 amp-hrs a day (YMMV).

The other thing that can be overestimated is the power out of a typical solar panel. My 130W panel in full sun overhead puts out maybe 8 amps, more typically 2-3 amps or less depending on the angle of the sun, clouds, etc. So let's say we average 3 amps for 10 hours per day that's only 30 amp-hours a day. If your house batteries were discharged to 50% of capacity (200ah), it would take 6+ days for the panel to top off the batteries assuming little to no additional current draw for a fridge, etc. The upside is that the solar system puts out something whenever it's sunny, or even bright outside, and over time this adds up.

You can see that with a typical 120-130W panel, on average it should put out enough power to run a typical fridge (roughly-YMMV).

You'll really see your needs and power usage when you go camping, so doing a pre-wire is probably a good idea if you don't go with a panel/controller right away.

[Waterski02]

I went with 100W on the roof as well. Given your intended usage I could see it benefitting your battery health, even it in only keeps up with your draw.

We typically drive, stay somewhere 2-3 days, drive again. On all but the cloudiest of days the solar panel brings our 3 Group 31 house batteries back to float charge by lunch time to early afternoon.

Assuming normal loads, which is fridge, some lights at night, and stereo for 3-5 hours a day, and partial sun, I should be able to go 5 days without needing to start the van and still have my battery bank above 50%.

As others have said, at the very least prewire for it.

[photographix]

I put 280 Watts worth of panels and a controller in last spring. Did it myself, and I really wish the van had come with a pre-wire for solar. Routing the wiring was the most troublesome part of the install. I agree that having the pre-wire done would be money well spent, even if you don't go with solar now.

I can't add much more to what others have already said, and have said well. My experiences with having solar support their statements.

I wouldn't have an SMB, or any camper for that matter, without solar. It never needs gasoline like a generator, works all the time even in overcast conditions, and is absolutely silent. If you get a good solar setup, you'll probably never need to consider getting a generator.

Plus, if you park the van in the sun between trips, you won't have to worry about plugging your van into an outlet to keep the batteries up.

[REF]

Purana182-I agree with most of what's been said already, and ya, your buddies with the solar companies may not own RV's, or if they do, run generators, it's not the same as running a house where you need a whole array to run the thing. We bought our SMB used about 9 yrs ago now, the original owner didn't wire it for solar, granted in '03, the technology and the efficiency to cost ratio was not what it is today (and it will only get better) And after several frustrating years of fighting dead batteries, having to replace those expensive unmaintained 4D batteries and getting woken up at 3 am by the CO2 detector chirping away because the house charge was too low, we finally added solar, and as mentioned already, I wouldn't build out any RV without it now. We don't draw a big load, no micro, and I use the van regularly for work and play, I learned that with all these systems installed there are always small phantom draws on the batteries, our 145w solar panel keeps things topped off nicely when parked for several days on end, whether that's in front of the house or out in the middle of the desert. You mentioned a portable system, while many have them and like them (Zamp), there is the issue of storage and space is at a premium, plus having to take the time to dig it out, set it up, then if left unattended, it may take a walk. I love having ours roof mounted, always out, and secured, less to deal with and worry about. Like others have said, at the very minimum wire for it, but in my and many others opinions, adding solar is one up front expense that you will never regret spending money on.

[Viva]

One thing (that may not even be an issue) is that I would ask what size wire is used for a pre-wire. I find that there seems to be a tendency for too small a wire.

If you are running single 100 watt panels in parallel (by that I mean any number of 100 watt panels, but not in series pairs), they will be around 17.5-18.5 volts. So the wire you have coming down from the roof combiner box will be carrying ~18 volts times whatever amperage your panels put out (say max 18 amps for 300 watts), and you want to calculate the voltage drop for that length cable (it might be around 8' or more one-way to get from PH top, allowing a couple feet for top raising, and down to your controller).

For voltage drop you have to add each leg (each leg will have some voltage drop), and all together I like to see 1.x % and no more. Sure, it will work with 3% or 5% but you are basically throwing away power, and with a van you can't always just throw more panels at it to make up for that.

This is a roundabout way of saying that I wouldn't want to be pre-wired with #10 cable, and then find out that #6 or #2 is what I wanted to keep voltage drop down. Maybe they could pull a line and not clamp it at all and you could then use it to pull your wire through once you had your system planned out?

If you run series pairs, the higher voltage makes smaller wire okay, but then you can't have odd numbers of panels, and plus shade on one of the pair will affect the other. That can be undesireable.

Upshot is, my guess is that many pre-wire jobs end up with cable that induces more voltage drop that you would really want. I may be wrong though, and if so, then I'm glad to hear it.

[Chance]

Originally Posted by Viva

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Third, there is no silent generator. Oh do I wish there were, because then every time I go camping or boondocking I wouldn't have to spend 50% of the time listening to the "quiet" Hondas of the people camped nearby (and not all that nearby either as the sound carries). Also, you have to store the generator (which then means you ahve to leave something else at home), plus carry fuel for it. Not that there is no place for a generator (and some people are considerate), but there is no "silent" generator.

......cut.....

Fuel cell power generators exist, but are expensive. If you do a search you'll find many new reports on relatively new equipment. With any luck you'll soon get your wish for silent electrical generation other than solar. Costs still seem too high.

[daveb]

Yep, EFOY produces some stuff a few members have posted about them but I never saw a reply on real time operations of the units. Like solar, so many people think of these like an ultimate power solution in powering an RV when in fact they are designed to supply a light charge to a battery bank. It's the battery bank size that supplies the standard demands of a small RV like a SMB in most situations. You just can't run things for lengthy times like 110AC hot plates, hair driers of space heaters and the like due to the power they consume.
One advantage of a fuel cell is it works W/O the needs of any light, is quiet, and the fuel requirements aren't like those of a gas generator. However a 3000 watt load is out of the reach of a small fuel cell just like solar.
For the money a +/- 200 watt solar array coupled with an adequate battery bank provides a good balance for a Sportsmobilers needs. I just run the engine to supplement the load requirements when running my microwave which pulls about 80 amps @ 12vDC on high. If I use a lower setting, I can still warm something that needs only a minute or so to heat up with out running the engine. With my 400AH battery bank I still never reach 50% of discharge by morning and have plenty to spare throughout the night to power my Espar heater or a fantastic fan, the stereo, a DVD player and LED lights. My batteries are usually charged to full by 9am even in partial shade. I have 270 watts worth of solar on top of my van and enough room for a cargo pod. It's a good balance and works for me.