Solar and Generators

[Melvin P. Thorpe]

Factory will install (2) 50W solar panels, good idea?

Yamaha and Honda compete for RV market. Any experience with Yamaha?

[davidz71]

How much dinero they talking about?

[Melvin P. Thorpe]

Waiting on the quote sheet now. Should have it by Monday and I will post what I find.

[femuse]

Honda.

As the owners of a 1000i & 3000i, I don't think anything else comes close.
If you camp alone, far from anybody else, and don't mind the noise: Yamaha. I suppose it's cheaper.
If you do not want to disturb your neighbors, do not like noise: get a Honda. Yamaha try to compare their specs to Honda's, things like Db level::::: BUT::::: they don't say Db at what distance. They are very vague about that.
We had the old Honda 1000, bought it used several years ago, used it for several years, sold it for more than we paid for it.

[RoadKingMoe]

If you're lookin' at a new production trailer, with two of the Interstate Battery SRM27 (85AH each, 17 hours at a 5A discharge), you'll usually be able to get 'em up to 90% charge each day (that last 10% takes longer) and you don't wanna run them below 50%, so you have 40% or 68AH to play with. On a new trailer, the day's use might go like this (if you only turn the water heater on a coupla hours a day):

06AH LP Dectector
06AH Refrigerator Circuit Board
12AH Refrigerator Gas Solenoid 50% duty cycle
02AH Water Heater Gas Solenoid X 2 hours/day use
10AH 1 30W dual-tube flourescent light X 4 hours
05AH 1 30W dual-tube flourescent light kitchen X 2 hours
06AH Bathroom/shower lights & vent fan X 1 hour
04AH Range hood vent fan & light X 1 hr cooking
01AH 6A water pump X 10 minutes (16 gallons at medium flow)
16AH TV + Antenna Amp or Sat Receiver X 3 hours
-----
68AH = 40% X 170AH

And if it's warm or cool and you want to use the Fantastic Vent or furnace, you don't have any capacity left for that.

Horizontally mounted solar panels give about 1/6-1/4 of their peak wattage rating as average AH each day. So two 50W panels would only get you about 17-25AH per day... make that SUNNY day. That will barely make up for running a Fantastic Vent during daylight to offset the heat gain of having to park in the sun for solar. Of course if you park in the desert and have to run the fan anyway during the daylight hours, two 50W panels would do that much.

Now if you run a quiet little Honda generator 4 hours a day from 5-9 or 6-10PM each evening, you're only left with the following to come out of the batteries over 20 hours:

10AH LP Dectector & Refrigerator Circuit Board
10AH Refrigerator Gas Solenoid 50% duty cycle
------
20AH

So they can now provide:
48AH Fantastic Vent on medium for 20 hours OR
48AH 7.5A furnace about 1/3 average duty cycle for 20 hours

With the generator running, you don't have to worry as much about how many lights are on, you can watch another hour of TV, use the microwave oven and other 120VAC appliances such as the vacuum cleaner, use a "real" 120VAC air compressor to air up the tires, and charge the batteries in the notebook computer, cell phone, FRS radios, PDA, rechargable razor, etc for use when the generator ISN'T running. The best thing about the generator is that it can deliver power through the converter directly when you're using it... so you don't have to cycle the batteries as deeply, unless you're using the Fantastic Vent or furnace all day.

If you're gonna depend on solar, you need AT LEAST five times your heaviest daily amp-hour usage in battery capacity. 2.5 times you don't use (50%), 1 time for the day you're using (20%), 1 time for a backup for a rainy day(20%), and .5 time (10%) for that last bit of charge you won't have time to finish. If we aren't going to camp when we need the fan or furnace and just need 68AH, then three 115AH Trojan 12V batteries would do it. But if we're gonna be using fan or furnace, for 116AH/day, we'd need five of those batteries.

You also need at least 5 watts of solar panel for every amp-hour of your heaviest daily usage to be able to make up for that rainy day in the following two sunny days. If we aren't going to camp when we need the fan or furnace and just need 68AH, then three 110W-120W panels could do that except perhaps in early Spring or late Fall. But if we're gonna be using fan or furnace, for 116AH/day, we'd need five of those panels.

That system would only provide one day backup, so you'd need a generator anyway.

I'd skip the panels and spend the money on a generator. Get two so you can parallel them and have air-conditioning too. But I'd also see if Airstream would install a couple of those Trojan 115AH 27TMH batteries, or if two of the 1/4" longer 130AH 31XHS batteries will fit.

Oh yeah... I forgot the phantom load of keeping the radio powered and remembering its programming... add another 6AH/day for that and we have a total of 73AH/day.

These new trailers aren't like the vintage ones that had no "phantom loads." On their best day, two 50W panels will power just the LP detector and refrigerator for 24 hours.

[Pick]

Great post Maurice. It seems as though we have taken a step back, energy wise with these new trailers, with the refridgerators and water heaters. Why are these so complicated now? I installed a new water heater last spring, (10 gallon Atwood) and it has no circuit boards. My propane water heater in my house has no electrical connections either. Not being familiar with these newer RV features, what is the purpose for the circuit board and solenoid, safety, convenience?

[Silvertwinkie]

That is pretty good info Maurice. Do you know of a generator that would be small enought to fit in the storage compartment of a Bambi? Most of the units I have looked at are pretty large or larger than I can deal with.

Worse is that the Bambi has zero flourescent lighting. All conventional bulbs. I know the car can charge the battery and I have a 140amp alternator in my tow vehicle. From the look of it, the the solar panels don't seem worth the bother, nor does an extra generator since I could just start my car and at idle it still kicks out between 75-85amps and for an hour that would be better? I got a 23 gallon tank in that car, so more than enough to run several hours if needed. Granted it would charge more slowly, but how much more slowly, I don't know.

What do you think?

Eric

[Silvertwinkie]

Just came across this:

http://www.airforums.com/forum...8915#post28915

Still wonder though if charging my batt w/ the cars alt would be signigicantly slower than connnecting one of these gens to the Bambi.

They are the smallest things I have ever seen. Also was wondering if 2 of the 2000 set in parallel would be able to only power the roof A/C unit alone.

Eric

[RoadKingMoe]

I'm not sure why.... smog? safety? (both related to a pilot light)

I'm not familiar with the Bambi compartment, but I do know that you can tip the Honda over to get it through a compartment door and then stand it back up because of the sealing gas cap.

Eric, check your wire from the car to it's plug. It's may be fused at 20A because it's 12 gauge wire. No point in going larger on the tow vehicle because that's what it is in the trailer.

One thing you need to be careful about is leaving the trailer plugged in when the car is off... unless you've put a relay in the power line that shuts that line off unless the tow vehicle ignition switch is in the "Run" position. The towing package on my truck came with such a relay, so you can stay hooked up with no threat of draining the tow vehicle's starting battery.

What matters for charge speed is how much voltage it's putting out at idle. Take a multimeter to it and find out. I've never had to find out myself, but I've heard guys complain that the battery still wasn't charged very well after 4-5 hours of driving. Guess it depends on your vehicle's voltage. Those "isolator" diodes (rather than the relay mentioned above) also hurt because they drop about half a volt.

Idling is hard on a big engine. Even with EFI it's running richer than with normal operation. It isn't generating much heat either so the cylinders are colder and the extra fuel tends to collect on them wash the oil off them. I wouldn't do that to my engine.

Oh yeah... don't confuse those EU1000s on Ebay with EU2000s.

One EU2000 owner scanned his Owners Manual and put it online.

Dick, I probably wouldn't continue to use the 11,000 btu on one 2000 if the compressor is starting slowly. That means the high starting current is going through the windings longer and getting them hotter. The truck camper crowd reports that one 2000 does fine with a 7,000 btu AC.

When it comes to charging with the generator, the time that requires depends on the converter. A 3-stage Inteli-Power w/Charge Wizard at 14.4V will faster than a 13.8V Magnetek, be they powered by a generator or by the power company.

I strongly suspect that even with running one or more generators for 4 hours, I'm going to want to replace the Magnetek with an IPw/CW.

But the only way to know for sure is with a good amp-hour meter like the Link 10. That's going to be my next purchase after the generators, probably followed by the Intelli-Power. When these batteries wear out, I'll go with much larger capacity ones in Group 27 size to fit my internal compartments.

Hope this helps.

[femuse]

Maurice

I'll go with much larger capacity ones in Group 27 size to fit my internal compartments.

We want to replace (some day) the #27 by #29. I see you are always talking about #27 or #31.
Is there a reason not to consider the #29? (the 31 won't fit in ours)
As an example - Interstate batteries:

SRM-27 Dim. (in): 12.75 x 6.75 x 9.5 Weight: 53 lbs RC: 160 minutes

SRM-29 Dim. (in): 13 x 6.75 x 10 Weight: 61 lbs RC: 210 minutes

I know that Trojan does not make a #29. Do you think then that a #27 Trojan is a better bet than an Interstate #29?
We are keeping what we have for now, but are following all that for the future.

[RoadKingMoe]

The problem is height. Because of the hinge on the compartment, it's more limited moving the batteries in and out than when they're fully in the compartment. I figure I can get about 1/4" more height than my 9.5" SRM27s, but that's about it. I don't think the 10" of a 29 would clear. And the SRM29 is only about 105AH. The nice thing about the 130AH 31XHS is the 9.5" height. Whether the extra 1/4" of length will fit is the question... it's gonna be close, but having a piece of 1/4" plywood under them may help get them in or out.

[femuse]

OK,
I see now that the 31XHS is only 9 1/2 high. I wish they standerdized those sizes.
If know that if one day you try to fit the #31, you will post your results and we can benefit from your experience. Hopefully, I plan to get a few years from my current set-up.
The 1/4 in plywood sounds like a good idea as it seems there will be enough height.
At first glance, it looks like the length is no problem. I should measure that carefully someday.

Thanks

[RoadKingMoe]

Originally posted by femuse
Hopefully, I plan to get a few years from my current set-up.

I understand. It's hard to spend this much money on a new trailer and have to replace inadequate components, but Airstreams have traditionally been made for elderly folks staying in full hookup campgrounds with an occasional overnight at Wal-Mart, not for semi-serious boondocking.

1. The provided batteries are inadequate. No trailer should have only one battery if boondocking is a possibility, and a big (for Airstream) luxury rig with a 9.8A furnance and TWELVE double-tube flourescent lights, should have four! Not only do they fall short here, but they use less capable batteries for the size.

2. The single-voltage converters are inadequate for good battery charging and not good with a 13.8V float voltage.

3. Airstreams are not good for use with inverters large enough to power the microwave, and part of that is insufficient batteries to handle the huge current of such an inverter. Then there's the wiring issue. If you wanted to replace the converter with something like a ProSine 2000 with integrated 3-stage charger and transfer switch, and use its "power sharing" feature, you want that to be as close to the batteries as possible because of the huge currents between the inverter and batteries that are going to require large gauge cables for the huge currents.

But that means you have to run heavy (for AC... 8 AWG or preferably 6AWG) cable from the end of the trailer cord up in the bedroom overhead in the rear of the trailer, all the way up to the front of the trailer to the transfer switch, then all the way back to the circuit breaker panel in the bedroom overhead cabinet.

4. Their solar prewire is inadequate for meaningful solar use given the way they route it. On my trailer, that's over 40 feet of only 10 gauge wire so to keep the voltage drop down to something reasonable, it means it can only support maybe 5 amps max.

5. The curved roof doesn't support many panels without them being obvious and ugly, not to mention visible to thieves. You'd be surprised how little linear length is left for panels even on a 34 if there are skylights in addition to the two vents and the AC. There are two spaces but what what I can see they aren't long enough for Kyocera KC120 panels... maybe Shell SM110 panels but even their current is more than the prewire can handle without significant voltage drop unless you wire them in series for 24 volts and use a SB6024 controller to step the voltage back down to 12V.

I've just come to the conclusion that a generator is the best solution boondocking with a late model Airstream. It eliminates the need for a large inverter or for solar, areas where Airstreams fall short. And while they're a more expensive solution that won't last as long, two 27TMH batteries that fit in the compartments will give the capacity of two T105 6V golf cart batteries.

Whew! Glad to get that off my chest!

[femuse]

OK, but:

I see the difference between power consumption in older vs recent AS.
In our 1974, with modern fridge on gas, no recharged of battery from truck (have to set this up soon), we boondocked last year for one full week with 1 battery. We used the 1000i a few times for microwave & coffee. Have a Power Pack for the laptop, recharge it while driving from cigarette lighter.

But, we are old pro at power misering (?) : We have replaced all the bulbs with 5w automotive bulbs. Arranged the switches so we can use 1, 2, or 5 bulbs (old AS have 3 position switches, and we are going to use those right away on this one).
We had AC on our 1971, tried it once to see if it worked. Never used it (even in TN mid July).
We are out of the trailer during the day, at night we open most of the windows. No shaded campsites with a brook for us either. That one week last year was beween shows, VT, NH to ME: WalMart & Sam's Club. Other times, it's fairgrounds or horse pastures. We are tough.

The new trailer is a 1990. We are putting a 2nd battery. We have ruled out golf cart batteries & solar. Mike is even dreaming about mounting the 3000i under the truck so we can use it more often. Over killed. The 1000 does a great job.

While on the topic of energy comsumption, I posted these earlier, with no luck. I hope you may have the same set up and can help us:

1_The book mentions that the 2 ceiling lights in the kitchen/living room operate with wall switch (OK), and the diagram shows an extra switch at the fixtures themselves.
New mystery: the front light (the one with the fan), does not have a that extra switch.
BUT: the other one has a switch. It is wired, but doesn't do anything. Any idea ?

2_The bathroom light (vanity) has a high/low switch. The dealer told us that the low is not supposed to be doing anything. Only worked on high setting. ??? We will have to get it to work on low. Don't know if it was working originally. Is there a special trick at pulling the switches of the wall without damaging them?

3_We discovered 2 fluorescent tubes hidden over sinks (kitchen & bathroom). Cannot find a switch for those. Are they original ?

Glad to get that off my chest!

That's OK, go ahead. I save anything that looks of interest, even about stuff we don't need now, but could use in the future.

[RoadKingMoe]

I don't think I can help you, but I'll try. Most of our interior lights are flourescent, except for the reading lights in the overhead cabinets over the couch and bed, the wall sconces just inside the door and on each side of the bed, and the chandelier over the dinette.

All our flourescents have switches on them. There are two double tube flourescents fixtures in the living room next to the Fantastic Vent. The one closest to the vent gets its power from a wall switch on the back of the dinette as you come in the door. The idea is to leave the switch on that flourescent on all the time, and switch it at the door. If it accidentally gets switched off at the light, the switch by the door is useless. The one next to that one is just wired hot like most of the others in the trailer and is turned on and off at the light.

We also have two double tube flourescents over the bathroom vanity mirror. Both, as well as an incandescent light in the shower, get their power from one wall switch next to the sink. Both also have switches on the fixture and you can turn the left one (or the right one) off at the fixture, for example, to conserve power when boondocking.

We also have a double tube flourescent over the bed that gets its power from a wall switch. It too must be left in the on position for the wall switch to function.

Other than that, the four double-tubes in the kitchen (two in the ceiling, one over the appliance garage and one over the sink), the two in the dressing area, and the one in the couch overhead cabinet, must be turned on and off at the light fixture, as is the case with the tungsten reading lights and sconces. The chandelier over the dinette is on an electronic dimmer switch on the back of the dinette by the door.

Maybe you can dig some useful info out of that.

[Melvin P. Thorpe]

Thanks for all the good information, I guess I'll just get one panel so it keeps the batteries charged while in the storage lot. Let me know if I am looking at this wrong but I think that with one panel it should keep the battries charged instead of having them go dead and then charging them up before we go RV'ing.

What do you think?

[davidz71]

Melvin, I'm a fan of solar and have just the 5 watt Solargizer maintaining my 2 Delco Voyager grp. 27 batteries when boondocking. I am a powermizer just like femuse and I have never had a problem. I have thought about two 50 watt panels, maybe two 75 watt panels or one single 120 watt panel. The more I think about what I want to do, (and the more I read from Maurice) I think a 75 watt panel supplemented with a generator should cover all my boondocking situations. You can't go wrong with a solar panel that keeps the batteries charged especially if you are dealing with phantom loads. I guess I get away with just the 5 watt because I do not use more than one or two lights at a time and not for long periods of time. I also do not use the water pump but for a short period of time during a 2-4 day period. This will probably change within the next year. Also, the batteries have 3-4 days to fully charge while I am away before the next hunting weekend.

Femuse, my wall switch controls the circuit over the sink. I have a single bulb fixture mounted overhead between the stove and sink. I have a double bulb fixture mounted overhead just to the right of the sink. Powermizer that I am, only the single unit over the Nutone unit by the stove is turned on when the switch is on. If I need additional light, the others are turned on while at the sink. This way, when I enter the trailer at night, a single bulb is turned on and that gives me plenty of light to do what I need to do. The lights by the fan come on only when I need additional light to look at maps or maybe a card game with the guys (gotta keep your eyes open when playing with them).

[RoadKingMoe]

I'd think a 50W panel should keep up with the LP detector and battery self-discharge in a storage lot.

[femuse]

Maurice:

Maybe you can dig some useful info out of that.

What I learned is: somewhere between 1990 & 2001 they made some big changes in the electrical system. The only thing I recognise is the wall light by the door.
We were stunned by the amount of light they use in a 1990 vs a 1974. It's a good thing we didn't go for a later model.

What we find very ennoying is the book is about only 50% acurate on most everything described.
To know how a specific model/year is set up help track down malfunctions or modifications.
Thanks for the info, I am sure it will help somebody in this never ending quest: "where in the world is the.......in my trailer?"

[Melvin P. Thorpe]

Well it looks like I can get the Safari in a covered area of the storage facility so there goes my theory about having solar to keep everything charged while waiting for the next trip.

I take it that the master switch does not turn off the propane detector and there are some other small draws on the Battery. Do you suggest completely disconnecting the batteries while stored? The new Safari has 2 batteries FYI.

Also, it seems like 2 Honda U2000's are the way to go because they are easier to move around for us old guys. Used to have a strong back and a weak mind, oh for the good old days.