SOLAR or GENERATOR? One "SAVES" the environment and the other...?

[kscherzi]

I think it beyond 80% discharge or below 10.5 volts where serious damage starts to be done that affects battery life. Its better to avoid dropping that low but using 12.5 volts as the floor seems kind of excessively conservative.

[westcoastas]

Okay Lewster, now I'm confused. I should have consulted more with my dealer but at the time didn't know enough to question the efficiency of the converter. But what's confusing me is that the manual says the converter is a 7300 series converter. When I open the panel, there's a plastic pouch with a sticker that says it's a Parallax Power Supply Series 7300, Model 7355, 55 amp. But then there's another green sticker that says the power center has been retrofitted with a Progressive Dynamics converter. I don't know if that matters. So where do I go from here?

[lewster]

Originally Posted by westcoastas

Okay Lewster, now I'm confused. I should have consulted more with my dealer but at the time didn't know enough to question the efficiency of the converter. But what's confusing me is that the manual says the converter is a 7300 series converter. When I open the panel, there's a plastic pouch with a sticker that says it's a Parallax Power Supply Series 7300, Model 7355, 55 amp. But then there's another green sticker that says the power center has been retrofitted with a Progressive Dynamics converter. I don't know if that matters. So where do I go from here?

Yep! You DO have a PD-4655 conversion. I can tell by the new fuse block with the red LEDs on it. Given that fact your converter has been upgraded, my next question would be the amount of draw you are placing on those batteries, and how quickly they are being recharged.

Interstate batteries are NOT the highest quality (OK, here come the flames!!!!). They are the battery that I replace the most!! I have a pile of dead batteries at my shop and fully 85% are Interstates.

But regardless, if you deeply discharge ANY battery, they MUST be fully recharged almost immediately to prevent the leaching of sulfur from the electrolyte onto the lead plates ( a process called sulfation). In addition, it is not wise to continually draw a lead acid battery below 50% depth of discharge on a regular basis. This voltage level varies with different battery manufacturers; Lifeline AGM is 12.8-13.2VDC for 100% full and 12.2VDC for 50% discharge. IIRC, Interstates are 12.7VDC for 100% and 12.0-12.1VDC for 50% discharge.

If you have been exceeding the lower level regularly and have not been fully recharging immediately, you have damaged the batteries. Also, due to their very high level of internal resistance, they self-discharge rather rapidly; in the neighborhood of a month.....so 3 weeks left unconnected in the back of a truck would have probably seen them at 12VDC or less to start off.

I would have them tested at a reputable battery shop. See if they have the latest in battery capacity testing equipment.....a condutance meter. This device gives a very quick and accurate decision on battery condition without a load test or other older testing options.

If they are still under warranty, I would seek redress from the place of purchase, or any other Interstate dealer.

[ROBERTSUNRUS]

Originally Posted by lewster

Interstate batteries are NOT the highest quality (OK, here come the flames!!!!). They are the battery that I replace the most!! I have a pile of dead batteries at my shop and fully 85% are Interstates.

Hi, I agree that interstate batteries are not the best; My [cheap] Costco batteries have been as good or better than my Interstates were. If Interstate has the most batteries out there you obviously will have the most bad ones too. Sort-of like the Goodyear Marathons. [more tires, more failures]


Most Airstreams come with Interstates and Marathons, so most of the failures will be........ .......Interstates and Marathons.

[Foiled Again]

Lewster's advice is always great. He knows his stuff.

I do know that lots of electronic gadgets carry a phantom load. Every toaster and coffee maker now seems to have a clock timer. If you don't unplug them they use electricity 24/7, not just when you're toasting or brewing. Every microwave made has a clock, and if you have a built in one, it's impractical to unplug it. Even when your fridge is running on propane it has an exterior display - and an interior light that both use power. Have children with electronic gadgets they're recharging? Chase down those phantom loads and reduce them where you can.

LEDS do save a LOT of power. I converted most of my 2006 Airstream's lights to LED's. It does make a startling difference in brightness and electric usage. Also if you've got halogen bulbs they run HOT, they burn out fast and they are expensive to replace. LED's seem to last forever so all in all, they are a better bargain even in the short run. It might cost $300 to replace every bulb inside and outside, but since you don't use the running lights when you camp, why not just change the overhead lights and the ones in the bathroom. The ones in the closets and under the bed don't get used all that much anyway so you can do them as they fail. I like warm white, some prefer cool white. Try one of each before you commit.

Happy trails, and hope you find the source(s) of your problem.

Paula

[westcoastas]

Thank you Lewster very much and the others who chimed it - I really appreciate it! I should have read up more before I bought these batteries. Darn, about $300 spent inefficiently. Oh well, lesson learned.

Again, thanks again for all your time. Well, it's time to pack up and move on to a new address!

Jeff

[IanPoulin]

Returning to the OP position, the reason I would like to go Solar (still haven't pulled the trigger; maybe this fall) deals more with two factors:

o The (belief at least that) assurance of having availability of the battery power source in good health at any given time or situation; opening more boondock or camping options where possible.

o The ability to be in the wilderness and listen to the wilderness; not engines. There is nothing more calm to me than the sound of the wind through 100,000 pine trees at once.

[acstokes]

Returning to the OP position, the reason I would like to go Solar (still haven't pulled the trigger; maybe this fall) deals more with two factors:

o The (belief at least that) assurance of having availability of the battery power source in good health at any given time or situation; opening more boondock or camping options where possible.

o The ability to be in the wilderness and listen to the wilderness; not engines. There is nothing more calm to me than the sound of the wind through 100,000 pine trees at once.

I'd like to add one more advantage to this list:

-Convenience. You're not having to haul out the generator, hook it up, gas it up, unhookup, and stow it away.

[Goin camping]

Before I got solar panels and a big battery. I could get two days from my interstates. So I don't think you are that far off for what your system will deliver

[gandttimes]

All these scenarios of peacefully camping in the forest whilst your solar silently keeps all your toys operating is all fine and dandy until is rains constantly for 3 weeks in a row. Which is what happened to us this last November and January travelling through Oregon and Northern Cal.
Luckily the TV kept the charge up between campgrounds as the solar didn't have a chance.


George

[IanPoulin]

George - which is why you keep a genset as a backup - that or install a sailing wind vane as well. Usually when the sun is not available, wind js

[gandttimes]

Originally Posted by IanPoulin

George - which is why you keep a genset as a backup - that or install a sailing wind vane as well. Usually when the sun is not available, wind js

Have a generator. Didn't want to take it. Learned my lesson.


George

[McDave]

Some of you guys seem to know a lot more about this than I do, so I'll pose a question. Hopefully not too much of a hijack, since I think it's a valid part of the comparison between solar and generators. I have what is described on the box as a 2,000 watt Yamaha generator. However, in the instruction manual, it says the generator is capable of delivering 120 volts at 13.3 amps. Shouldn't they be selling this as a 1,600 watt generator?


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[Tincampers]

Probably 2000 watt surge and 1600 continuous.

[rmkrum]

Yep. Marketing speak. 1600 watts becomes 2000 in the hands of the sales department to compete with other manufacturers.

As an engineer, I really hate this kind of stuff.


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[switz]

The puffery also applies to solar panels. One sees the adds with a marketing claim of 100 watts. The reality is a good one may produce 75 watts at noon with the sun overhead. Cheaper units can produce at an even lower percentage of the marketing claim.

I have seen 575 watts reported by the TriStar 60 charge controller on a sunny day. There are eight AM Solar 100 watt panels on the roof. I was told that one should estimate solar production on our system as 5 amps per panel times the number of effective "sun" hours per day. So our solar system could be considered to create 5 x 8 x 6 hours or 240 amps into the battery array per day.

The new lithium iron phosphate batteries can bring a lot of power in a small package as they can safely use 85% of their amp hours, so a 300 amp battery system could provide 265 amp hours. It would have a 11.25" x 14.5" foot print and need about 11.5 inches in height for the wires and weigh about 84 pounds. That is less weight than one Lifeline 6CT6 Vdc 300-amp hour battery which weighs about 93 pounds and the pair would weigh about 186 pounds but provide a maximum of 150 amp hours.

We initially started our Airstream experience with the mated pair of Honda 2000 watt generator sets (could run the air conditioner in the 25FB) and had to run one every morning to bring the Interstate batteries to full charge for the next night of furnace operation at theOctober Balloon Festival at Albuquerque. The dealer installed 155 watt solar panel could not bring the two Interstate battery array up to full charge.

So when considering the off grid experience, full propane tanks, a well designed solar system and a backup generator allows for all eventualities to occur.

One needs to remember to install a switched outlet for each television so they are truly "off" as they draw power for the instant on feature or to let big brother eve's drop in the home (Sony can do that on their new models and perhaps can "see" like in Orwell's 1984).

[lewster]

Lou,

As you probably know, the difference in rated solar panel output and the actual observed output is basically the difference between the 'STC' (standard test conditions) rating and that which is seen at NOCT (normal operating cell temperatures).

The solar industry came up with a standard to rate all panels as an apples-to-apples comparison among the various panel manufacturers. Sort of like EPA mileage ratings! Just like one never sees the EPA rated mileage in normal driving, you never see the STC rated panel output either.

The set of conditions for STC ratings assume conditions that are not found in actual use, but are for lab testing. Things like cell operating temperatures, amount of solar radiance per sq. meter, light transmissivity thru the atmosphere, etc.

In real world settings, I have measured up to 92% of a panels rated output, but you can more realistically expect to see 60-80%, depending on sun angle, atmospheric conditions, air quality and panel surface temperature. The key is to design a solar charging system that meets your electrical requirements and fits your budget, and then have it installed by a knowledgeable and experienced tech, as you have done!

But as always........YMMV!

[Wayward]

Originally Posted by Ray Eklund

Describe "your special needs for either system", not criticizing another's specific needs.

Sometimes a "need" is but rationalization.

I grew up camping in a tent. I never "needed" them, but admit to a tinge of excess consumption when I bought an air mattress and single burner propane stove.

When married, my wife made it crystal clear that stove or no stove - sleeping on the ground in the rain was stone age.

I still have no idea what got into us when we bought the Airstream but soon realized my "need" for solar option was rationalization, trying to ease my lingering guilt over such an "aluminum footprint". I decided to embrace the freedom and enjoyment that an Airstream offers - a generator makes far more sense to me for the way we camp.

Camping is recreation. We "need" nothing because none of us need to camp. Primitive or otherwise.

I still "want" solar - it is cool.

[rmkrum]

Ditto. Wife camped on the ground on one memorable trip in the rain through the redwoods with three kids in a Volvo station wagon. Next trip was in a do it your self custom van with a real bed....


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[Ray Eklund]

BEFORE you plan on a Honda generator or a Solar Powered Airstream, consider some finer points of needing anything other than your "original factory batteries".

The factory batteries can be totally ruined by the RV Dealer who lets them die in the lot and uses some contraption to hook up to the deader than dead batteries to show it to a prospective customer. Ours were among those killed on the dealer's lot...not even a LED light would work. Did get the sealed batteries from the company, with a difference in price paid up, upon replacement.

Now that has been covered.

If you have an Airstream with the refrigerator fan... it will run most of the time in the desert Southwest... like Boulder City, Nevada at the Lake Meade campground. You will be running your Honda for 45 minutes if you are frugal in power use to keep in the 11.4v to 11.9v range. Generator running, 13.2v or 13.4v. A Solar Panel IS beneficial for those with running ceiling vent fans and the refrigerator fan. Eventually, if not connected to power, you will exhaust the batteries.

Although pulling the Honda out when taking showers, hair dryer is a real challenge in testing the will of the Honda... you can maintain reliable power for the exhaust fan over the cook top, ceiling vent fans and the refrigerator fan to cool the coils. Also any of the blinking or steady lights you find everywhere. LED or not. For reliable recharging... a Solar Panel or two will do the trick.

For a hair dryer... a Honda, unless you have some high dollar solar outfit covering your entire roof top of the trailer. Television... Honda.

I heard more pumped up Solar Stories than a human could endure after being camped in the desert for... five weeks this year. I do not know who or what to believe any more. Military grade??? Flexible??? Brands???

I just know not to stick a screw drive across the + and - terminals of a battery. That is about my limit of the Theory of Electricity. I want to flip a switch and something connected to the other end... works. That's it. Knowing amps, watts, recharge rates, volts, and static electricity are not in my vocabulary.

Pulling out the Honda and let it putter along will work and has some side benefits. Television and hair dryers.

Solar Power. Absolute easy sailing when off the grid with solar. But who to believe? One quote is $1500 and another is $900 for 150 watts and whatever gauge wires and black boxes attach to all of this stuff. Two RV dealers in the business.

I know how to operate the Honda. Fuel, On, turn gas cap to On... pull. 13.3 volts, at least.

Solar...? Maybe a booklet... "Solar Power Made Easy to Understand and Evaluate" when you want only to maintain a dependable supply of charge to your batteries and not be able to power up a space module for NASA.