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Old 04-18-2015, 07:17 AM   #57
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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!
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Old 04-18-2015, 10:34 AM   #58
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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.
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Old 04-18-2015, 07:30 PM   #59
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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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Old 04-21-2015, 09:51 PM   #60
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SOLAR has an advantage

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.
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Old 04-21-2015, 11:25 PM   #61
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A LED television doesn't require much power. Easily powered by a small inverter. Solar can supply plenty of recharge for losses incurred by a TV. Other than AC and microwave, batteries and solar can meet all other normal demands. My inverter even powers a power drill and a 5 gallon air compressor, probably not a high current tool like my circular and rip saw. Still looking for a generator that's not heavy and powers a 15,000 btu AC.
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Old 04-22-2015, 07:20 AM   #62
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Ray well said
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Old 05-01-2015, 04:28 PM   #63
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After camped at the Lake Meade Campsite out of Boulder City, Nevada for several weeks, not having solar is noticeable, compared to our less than optimum 2006 23 footer with maybe a factory installed 80 watt system. At least the solar panel did maintain a reliable recharging during the day of our minimum power usage after sunset. Mostly one bulb of light so my wife could read. My listening to the radio, IF reception was possible with the antenna that is standard with Airstreams AND the fan that cools the coils for the refrigerator. Taking a shower was out of the question, unless hooked up to the tow vehicle.

The Honda generator did provide powering these options at 45 minute run times to maintain the batteries. To even use minimum 12 volt power, we could not depend on the generator to provide a full charge for three or more days. The debate becomes the cost of solar versus the inconvenience of ten minutes to hook and unhook the generator.

When tent camping with 110v power at a camp site, we had the 110volt coffee pot sitting on the picnic table with an extension cord to the tent. In the morning we would plug the coffee pot into the extension cord from a window portal and presto... hot coffee. So, it is a very difficult decision to spend the money for a Solar System when our camping options use to be... this fresh coffee in the morning.

Am I now become jaded? It is still a struggle to find confidence in a RV Dealer and their sales pitch and cost varying faster than the DOW Jones Industrials. Eventually, this walking the line will come to a conclusion. Lewster is one person I have confidence in his opinion. Just a reliable output for our frugal needs, plus a percentage to keep our batteries charged.
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Old 05-01-2015, 05:15 PM   #64
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During the day I can run both fantastic fans and still see a decent charge going into the batteries. This assumes full sun. But if it's not sunny probably not running the fans anyway. Not familiar with a refrigerator fan, mine doesn't have one I think. It's odd how your battery runs dry with so little being used.

I don't own a generator so making the solar decision was a littler easier. Sounds like solar for you is a matter of more convenience. A nice byproduct of solar is the batteries are always fully charged before every camping trip.
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Old 05-02-2015, 12:00 PM   #65
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AGM Interstate Batteries versus Original Standard Equipment

kscherzi: It's odd how your battery runs dry with so little being used.
*****
We have a volt meter and maybe that is what catches my attention. When the Honda is idling, 13.2v to 13.4 from the 20 amp side of it. I will be getting the attachment to the 26 amp connection before this next camping trip. No one has mentioned if there is a difference as far as the Interstate Marine AGM sealed battery recharge and performance, either way. Someone might know and explain how this works.

When the generator is disconnected or shut down, I am looking at 11.8v to 11.3v after using battery power. Our lights and fans are not affected by this voltage, but the water pump runs slower while on battery. With the Honda, the water pump sounds totally different and runs at a higher RPM.

Without a volt meter reading, maybe I am just being to cautious not to run the batteries down below 11.0 volts.

Am I being too concerned, or not? The original batteries, after being charged with the Honda, would be in the 9.2v to 9.5v by morning, not really using them during the evenings. Each day I recorded the consistent drop in voltage with minimal use.

Interstate Batteries determined a possible weak/dead cell was draining both. For a modest extra cost I was given Marine AGM sealed batteries and am currently using them.

If they are 12.0 volt and I am in the 12.3 to 12.8 volt range... is that optimum? When should I be hooking up the Honda and charge the batteries?

I have read on the Forum that the Tow Vehicle connection does not do much as far as charging the trailer's batteries. Then get the idea that even the Honda directly connected to the trailer requires time... Somewhere there is a basic understanding of what is accurate information. I sure am not the source for anything concerning the Honda, the Tow vehicle and a volt range of the trailer batteries that are acceptable before a charge.

Any help out there?
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Old 05-02-2015, 11:30 PM   #66
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What I've heard about lead acid batteries is they should be kept as fully charged as possible all the time for longest life. Keeping voltage above 12 volts (approx 50% charge) at all time is most desirable. Somewhere on the internet (and it never lies) I read that going below 10.5 volts will likely result in permanent damage. Especially if not immediately recharged. It's takes my trailer about 3 days of no sun from full charge to drop below 50% in normal use (lights, TV, radio, heater, shower). In full sun the solar system will do a full recharge in about 4 hours.

If your batteries are reading 9 volts they're likely done for. Check AM Solar online for cost of their self install solar packages. Start with at least 200 watts. If you don't feel comfortable doing this then a couple thousand dollars to have someone qualified put their packaged system into your trailer seems a sensible starting point for a budget of such a project. Don't forget, you might be able to get a federal tax credit for the solar system if your trailer qualifies.
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Old 05-03-2015, 07:35 AM   #67
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I was involved in the golf cart business for a long time - 10,000 golf cars per year new, about the same used. About 60% were electric - four 12v deep cycle lead acid batteries. Which are the same as in the AS trailers we all have today. We kept these batteries alive for up to four years and sometimes longer by essentially taking them down to zero with a discharge machine every fall (we operated our business in the north) and then immediately charging them back up again to full charge which is anywhere between 12.3 and 14v depending on age and the meter one is using. Then in the spring, back on a new charge and out to play golf all season. These needed to be watered so the level had to be checked weekly and properly filled.

If the battery goes down below the 9 volt level it probably will not operate anything in your unit, but can be brought back to life if it has not frozen, once frozen they are done for.

Now as a caveat to all this, lead acid deep cycle batteries like to be charged, love to be charged, so the more one charges them the better. Drain them and charge them, they last a long time.

That's about it, pretty simple, keep in mind we had responsibility for over 52,000 batteries a year so there was a little experience and history to go by here. The technology has not changed, the AGI battery right now is far superior and in my (our) opinion well worth the money, we have them in our AS.
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Old 05-03-2015, 07:34 PM   #68
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OK. I am denser than the Universe BEFORE the Big Bang when it comes to electricity in the trailer.

On home 120volt the trailer voltage meter is reading 13.6 volts. If it is a 12 volt system, why does the system read 13.6 volts?

If I disconnect the 120 volt from the outlet, I am reading 13.3 volts.

How can 12 volt batteries display MORE than 12 volts? Nothing is operating or turned on, just reading the meter.

Do 12 volt batteries like mine, AGM Marine Interstate, discharge 13.3 volts and then after using them... drop below 12 volts and, from my first watching voltages when off the grid, the voltages seem to hover in the 11.3 to 11.5 range with the refrigerator cooling fan usually running and maybe one LED light, and occasionally the water pump running for filling drinking water bottles and modest use, otherwise.

paiceman and kscherzi... Can you explain to an ignorant 12 volt person how this all works? Is an IGA battery superior to an AGM Marine battery? Interstate sales people said this was the best they had... to offer me. Was I a Stooge in this deal, too?
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Old 05-03-2015, 08:10 PM   #69
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OK. I am denser than the Universe BEFORE the Big Bang when it comes to electricity in the trailer.

On home 120volt the trailer voltage meter is reading 13.6 volts. If it is a 12 volt system, why does the system read 13.6 volts?

If I disconnect the 120 volt from the outlet, I am reading 13.3 volts.

How can 12 volt batteries display MORE than 12 volts? Nothing is operating or turned on, just reading the meter.

Do 12 volt batteries like mine, AGM Marine Interstate, discharge 13.3 volts and then after using them... drop below 12 volts and, from my first watching voltages when off the grid, the voltages seem to hover in the 11.3 to 11.5 range with the refrigerator cooling fan usually running and maybe one LED light, and occasionally the water pump running for filling drinking water bottles and modest use, otherwise.

paiceman and kscherzi... Can you explain to an ignorant 12 volt person how this all works? Is an IGA battery superior to an AGM Marine battery? Interstate sales people said this was the best they had... to offer me. Was I a Stooge in this deal, too?
I'll take a shot at this:

FIrst of all... VOLTAGE is like water PRESSURE.
AMPERAGE is like GALLONS OF WATER.
WATTs is like GALLONS per minute AT a certain PRESSURE (i.e., it's a measure of WORK capability)

(A simple algebra equation explaning it is Volts times AMPs equals WATTS.
This is similar to 10 psi of water-pressure being applied to a 20 gallon container of water producing 2 gallons per minute at an average pressure of 2 psi. ( I made that example up as an illustration.)

Although we refer to the common auto battery as TWELVE volts...that's a NOMINAL value...it can hold 12...or 13.7... or 11.5 or... you get the picture... And when we re-charge it...we "pump" more than 12 volts into it (think of "speeding" up the recharge process... or blowing up a balloon... if a balloon has 12 psi in it..how can you charge it up MORE unless you put MORE than 12 psi into it?) TYPICALLY A 12 VOLT BATTERY IS ACTUALLY RECHARGED AT ALMOST 14 VOLTS. And as such, it will hold 13+ volts when completely charged. (the balloon is blown up tightly)

When the balloon is LESS than full...it may still have some air in it...but it will not expel it sufficiently to feel it very much. That is like a DIS-charged battery (say down around 10 or 11 volts.)

Get it? VOLTS is like PRESSURE. To FILL the battery with volts you must put MORE into it than it's NOMINAL rating.
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Old 05-03-2015, 08:10 PM   #70
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Originally Posted by Ray Eklund View Post
OK. I am denser than the Universe BEFORE the Big Bang when it comes to electricity in the trailer.

On home 120volt the trailer voltage meter is reading 13.6 volts. If it is a 12 volt system, why does the system read 13.6 volts?

If I disconnect the 120 volt from the outlet, I am reading 13.3 volts.

How can 12 volt batteries display MORE than 12 volts? Nothing is operating or turned on, just reading the meter.

Do 12 volt batteries like mine, AGM Marine Interstate, discharge 13.3 volts and then after using them... drop below 12 volts and, from my first watching voltages when off the grid, the voltages seem to hover in the 11.3 to 11.5 range with the refrigerator cooling fan usually running and maybe one LED light, and occasionally the water pump running for filling drinking water bottles and modest use, otherwise.

paiceman and kscherzi... Can you explain to an ignorant 12 volt person how this all works? Is an IGA battery superior to an AGM Marine battery? Interstate sales people said this was the best they had... to offer me. Was I a Stooge in this deal, too?
Ray,

Do you have your original Parallax converter? If so, the reading that you are seeing (13.6VDC) is the only voltage that your converter puts into the batteries. 12VDC is called the 'nominal' rating. Almost any '12VDC' battery that actually measures 12.0VDC is well on it's way to complete discharge. Depending on the battery manufacturer specifications, a 'full' battery with 100% charge can vary from 12.7VDC (Interstate liquid cells) up to 13.2-13.4VDC (Lifeline AGM batteries).

There are definite and specific differences in battery construction and the amount of lead that is used in their manufacture. I have weighed different batteries within the same group category and have seen marked in the weight of the batteries, even though they are 'rated' to be the same. Take a group 27 battery. The Interstate liquid lead acid battery is rated at 100 amp/hours of capacity at the industry standard 20 hour discharge rate. A Lifeline AGM group 27 battery is also rated at 100 amp/hours.

The Interstate weighs about 50 lbs, where the Lifeline weighs 65 lbs. Why the difference? It's in the amount of lead that is used in the battery construction. More lead gives you more usable energy!

The other problem is the huge amount of bull pucky that most folks in the battery industry throw at the customers. It's almost as bad as buying a used car!!!!! One of the biggest myths is the 'deep cycle/marine' battery. These are made for starting an outboard engine AND for operating running lights and instruments on a boat. They are a hybrid; neither true deep cycle nor true starting battery.

You need a true DEEP CYCLE battery for RV use, as these will show the most capacity for the slow, controlled discharge that is prevalent in RVs. I generally use Lifeline batteries exclusively in my solar installations, as they have proven themselves over time to have the most energy density and longevity in the AGM battery category. I won't get into the new lithium cells here, but they far exceed the capacities and life span of AGMs at about 1/3 the weight and twice the price. Over the long run (10-15 year anticipated life span), they prove themselves to be the best battery value, but they are a significant up-front cost.

Back to your problem: your batteries should not be discharged much below 50% (12.1 VDC for Interstates) on a regular basis. 11.3-11.5VDC is getting very close to a totally dead battery. The more you discharge to this extremely low level, the fewer charge cycles your battery will have.

More importantly, your 13.6VDC converter is also ruining your batteries in the following way: ALL lead acid deep cycle batteries require 3 stage charging at voltage set-points formulated by the individual battery manufacturers. For Lifelines (the batteries I use most) they require a BULK charge of 14.2-14.4 VDC, an ABSORPTION charge of 14.2-14.4 VDC and a FLOAT charge of 13.2-13.4VDC. (These are measured at 77ºF).

As you can see from the charge levels above, 13.6VDc will never completely fill your batteries and if they DO get fully charged, they will be continually OVERCHARGED because they will never see the 13.2. VDC that they require as a maintenance charge.

Unfortunately, battery charging and maintenance is a technical subject that can become rather complex. Some folks just ignore all of the above and buy the cheapest batteries they can find and replace them often. Others spend thousands of dollars on solar, lithium batteries and sophisticated charging systems because they never want to think about their battery health, don't want to deal with any type of maintenance issues and want to be certain that they can fully depend on their batteries and charging systems. It all depends on what you want from your camping experience and what kind of reliability you want from your battery system.
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