RE: batteries
but it is my belief and experience that generally, two 6's are more durable than two 12's.
The problem is that there is no objective support for such a conclusion.
As with the discussion about brands and such, nope. sorry. the issue isn't there, either.
Of course, if you do have some decent data, specification, or measure that shows 6v is inherently longer lasting than 12v or something, I'd love to see it. I've been searching for years for such information and so far all I have found is some folks on these forums who have their minds set on some myth they cannot support in an objective way. But repeated empty assertion, no matter how strident, does not mean the assertion is generally correct.
If you are looking to buy batteries, go by price, specification, warranty, and retailer support. If you want best service from your batteries, pay attention to proper use and maintenace. If you want to fuss and fiddle and spin your wheels, then, by all means, get into brand names and voltages and marketing terms like "deep cycle battery" that no one can define in terms of you can really measure.
RE: My Battery Amp Hours
Figure 10 usable watt hours per pound of battery.
Don't fool yourself into thinking you can calculate anything closer than 20% as the temperature, cycle to cycle variances, use profile, age and other factors can influence battery capacity that much.
The only way to really tell if you have enough battery is to experiment and learn through experience.
RE: 6 volt vs 12 volt batteriew
The energy from your batteries depends upon weight, not voltage. Figure about 10 watt hours usable energy per pound. It is energy you need from batteries, not amp hours. Energy is the product of amp hours and voltage.
There is no advantage in typical RV service of 6v in series vs 12v parallel other than the fact that a T105 is a bigger battery than a typical group 27 (which is bigger than the group 24 often found in B's)
With a healthy group 24 in a B, you should not have any problem going off grid for a day or two unless you like to watch movies or are otherwise profligate in your energy usage. A good rule of thumb is that one DVD movie needs nearly a full 100 AH 12v battery (200 AH 6v) to show. But for occasional furnace, lights to go to bed, water pump and so forth, you should have plenty of energy for a couple of days if your battery is healthy.
Another myth is about AGM's - if you go by code, they are subject to the same regulations as wet cells as far as battery box requirements and venting. They are nice batteries and have their benefits but they are also rather expensive.
Besides the fact that there is no objective definition of a golf cart battery that you can find reflected in spec sheets, there are no batteries for RV service that last long if deeply discharged. You should avoid taking any lead acid battery below 50% (12.2 volts after sitting unused for a while) if you want maximum life.
When it comes to the _great true deep cycle 6v golf cart myths_ - start looking for actual reputable and reliable measures to back up the claims. You will have a tough time finding it. Spec sheets and warranties will tell the tale if you listen.
RE: No Cal - Susanville - Canby RT 139 or 395?
395 has a 'rest area' about 1/2 hour north of Susanville. Restrooms and water, but scarcely any place to park!
Just north of that rest area is Ramhorn Springs BLM campground. See US 395 North for some photo galleries and ideas of spots along the route.
RE: Topping off batteries when storing off site
If the batteries are in good shape, the self discharge rate should be fairly low and a month or two in storage shouldn't be a significant factor. Do make sure they are fully and properly charged before storage, don't have any loads attached (like alarms or indicator lights in the trailer) and that the storage location is kept cool. Do make sure to put a decent charger on them after storage to get a good full charge back in place before using them.
It is always better to use a good storage maintainer on batteries that will both keep a top charge on them and do some things to inhibit sulfation. That gets more important as the batteries get older or the storage times get longer.
RE: airstream interstate
This is not a B topic, but if one wants to go to any of the Airstream sites you can find out all about Beatrice Foods and the weak frames. They were famous,
This was when Wally's Airstream tried to reduce frame weight in the late 60's just before being bought out by Beatrice.
The real problem with the longer Airstream trailer frames had more to do with vibration fatigue - just ask Andy at Inland RV (he has some good documentation on this).
I have bought a 31' that had been to Alaska more than once. It had the 'elephant ears' indicating the $2000 repair on the rear for this problem. I have another similar one that didn't have the problem because it wasn't beat so much and the tires and wheels were kept balanced.
But the Airstream B's, whether the Falcon based or the Sprinter based, are pretty much just any other B. Somewhat high end but nothing that really makes them different like Airstream trailers are different. At least as far as I can tell.
RE: airstream interstate
Harley Davidson and Beatrice Foods
Harley???
Wally's Airstream sold to Beatrice in about 1970 and Thor picked it up in about 1980.
But none of these owners changed the Airstream company or its products much. Like the Falcon to Interstate transition in B-Vans, most changes were 'market driven' and attempts to keep up with the competition.
I do think one should be careful to not draw conclusions from small samples. It is also a good idea to keep in mind that Airstream is a real RV and not an ideal one.
The company has its flaws and its products have defects and there are trade-offs made. That's real world.
RE: CA 299 to CA 89 to CA70 to US 395
For a more lonely experience, take 299 the other way, over to Cedarville, Then 447 to Gerlach and down to Fernley. Alt US 95 Then 208 and 308 to Smith and Sweetwater Summit (nice boondock area) to follow the East Walker to Bridgeport. Or you could bump over to US 95 to Hawthorne and then Anchorite pass 359/167 over to Mono Lake to avoid the grade at Conway Summit.
See Gerlach NV to Cedarville, CA and US 95 – Tohopah to McDermit for photo galleries and some other information.
RE: Battery Use Opinions.
Battery info on this forum is so biased it's funny
"biased" is being a bit polite, I think.
See Basic battery guidelines and compare and contrast.
Start to figure out why most diesel pickups have 2 12v parallel and so do most TT's that have dual batteries. Then figure out why motorhomes with battery banks with 8 or more often use 6v batteries. There are good reasons and understanding them will get you past a lot of the misinformation you find around.
As for AGM's like the Optima's, read the specifications carefully for charging voltages and how to obtain maximum life. They are nice batteries but a proper measure of what they offer is a bit different from what a lot of folks might try to make you believe.
A good example is the 'current' and capacity and amp hours and so forth. All lead acid batteries show the Peukert phenomena. That means the capacity is reduced when you use larger current draws. That is why any energy rating must also be matched with a power draw. For instance, the most common is the 20 hour rating which is about 60 watts for a typical 60 pound battery. Another common one is the 25 amp rate, usually expressed in minutes.
Also keep in mind that these batteries come with 3 factors traded against one another. These are cost, capacity, and longevity. Look at the line of batteries from a manufacturer and you can see they offer various models for different emphasis on these factors.
Also keep in mind that you can't measure battery capacity with much precision, Cycle to cycle variance, temperature, use profiles, and age can each have an influence on energy capacity on the order of 10% or more.
RE: Standard RV Furnace and Battery Power
As noted, a furnace draws about 5 to 10 amps or about 100 watts. A typical 60# battery like a group 27 has about 600 watt hours of available energy. That means about 10 hours of furnace run time on one battery. In cold weather with the furnace on a lot, that is one night. In cooler weather where the furnace doesn't have to work so much, it can last several days.
Then there's the other stuff. What really runs down the battery for a lot of folks is all the lights and watching a DVD movie.
RE: Can you rewire 24v solar panels to 12v at the actual panel?
What David 42 described is what smkettner suggested.
Modern solar systems with MPPT controllers that can handle higher input voltages will run at 24v or more in order to reduce loss between the panels and the charge controller.
The charge controller is the interface between your solar power side and your RV DC power side with your house batteries. You have to get one that works for your system.
You can also find DC-DC converters that will change 12v DC to 24v DC and vice-versa but those are most useful for running, for example, 12vDC appliances in an RV that has a 24vDC system. They are for changing voltage, not controlling solar power feeds to a DC system.
RE: Wire size?
The info I listed stands
touchy, touchy. I never said it didn't
What I did try to offer is a "why" to support your point and help promote understanding about what is going on.
The superflex example is an example of this idea. You can see the same situation in various degrees in any wire selection. Different insulation with differing temperature capabilities will result in different wire current ratings. An insulation that doesn't melt will be able to tolerate a higher level of heating (i.e. higher current) more safely than insulation that does melt.
The fact is that the two primary considerations in any wire selection are voltage drop and heating due to that drop and the power loss it represents. When you put a wire in conduit it can't dissipate heat as readily so its ratings are reduced, for example.
This is related to why you don't want your pedestal feed to the RV to be coiled up in a tight space in summer when running the Air Conditioner continuously, for instance.
The current capacity of a wire is not a hard fixed limit. Codes for the proper electrical wiring use certain guidelines for creating a measurable line between safe and not safe that is somewhat arbitrary but still useful. Anyone using wire needs to know that there is a code and the factors it considers and the assumptions used so they can fully appreciate the reasons for the concern and their applicability to various circumstances.
RE: Wire size?
First the wire size in "openair" can deliver far higher amps then in cord or conduit.
The limitation is based on how much current the wire can conduct without it self destructing due to heating.
To get an idea of the power loss in watts that goes into heating the wire, see Wire size considerations.
RE: Battery Minder Question
There is a need to be careful about what you are measuring and what you measure it with. And then you can get into variables such as temperature.
I don't think the BatteryMINDer is putting out pure DC (most good battery chargers and maintainers don't). That can lead to errors with many DC voltmeters.
RE: Wire size?
all the wire size is going to do is to change the time factor in charging.
Figure 3 wire gauge sizes will double the required time (if smaller wire) or reduce it by 2 (if larger wire) - with the assumption of a proper smart charger feeding the wire.
RE: Mechanical sway control no longer needed?
One of the oldest rules of thumb about sway is to apply the trailer brakes and keep up on the throttle until the trailer calmed down. Some brake controllers even had remote controls to make it easy to apply the trailer brakes when the trailer started to misbehave. I see no reason a modern tow vehicle with an integrated controller could not automate this process and do so in a much more effective manner than most drivers could.
I see in this thread a lack of distinction between catastrophic loss of control events and common trailer instabilities. Those are two entirely different phenomena. I think it does not help to think of them as the same kind of thing.
It should also be noted that sway control is often not needed, especially if the tow vehicle has a good hitch geometry, the proper tires, and a suspension that can properly handle hitch forces.
RE: grp 24s AH rating?
Plan on about 22 watt hours per pound of battery. That's about 2 amp hours at 12v. As many have noted, the group 24 is about 85 amp hours while a group 27 about 105 and a group 31 about 120.
Don't plan on any equalize sequence to do much good. The batteries in a bank should all be as similar as possible and if one is going bad it is usually better to replace the lot.
Forget the "deep cycle" skepticism and worrying - the differences are really not that significant for anything you will normally find in RV service.
a gaggle of smaller batteries can be quite a bit easier to manhandle that one big one (try to lift an 8d lately?). The key issue, though, is getting a fit between the space available and the batteries because it is the overall size (weight) of the batteries that has the most to do with the capacity available.
For running an inverter at fairly large loads, there are some advantages to having parallel batteries.
Les Schwab is a decent retailer and they stand behind their warranties and sell a lot of RV batteries. Those are good things to seek out when looking for batteries.
RE: Battery Minder
How long can the battery be connected like this......?
indefinitely and leaving it connected is usually good storage management.
The BatteryMINDer does the 2 things you need for a battery in storage. It keeps a top charge on the battery and it inhibits sulfation.
You do not want a lead acid battery to just sit. It will self discharge and grow lead sulfate crystals on the plates. A good battery maintainer that prevents these things from happening will help assure a healthy and longer living battery.
RE: Dual 12 Volt Battery Question
I think those with all of the expectations about the 6v myths (the true believers!) should really look at the data and be careful not to compare dissimilar circumstances.
Now, if you are one of those with an emotional fixation on the TDC6VGC myth, then read no further. It will only raise your ire. But if you are looking for a good and cost effective solution to your RV needs and have an open mind and can think rationally, ( ;-) ) ...
From Az Wind Sun FAQ there is no definitive life expectancy difference of any significance. You can also see this in battery warranties. Note that warranties are about the only solid indicator anyone can get because it is very difficult to find a spec sheet with this sort of data and that data is so conditioned as to make it difficult to interpret for an RV application. Look for yourself. I've done quite a bit of looking and am still looking so if you find something, please let me know.
Despite the assertions of some folks here, the people who deal with lots and lots of batteries in RV use just don't see it (although some say they do). That is why you don't often see RV battery banks with 6v batteries in OEM equipment unless you get into larger banks where it is just a logistical matter.
What I see happening most in these discussions is that someone has a single group 24 in their RV and it is nowhere near enough for their particular RV lifestyle. They upgrade to a pair of T105's or similar and, guess what?, they have enough battery and the batteries last longer!
The fact is that most battery failures in RV use are due to sulfation that occurs from poor storage maintenance or other abuse. That has little to do with the 6v myth.
From the spec sheets you will find that the all lead acid batteries suitable for RV use have a capacity of about 20 to 25 watt hours per pound. The trade-offs are cost, capacity, and ruggedness. Voltage isn't an issue as any differences in the 6v - 24v battery range are swamped by other considerations. (the number of cells can make a difference when talking about high voltage banks such as considered for some of the electric vehicles). Ruggedness isn't an issue in RV service, either, in this context (that involves use profiles and is a big topic in itself).
If you do find specs on discharge cycles, you'll find even SLI batteries are rated for a couple of hundred discharge cycles. Compare that to your usage over a 5 year expected battery life span.
I've had a pair T105's that didn't last the summer, Exide group 24's that served for more than 6 years before I replaced them just as a matter of PM, AGM's under the bed, 8d's that got abused, and just about everything in between. What I have learned is that it isn't the battery so much as how I treat it that counts. I have yet to find any solid reputable data to indicate any significant advantage of any one particular parameter that comes close to the impact of proper use and maintenance on batteries.
Now, I know how these ideas stimulate people. The flames get really hot and I've even had some get to the point of harassing telephone calls. That degree of emotion should, in itself, give pause. (although it does make a good case study about cognitive dissonance, logical fallacies, and other such stuff). I have learned a lot about physical chemistry, plate design, and other esoterica but the price paid has been rather high in forum damage and hurts.
Rather than flames and bald assertions, I'd like to see good data. For example, see Understanding batteries, start with these links - even some of these repeat the TDC6VGC myth but then contradict it in their discussion.
That's _good data_ I am looking for- what that means is data that accounts for both precision and accuracy, statistical fluctuations, pertinent parameters and conditions, backed by solid models and concepts, and can be repeated and substantiated and is appropriate and relevant to the RV lifestyle. Anecdotal is out, authoritative assertions are out, - good data and solid concept.
RE: Best way over Syskiyu Pass in Oregon?
Always carry chains that will fit your vehicle and know how to use them when travelling in the western mountains, especially in winter. Make sure your vehicle has other emergency preparedness gear as well. Do not underestimate the winter storms! Don't think you won't get caught, either. Surprises have happened to folks with tragic consequence.
You can try to bypass the problem by going over Willamette pass and down US 97 as a possibility. It is often a better route.
