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RE: Check Out US Battery's Compare of it's Batt to Trojan!
The article is long on performance and short on differences. They don't mention how long the charge time is, nor how much shorter it might be than the trojans.
this is probably because there isn't much difference.
lead acid battery design and manufacturing are both mature technologies. The differences tend to be within the range of variances in available energy capacity while in use due to such things as age, temperature, cycle to cycle variations, and use profile.
As for the infinite life Trojan's ... I wonder, if it were actually true that a Trojan brand battery lasted longer, why the warranty doesn't show it.
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bryanl
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05/12/12 09:19am |
Tech Issues
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RE: Can this be done? Charging battery question.
re: "The first obvious problem is that the truck batteries aren't deep cycle. You would certainly have a negative effect on the longevity of the batteries."
oh. no. not the deep cycle thing again ;-(
the term has no usable pertinent definition in the RV context, cycle life isn't an issue in typical RV use, ... what is at issue is that you just avoid any deep cycling of your batteries which is necessary in due consideration of an appropriate reserve as well as battery life.
I think Don is on the right track. It takes time to properly and fully charge a lead acid battery and such a charge is needed for best battery service satisfaction and life.
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bryanl
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05/04/12 10:07am |
General RVing Issues
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RE: Battery: Checking specific gravity
measuring specific gravity is hazmat territory and really not necessary for the typical RV usage with modern batteries. Besides the hazards, it also presents a problem for cross contamination.
Both specific gravity and voltage are direct measures of state of charge which is why there are so many tables around with both listed.
State of charge is useful to know when off grid so you can tell when to recharge the battery. State of health is of interest when figuring out whether the batteries need replacement and that is a different measure.
State of health usually needs some sort of load test although modern impedance type battery testers can make useful measures of this.
Again, hydrometry is hazmat territory and not really necessary in the typical RV situation. OSHA reports more than 3.000 US injuries a year due to batteries and the risk should not be minimized or set aside. Always use proper precautions and procedures when getting intimate with your batteries.
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bryanl
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05/02/12 12:43pm |
Tech Issues
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RE: Battery Life Expectancy ???
it is interesting how this topic riles folks ....
In re the variances in plate thickness for typical RV batteries: one suggestion I received was to actually look at them - I think that's a good idea (taking appropriate safety precautions). As far as the relative size of the variance, I consider using as a referent the one touted above for an industrial battery rather than the mean. (and do you really think 0.15 is thick?). You might also consider whether or not the differences in plate thickness have to do with its "deep cycleness" or with size or with some other factor.
As for 'true deep cycle' of any voltage - try to find a pertinent measure that can be used to segregate the 'true' ones from the 'not so true' and the 'not deep cycle at all' categories. If you can find some measure for this that is objective and useful for RV battery decisions, please let me know. I've been looking for one for years.
The 6v battery may be popular but it isn't the most cost effective in many cases. Last I looked at Costco, the price premium was almost 10%.
The issue is, as always, find me a measure, one that is objective and useful for my RV battery purchase decisions and one that someone will put their money behind.
BTW, battery reliability has a page on batteries that notes that capacity is mostly related to volume of electrolyte and current capability to plate surface area. Consider those in light of the reasons 'deep cycle, thick plates' has its fanatics. Interesting stuff and a good way to learn about batteries.
Find me the measure! (and please don't get silly).
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bryanl
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04/25/12 05:43pm |
Travel Trailers
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RE: New Baseline On Batteries
re: "I agree but a lot of people would rather just buy another battery than follow what they see as a complicated procedure."
I had a friend with this idea ... at least until he followed my recommendation to upgrade his converter to one that automated the complexity. Now he's changed his battery buying planning.
It takes very little effort and absolutely no need to get into complexities to follow Mex's advice - just the right equipment used properly.
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bryanl
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04/20/12 12:31pm |
Tech Issues
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RE: Battery monitor accuracy
Keep in mind that factors such as temperature, age, use profile, and cycle to cycle variance can each impact usable battery energy capacity by more than ten percent.
There is also the issue of battery charging efficiency.
A good integrating ammeter (battery monitor, electron counter), when programmed properly will accommodate many of these factors but they still limit its accuracy.
It is also a good idea to keep in mind that voltage is a primary and direct measure of state of charge. If you want to know the status of your battery's charge, the voltage, proper measured and interpreted, is all you need.
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bryanl
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04/20/12 12:28pm |
Tech Issues
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RE: Walmart "Deep Cycle" Batteries - Number of Cycles
What's not to agree with? Leaving the actual store aside, Windsun FAQ on batteries is one of the best, same as other their informational pages. It's interesting though, that mere existence of Deep Cycle batteries needs to be proven in so many pages on the forum (6 and counting)...
I agree, the NAWS FAQ is a good resource but you do need to read it carefully. For instance, it says that the batteries of the sort we commonly use in RV's have plates that are about a tenth of an inch thick, plus or minus half that. When talk is about much thicker plates, such as above, then the talk is outside of the context appropriate to these forums.
That is a key issue when reading about batteries. What is pertinent to my RV experience? Much of what is out there, and parroted in RV forums, is not pertinent to RV's.
As we've seen in this discussion, there is a lot of diversion and defensiveness and not much on what is useful to the audience here. There is not even any consideration I can see for an appropriate consideration of the nominal variations in battery measures.
The term 'deep cycle' as bandied about here is a case in point. Can you define the term in some empirical and objective manner? Can you make a case for why that measure is pertinent for a typical RVer? Can you show where cycle life is even an issue for the typical RV experience?
Does the discussion here support the idea of 'Walmart' batteries being different from others? Not that I can see. There is nothing here to indicate a proper measure of user satisfaction, manufacturing difference from the mainstream, or anything else.
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bryanl
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04/20/12 12:22pm |
Tech Issues
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RE: Battery or batteries I dont know?????
re: "I have not seen it mentioned, but one thing you might want to start saving your pennies for is a high quality converter."
very good advice. Find one that does multiple stage charging and has a maintenance mode that will keep a full charge without overcharging and implement a sulfation inhibiting technique. Examples are the Progressive Dynamics with ChargeWizard or Iota.
As for the "true deep cycle" and supposed 6v super batteries: despite personal experiences and anecdotes provided, the reality just doesn't bear it out. There is no objective empirical definition for 'deep cycle' much less 'true deep cycle'. Warranties, failure rates, and other such data does not support any longevity claims. Specification sheets belie any energy capacity claims. The NAWS FAQ is one of the few I've seen that discusses this.
Don't spend money that won't get you anything unless you really want to anyway. Bragging rights and brands do have a value but only if you can afford it. I do think it a good idea to know what you are buying, though.
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bryanl
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04/20/12 11:47am |
Beginning RVing
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RE: Battery Life Expectancy ???
re: "that and the solid lead plates as opposed to the porus ones that 12 volters usually have."
all lead acid batteries of the sort commonly used in RV's have what is known as Faure (sp?) plates. There is very little difference between auto and RV batteries and thickness is about a tenth of an inch plus or minus half that (re NAWS FAQ). Solid plates would be a terrible waste of resources .... This gets into why the term 'true deep cycle' is marketing hype and of little significance in RV battery considerations.
yes, pounds of battery. Since the energy density by weight for lead acid batteries fits into a rather small range, it provides a good way to get around all the BS that circulates in these forums and some of the errors in voltage based calculations. For instance, the 20 hour rate is at a draw of about 1 watt per pound, maximum charging rates run at about 4 watts per pound, solar systems need to provide at least one watt of panel per pound of battery,
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bryanl
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04/20/12 11:39am |
Travel Trailers
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RE: Airstream......??
re: "Maybe a lot of the reason the Airstream's "towed so well" was because the owners tend to invest in more premium hitches back in the day."
you should see the hitch my grandfather used to tow his 26' Airstream behind his Chrysler Imperial. It had no sway control and there was only 1 axle on the TT.
Used to be Airstream was at the top end. After watching the RV show on H&G TV, I see that now there are very many other rigs that cost quite a bit more, even TT's.
Getting a 20 to 50 year old Airstream as a cost effective RV for a family is no big deal. There are very few other brands in that class.
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bryanl
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04/20/12 11:30am |
Travel Trailers
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RE: New Baseline On Batteries
re: "A lot of this is complicated BUT... Although it might be over our heads" -- there are often ways of providing models of complicated things that people can use to help them understand what they need to know. This is where a good educator earns his wages.
A good solid charge to the point where acid in the cells bubble for twenty minutes is the best way to avoid stratification. I would do this every 2 weeks.
...
Certain premature death awaits flooded batteries that receive modest charges after sitting for months. Charge batteries well and truly full rather than let them hibernate at static charger float voltage month after month.
This advice is very hard for some to accept based on responses I have seen in some threads. It is especially pertinent to the RV solar boondocking crowd and the RV storage issues.
From what I have seen, though, following suggestions like this are extremely important when looking to maximize RV battery performance satisfaction.
Some of the issues here involve the classic equalization treatment that comes up now and then, desulfators (e.g. http://leadacidbatterydesulfation.yuku.com/ ), improvements in battery charge techniques and battery sensing, and battery monitoring devices. The specific gravity vs voltage debate and bank configuration issues are relevant as well.
A first step, from what I see, is to actually accept that a battery is not a simple electric energy storage device where you can measure net energy flow to determine how much energy you have left in the battery.
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bryanl
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04/17/12 01:38pm |
Tech Issues
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RE: Which Big Box Stores have Real Deep Cycle Batts?
re: "rated for CCA. Now it seems that the "tru deep cycle" batteries have the lowest ratings for CCA"
The thing is, CCA is not a "rating" but rather a specification. It can be measured for any battery and is a basic measure, along with such specifications as reserve minutes and 5 and 20 hour capacity values, that manufacturers use to position a battery in their line. These numbers are used to determine the Peukert coefficient which indicates the design battery impedance.
Notice the range cited for CCA. Without any consideration for battery type or size or focus, the extremes noted are still in the 30% or so range. Compare that to the effects of temperature, age, and other major factors.
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bryanl
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04/17/12 01:26pm |
Tech Issues
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RE: Walmart "Deep Cycle" Batteries - Number of Cycles
re: "WOW! They must have *really* improved batteries since I designed ... used to average ELEVEN 100% DOD cycles* before the 20 amp hour rate slumped 50%.
Optimum 20% DOD cycles yielded 500+ cycles, while 50% DOD yielded an average of 200 to 240 cycles before 50% A/H was broached.
Must be dilithium crystals added to the paste. Maybe they now green raw batteries in 200% humidity.
Perhaps trying to find understanding rather than using denial might be a better approach?
What is being said here, as I understand it, is that a person who claims to be a lead acid battery design engineer asserts that the typical experience of the automobile battery that gets run flat a number of times due to lights left on or whatever can't be. And that experience is refuted in very strong terms it appears to me.
In trying to understand this, I note the 100% DoD reference. Most of the lab tests for cycle life I have seen use an 80% DoD reference and an 80% of original capacity as the reference points for testing. The SLI battery data I have seen using these criteria tend to have a cycle life of 100 to 300 cycles. This does fit with the "Optimum 20% DOD cycles yielded 500+ cycles" being that that cycle life was to 50% rather than 80% of original capacity.
When it comes to matters like this, I think education and explanation would be a much better approach than sarcasm and ridicule. There are many issues to explore. One is the detection of end of life in an RV application. Another is the variabilities in RV usage profile and its impact on battery life. Another is the typical necessary RV capacity reserves and its impact on cycle depth. Another is recharge rates and charge completeness. Another is actual cycle length and its implications on cycle life over a nominal battery calendar life expectation.
Battery Reliability ... is a start on some of this. It'd be nice if there was someone in the industry that was able to participate in helping to dispel some of the many myths on these forums and contribute towards understanding batteries as they currently exist and are used in RV's. Instead, snarc and putdowns and such things seem to be more common and that seems a severe disservice to everyone here.
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bryanl
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04/17/12 01:17pm |
Tech Issues
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RE: ROLLS & SURRETTE CAR JAR & GOLF CAR BATTERIES
The base line in all of this is the fact that batteries are commodity items based on mature technologies for design and manufacturing. The market is extremely large and issues such as failure rates and performance are such that the batteries serve the needs for which they are intended.
All this bragging about significant failure, ability to buy fail safe, or whatnot is not based on reality.
Yes, there are some differences. Look at the specs and warranties and you'll find that the differences really aren't significant compared to how people use and abuse batteries.
Much of what I see in this thread appears to me to be myth mongering and misleading and, hence, irresponsible. It reinforces the old mantra about how to weigh what you read on the I'net and that, to me, is really rather sad.
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bryanl
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04/17/12 12:55pm |
Tech Issues
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RE: Battery or batteries I dont know?????
re: "I know I need a deep cycle but what kind do you recommend, what size, how many etc?"
dismiss anything that uses terms like "deep cycle" that have no useful definition or that get into the 'true 6v deep cycle golf cart" myths and its relatives. Voltage, brand, and market focus are minor and insignificant factors compared to inherent variables in batteries and how they are used and maintained.
Find a retailer who sells a lot to folks who use batteries like you do and stands behind what he sells. Then go by specifications, warranty, and cost.
I see the 'cycles' thing in here, too. Nearly any lead acid battery you can get for your RV will have a sufficient cycle life expectancy in typical RV use to handle every weekend in a typical 5 year battery life so that isn't an issue, either.
What is the biggest issue people face is that you just can't store much energy in a lead acid battery. Being happy off grid means trimming your battery use to fit what you have.
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bryanl
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04/17/12 12:26pm |
Beginning RVing
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RE: Battery Life Expectancy ???
re: "Preferably golf cart 6 VDC deep cycles."
there is so much bad information on this ...
Usable battery capacity is about 12 watt hours per pound and the battery voltage (6 or 12) is irrelevant. Battery life is also not a matter of voltage.
If you use proper units for power (watts) and energy (watt hours), it is a lot easier to make sense of things.
Battery energy capacity is rated for draws of about 1 watt per pound. Higher draws mean less available energy. You should only use about half the rated energy (the battery gets down to 12,0 - 12.2 volts after at least a half hour of no significant charging or discharging) for best battery cost efficiency.
A roof vent fan is a good way to improve air circulation in the rig. A 12v table fan such as Fantastic Fan makes is very good for a cool breeze to sit in. These can run at up to 100 watts or so.
A fan from a defunct PC can often be used in the refrigerator vent to help the fridge keep its cool. These can run about 10 watts.
Keep in mind that battery life is degraded when its temperature gets above 90F.
An inverter usually has about a 10% efficiency loss. If you use one of these, it should be connected directly to the battery with proper wiring.
A typical power outlet, cigarette lighter type plug in an RV is usually rated for no more than 100 - 150 watts.
There just isn't that much energy storage in lead acid batteries to do much so keeping your expectations in line with reality can be a learning experience.
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bryanl
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04/17/12 12:15pm |
Travel Trailers
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RE: Oregon/Nevada Hwy 140???
It is an interesting route. The Dougherty Slide is an 8% grade down to the west for a couple of miles that is popular for paragliders. There are a number of other similar grades and a few winding canyons en route.
The photo gallery - Burns to Denio to Lakeview might provide a preview.
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bryanl
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04/07/12 10:52am |
Roads and Routes
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RE: Walmart "Deep Cycle" Batteries - Number of Cycles
re: "Not true. Deep cycle batteries do exist, are made with heavier plates, and are designed to withstand repeated long discharges."
bull.
I really don't know of any more polite way to respond to this myth.
The curve for cycle life vs depth of discharge as linked up thread is typical for all batteries. It just shifts slightly depending upon chemistry, type, and whatnot.
Modern battery design and manufacturing is mature and highly optimized. Batteries commonly available at retail for RV and automotive use are more alike than different. Differences are in the same range as variability in available energy capacity due to age, temperature, cycle to cycle variations, and use profile. Look at the specifications and warranties and costs!
See http://www.mpoweruk.com/reliability.htm and other pages on that website for some good information about batteries.
For RV use, you generally need sufficient battery for two or three days off grid and then a reserve to handle cool nights or other contingencies. All of these factors mean that RV cycle depth is usually at 25% DoD or less. That leads to the conclusion that cycle life is not an issue for RV use.
What is an issue is use and maintenance. Anyone talking about their RV battery life is telling you about how well they take care of their batteries and not about the battery itself.
For best battery service satisfaction, you need a converter that does multiple stage charging and has a storage mode that will maintain a full charge and apply a sulfation inhibiting technique. You should avoid extremely large currents, deep discharges, and heat, You should recharge promptly with appropriate vigor and allow for a full and complete battery charge at least once a week (this sort of charge can take 8-12 hours).
BTW, re myths: the link above has a page that notes that capacity is a matter of electrolyte and current capability a matter of plate surface area. Think about those ideas and the implications of the 'deep cycle thick plates' rationalizations. -- I do know that this 'deep cycle' thing is all over the place but popularity does not make it correct or applicable to this context. Use critical thinking based on empirical measures and you'll get a much more useful outcome, I think.
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bryanl
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04/07/12 10:38am |
Tech Issues
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RE: Legality of required towing accessories
fear for lawsuit? probably overblown as it'd be extremely difficult to prove that a crash was caused by not having trailer brakes.
speed limit analogy? I know of several (many) cases of folks towing trailers over 3000 GVWR and not using the trailer brakes. Having a regulation does not mean people follow it nor does it mean that following the regulation is the only path to safety,
Safety? as seen by the ambiguity in the 'rules of thumb' offered above, this is not clear cut or well defined. The biggest issue probably isn't stopping distance but rather control over track during a hard stop. TT braking can also help in control during cross winds and other phenomena.
The regulation does hit manufacturers so trailers over a few thousand GVWR will have trailer brakes. A controller and wiring in the tow vehicle doesn't cost much (and many new ones have them installed OEM) so using the capabilities you have seems to me to be a good idea.
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bryanl
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04/07/12 10:04am |
Towing
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RE: Tire Pressure-Sidewall number, or number on trailer?
re: "I've always understood the correct inflation for a tire requires weighing the axle and then looking up the correct inflation in the manufactures data." -- that's an inference based on the effect that weight has on the tire. Better than nothing, maybe, but there are better ways.
The weight on a tire makes it flex on the road which causes heat. Tire pressure stiffens it and reduces the heat buildup. As noted above, heat is one of the biggest enemies of tires.
re: "If the tires are under inflated or over inflated, you do not have 100% tread contact." -- the thing is, though, that the traction depends upon both the contact area and the weight on that area so worrying about contact area is not a matter of traction. It is a matter of wear but, for most RV purposes, tires are replace by age, not wear so a bit of extra wear in the center is no big deal.
The general recommendation I have seen every now and then from manufacturers is to run TT tires at max sidewall pressure. The downsides are usually minor and the upsides are reduced risk of tire failure.
It is a good idea, I think, to get an IR thermometer so you can do a go-around at breaks to check tire and hub temperatures. If your tires start getting hotter than 120F after a half hour or more on the road, they likely need more air. They shouldn't go over 140F even on desert afternoon driving. If they run at below 100F, you might be able to get away with less air. If you seen any differences more than 10F to 20F, you might want to see if you can figure out what is going on.
The 'speed rating' for TT tires is, essentially, a heat rating. One way to keep tires from overheating is to slow down (less flex). Some manufacturers have recommended that you should exceed max sidewall by 5 psi or so if running at freeway speeds all the time but I think a bit of restraint on the speed is a better idea.
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bryanl
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04/07/12 09:53am |
Towing
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