Zephyrs

One of the questions trailer owners ask is about what they need in a tow vehicle for their trailer. This has been a very subjective matter with a lot of sales hype and FUD mongering thrown in. The SAE has put together a committee to provide a standard against which towing issues can be compared. Automobile Magazine says

There are five engineering characteristics that strongly influence any tow vehicle’s performance:

* The engine’s power and torque characteristics.
* The powertrain’s cooling capacity.
* The durability of the powertrain and chassis.
* Handling characteristics during cornering and braking
* maneuvers. The structural characteristics of the vehicle’s hitch attachment area.

Standard J2807 spells out test procedures and performance requirements that must be meant for a manufacturer to assign a maximum tow rating to a particular vehicle.

Most of the issues, concerns, and questions that have come up over the years in the ‘what can I tow?’ question have been addressed in the standard. For instance, a tow vehicle must be able to go forward and backward 16 feet on a 12% grade five times in five minutes as well as meet acceleration times over a set of defined speed ranges commonly encountered in driving. The Davis Dam run on 68 and 163 in Arizona is used as a criterion where the rig has to keep up a minimum cruising speed when temperatures are over 100F and the AC is on full. Handling is also considered. Turns up to .3g or so must not exhibit oversteer and panic stops need to stay in lane and be accomplished in specified distances at various speeds.

These criteria will not only help choosing a tow vehicle but can also be used to understand what the ‘experts’ think is necessary for proper and safe towing. Starting with 2013 models, you may see the claim that the vehicle meets J2807 SAE standards and that will provide some assurance about the claims for what the vehicle will tow.

If you live on your phone, the unlimited cell phone minutes plan is something you might try to hold on to. They may not be available for long.

If you don’t need your telephone with you 24×7 and reducing costs is a consideration, WiseBread has some ideas in Kick that Cell Phone Contract: Save with a Prepaid Plan.

There are two basic cell phone networks. You may have seen the advertisements about who has the best coverage. One network uses CDMA and its major provider is Verizon. The other uses GSM and its major provider is AT&T. They are not compatible with each other and phones for one will not work on the other.

Some of the pre-paid cell phone providers contract with Verizon, AT&T, and other network providers. Tracfone, for instance, will sell you a GSM or a CDMA phone depending upon where you say you want to use it. If you are in Reno, Tracfone prefers a GSM phone. If in Gerlach or Doyle, the choices are CDMA phones. Verizon has better coverage in the less populated areas, it seems but AT&T better coverage in town.

Another factor to consider is that GSM phones use a SIM card and CDMA phones don’t. The SIM card is a little memory card that you plug into your phone that contains the service information from your cell phone provider. It is a lot easier to plug that into the phone for both you and the phone company than having to type in long strings of numbers on a CDMA phone to do the same thing. That is why the CDMA folks are looking at A RUIM card (also R-UIM) or Re-Usable Identification Module as a means to control service more easily.

Note that pre-paid cell phone service is often very basic. The phones are inexpensive and don’t have a lot of the bells and whistles the contract providers offer. You will usually have to look for other options for I’net access.

A pre-paid cell service can be a very inexpensive option as a part of a more complete plan. If you wait until you find a wifi hotspot, you can use Skype or MagicJack to the long calls and keep the pre-paid calls short.

The market is in a turmoil and things are changing quite rapidly. There are many different ways to do things. That provides opportunities for meeting your needs at low cost but it also means it is easy to miss something. Keep your options and your eyes open. It can be fun.

Controlling trailer sway is often a hot topic in discussions. It is often difficult to figure out what to do to make sure the trailer stays behind the tow vehicle or why trailer sway happens. The recent labeling of the Lexus GX as a ‘do not buy’ by Consumer Reports (CR) has related causes. Why the Lexus GX may be rollover-prone (and the 4Runner isn’t) covers a number of issues that will help those towing trailers understand what is involved in rig stability and what modern vehicles do about it.

The first item is about oversteer. Trailers tend to exaggerate this because they push the rear out in when turning. “Cornering oversteer is something automakers try to avoid, except on high-performance sports cars. On SUVs with a high center of gravity, this is an especially serious problem”. Coupled with oversteer is that of lifting the throttle that CR uses in its tests to aggravate problems. Lifting throttle and failing to compensate for oversteer are primary contributions to trailer sway problems.

Electronic Stability Control Systems (ESC) were first adopted in the late 1990′s to combat the problem. “ESC relies on signals such as steering angle, lateral and longitudinal acceleration, yaw rate (the rate of rotation around the vertical axis), brake and throttle position, among others.” These systems can make your RV experience safer and more pleasant but, as in the Lexus case, they may not be tuned quite right and that may create problems.

It would be easy to read this article and just write off the problem as a technical, even computer, issue. That would be to miss what is being said about SUV’s, typical vehicle stability factors, and the implications of CR’s tests that are intended to bring out typical vehicle behavior problems. There are some things to learn that you can use to enhance your RV driving experience and comfort and safety.

The march of progress often goes by with little notice. CB radio was the primary option for in-vehicle communications only forty years ago and cell phones didn’t become a real option until about ten years ago. Fuel injection for vehicles really only become common something like twenty years ago and now the automotive computers carefully control engine fuel use in harmony with transmission gearing and other factors. Suspensions have also improved.

The last stage in developing robot capabilities in the automobile is in driving. Personal Navigation Systems are one step in this. TGDaily describes research that allows the automobile to stay in its lane without human control.

Already in cars are automatic parallel parking features, braking assistance, collision alarms, and trailer sway control. Being able to stay in line means being able to determine if the current vehicle path is staying in lane. That ability could be used to wake up a drowsy driver who might be driving off the road or into oncoming traffic – which is a major cause of traffic crashes in Nevada.

Maybe, one of these days, the joke about the new moho driver who sets the cruise control and then heads back to the bathroom won’t be such an odd absurdity. Perhaps the joke will be the moho doing a panic stop while on autopilot and what that does to the driver back in the bathroom.

Just you wait. We live in interesting times and driving is not like what it was just a few years ago – and will likely change just as much a few years hence.

The I’net is creeping into the RV lifestyle. The access to the world wide network is becoming a necessary link for everything from paying bills to chatting with friends. The government thinks it is so important that they have allocated some of the old UHF TV channels to be used for I’net access and even allocated funding. The website Welcome to Broadband.gov
has been set up with explanations and speed tests as a part of this governmental effort.

It used to be that you’d have to use satellite for I’net access on the road. This was slow, especially for uploads, and there was a latency that made it impractical for voice communications. Nowadays, you’ll find wifi access points at many RV parks and at some rest areas as well as at libraries, fast food and coffee joints, and other places. Cell phones are also moving to I’net integration. You may have seen the adds where the two major cell phone networks are fighting about coverage maps. DataJack is a way to access a cell phone network on a monthly basis without any longer term commitment.

A network telephone, called voip or voice over ip, can be a convenient and inexpensive alternative to a cell phone. Examples include Ooma, available at Costco. It uses a standard network device to make the connection between standard telephone and I’net. Magicjack is available at Radio Shack and uses a dongle for your computer that has I’net access. Both provide complete telephony services that you can use anywhere you can get a decent I’net connection.

Speed measures can be a bit confusing. You will hear terms like bits and bytes and have no idea how to figure out what it means for what you want to do. There is a table of these numbers at Network Connection Speeds Reference  for a start. Cell phone I’net access provides from 2 to 7 times dialup speeds. Bluetooth, used most often for those wireless cell phone earplugs, runs at a bit more than 12 times dialup. Wifi can run from 200 to 1,000 times dialup speeds. Home networks usually run at about 1800 times dialup speed. DSL, the connection that uses telephone wires, runs about 18 times dialup and cable, using the TV coaxial network, can run up to 100 times dialup speeds.

What speed do you need? Voice calls over the I’net need only 2 times dialup data speeds so Cell and wifi access will do just fine. Satellite would also do OK but the second or two lag in the link can require some adjustment. The need for speed will likely only be evident if you want to watch video or look at a lot of pictures. The base for that pushes cell phone technologies. The only choice for a true video nut is going to be cable at this time.

To find your connection speeds, you can use the government site or dslreports.com which need a Java plugin. Other speed test sites include
audit my pc (good speed chart by connection type, too) and  CNET Bandwidth Meter.

All of this is fine as long as you are somewhat near civilization – major highways or cities and towns. That doesn’t include some of the best RV spots, especially west of the Rockies. You can still get away from it all if you want but beware, technology is creeping up on you.

Spring is coming and that means its time to get the rig out of storage mode. That often means finding out what didn’t make it through the winter. The cooler temperatures are usually a good thing for your batteries because they reduce the self discharge rate but the long periods of sitting are not so good for the batteries.

Venkat Srinivasan, who works with the Lawrence Berkely National Lab, started a blog about batteries and an entry described the problem with lead acid battery life.

For a lead-acid car battery, the failure mechanism is called sulfation, where the discharged material undergoes a phase transformation after which it can’t recharge.
…
But, keeping a lead acid completely charged also leads to other problems (like grid corrosion) which would be lessened if you let the voltage decrease a bit. Moreover sulfation takes a few days. So one could do something complicated like let the battery charge, and then let it discharge a bit, but come back the next day and charge it back up before sulfation kicks in.

These two competing phenomena, sulfation and grid corrosion, may explain why keeping a float or trickle charge on the battery is not optimum. Float charging keeps a top charge to prevent sulfation but promotes grid corrosion. Solar charging systems may also tend this way as they spend perhaps a quarter of the time keeping a top charge. This may be why RV converters like the Progressive Dynamics with Charge Wizard do so well. Those maintain a reduced float level which keeps gassing and grid corrosion down. Every day or so, they bump the charge up for just a few minutes to inhibit sulfation.

There is a progression here. Float keeps the batteries always at top charge. Solar provides a top charge for maybe a quarter of the time. A good battery maintainer prevents discharge but puts a top charge on the battery only about 1% of the time.

For your spring time battery checks, make sure to your battery water levels of OK (unless you have sealed batteries), Disconnect the charger and maintainer (unplug the rig), turn on a load like a few incandescent lights (5 or 10 amps or about 100 watts) for an hour or two, then let the batteries rest with no load or charging for an hour or so. Check the battery voltage. If the batteries are good, they should show about 12.6v to 12.8v. If in doubt, consider replacement. Batteries often cost less than a tank of fuel for the RV and that cost may be good insurance against a dead battery on a cool spring morning.

Whenever someone thinks they know more than the manufacturer of a device or about the codes involved, you need to be very careful that you really know what is going on before doing anything. Howard falls into this trap in the February Blue Beret when he suggests modifying Honda gensets to implement neutral to ground bonding when the small Honda 120v gensets do not have a neutral to start with.

The lesson is that you need to be very careful in listening to recommendations from ‘experts’ and make sure you really understand what is going on. Be especially careful when the experts starting tossing around ‘safety’ as the primary reason for their recommendations.

There is no need or reason for an earth ground with a portable genset. The chassis grounds of the genset and the RV are connected together by the cord and plug ground wires and that is sufficient to provide a proper frame of reference for the fault detection circuits required in modern equipment. The reason for earth grounding is with grid attached power where the earth ground, chassis ground, and neutral are connected together only at the service entrance. This is why your RV circuit box does not connect these together as it is a sub panel and not a service entrance. The grid has long transmission lines that couple it to the earth which is why it needs careful earth ground considerations. Your RV on its own, off-grid and local, power systems does not have that problem and, hence does not need earth grounding for power safety.

You do not have a safety hazard as long as the power circuit is isolated from your RV frame and the earth ground, despite what Howard says. This is why the code is as it is for small gensets or other power supply devices (like battery powered inverters).

Your 3 light circuit indicator is designed for grid power. When using small gensets with plugs, it is entirely proper for it to not show a light for hot to ground voltage as the hot and neutral sides of the power may be isolated from everything else. Like with the voltmeter, you need to use the proper test equipment and properly interpret their readings in the context of what you are doing.

The column also gets into the problem of a genset not being able to power things such as air conditioners and microwave ovens. The lesson here is to watch out for oversimplification. The reasons why a 3kW genset might not power a 1.5 kw microwave include many factors. Altitude effects on genset performance is one. The appliance power factor is another. Power startup surge might be another. Hidden loads (the fridge going to electric is a common one) can be a source of failure. Even the type and length of extension cord you use between the genset and the RV can be a factor.

When you have larger gensets or wired in gensets, then you should have a transfer switch that will automatically make the proper connections.

Note that circumstances determine how things are done. Single phase small 120v portable gensets that use plugs are not the same as house backup systems or contractor power. Sometimes you know the generator is completely independent of any other power source or not. Sometimes, especially with portable equipment, you do not know for sure it is really a ‘separately derived system.’

A 2-wire 120 volt system has no neutral and therefore bonding is optional. Recall that neither side of a 2-wire derived system is a neutral and when one grounds either side, it becomes a grounded terminal or conductor, but it is not a neutral. (OSHA 1993 clarifying letter)

Definitions of terms such as neutral and ground confuse people, too. A neutral is halfway between the two sides of a split phase 240v system, not an arbitrarily selected side of a 120v system. Chassis grounds and earth grounds are two separate things. Unless you and the expert are very careful with terms, confusion can result.

There is a lot of bad advice out there. Forums and discussion boards are particularly poor sources as they don’t do any filtering. Magazine columnists can also go astray. It is up to you to properly qualify what you find by using sound logic, gaining a proper understanding, and using multiple sources of information.

See Also

see OSHA Grounding Requirements for Portable Generators and Using Portable Generators Safely

PORTABLE GENERATORS AND OSHA CONSTRUCTION REGULATIONS is by “Grizzy” Grzywacs at the OSHA National Training Institute. He had a ‘discussion’ on RV.NET where he very patiently went over the genset grounding issues with some recalcitrant objectors and that provided a good tutorial that is summarized in the paper linked here. (the RV,NET blog has the same bad advice as the Blue Beret, though)

Solid Grounding For Your Generator thinks through some of the issues. Another EC&M column on this is about how you should treat the neutral conductor. Mike Holt also talks about the National Electric Code on Neutral to Ground connections to describe what the code says.

The IMSA describes Generator Grounding and when ground rods are required at portable generators. The article carefully describes what a “separately derived system” is with illustrations. Also note

“Portable generators are covered in Section 250.34 Portable and Vehicle-Mounted Generators. This section allows the generator or vehicle frame to serve as the grounding electrode when:
(1) The generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
(2) The non–current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame.
…
If the generator neutral is grounded then the generator can only be used with a transfer switch that transfers the neutral, or as a stand alone generator for a carnival or special even, and then ground rods are required.”

Generator Joe also has some good ideas for the proper operation of your portable generator.

With I’net searching, it is easy to find good resources to use to understand technical issues. Don’t get caught by bad advice, even if it does have the imprimateur of print in a journal or magazine. Electrical power is nothing to mess with so don’t think you know more than the NEC, OSHA, and the OEM unless you have the background and the resources to outweigh those authorities.

Marks RV has an interesting page about the properties of LP gases including both propane and butane. Near the bottom of the page is a table that provides information about the BTU per hour as a function of temperature and tank type. It tells the story of why keeping warm in cold weather gets difficult from many directions.

For the typical RV with 30# propane bottles and a 30 kBTU/hr furnace, the furnace is going to be fuel starved when temperatures get below 10F or your tank gets below 20% full. The factors behind this include the surface area of the liquid in the tank and the fact that it is tougher to get from liquid to vapor when the temperature decreases. A chart on the page puts propane vapor pressure at 0F at only a quarter of its value at 70F. If you have a lot of Butane in the mix, which might happen if the tanks were filled in warm climes, then getting vapor will be even more difficult as butane has to get to 100F to have the same vapor pressure propane has at 0F.

The bottle size is one reason for getting a large, rented, bottle when parked for the winter. From the tables, a 20# tank nearly full could just barely fuel the furnace at 20F and a 65# under mounted tank could be 30% full and keep the furnace going down to 0F.

The website also has a good rundown on troubleshooting your RV furnace that will help you learn how it works.

Coyote Blog has Total Frustration With Arizona Parks. He runs a business of privatizing public recreation and knows how to keep state parks and similar recreation areas financially viable yet cannot convince the authorities to act on his knowledge.

Of course, I am not completely naive. I know there is a tried and true kabuki dance here where parks departments threaten to close down the Washington Monument in a bid for public sympathy that will either deflect budget cuts or spur new taxes. I also know that state parks directors have sworn a blood oath together never to let private concessionaires run whole parks, even if the parks have to be shut down

The places we like to visit in our RV’s make for good symbols because they are ‘recreational’ and, hence, luxuries that are not critical to the state and they are visible. When times are good, that is why they get a lot of extras and fancy geegaws and RV spaces with utilities and fancy trails and facilities. When times are not so good, …

The observations in the commentary are worth considering. They touch on how government and social ideology influence our access to outdoor opportunities with our RV’s.

When you try to find out how an RV refrigerator works, it can get you to wondering how on earth somebody could invent it. RV Mobile has a good rundown on the process using ammonia, also known as refrigerant 717.

The process occurs in a sealed pressurized set of tubes that has enough pressure in it to liquify ammonia at room temperatures. It has a hot side where ammonia is separated from water and a cool side where the ammonia gas is mixed with hydrogen to change its partial pressure and allow it to evaporate and provide cooling The hot and cold sides are separated by liquids with liquid ammonia in the condenser at the top and a water and ammonia solution in an absorber at the bottom.

Three chemicals are needed for the refrigerator: ammonia, chosen because of the amount of heat it can carry and its boiling temperature; water, chosen because it will dissolve a lot of ammonia and be a liquid when ammonia is a gas; and hydrogen because it can take up space in a gas providing a partial pressure and won’t dissolve in either liquid ammonia or water.

A key to how it works is Solubility of Ammonia – NH3 – in Water. Ammonia gas is readily dissolvable in water but how much is temperature dependent. Going from room temperature to body temperature water, the amount of ammonia that can be dissolved decreases by nearly half. That’s a range from about a pound to a half pound of ammonia in a quart so adding a bit of heat can release a good amount of ammonia.

When heat is applied to an ammonia solution in the percolation (perc) tube, three things are happening at once. One is that ammonia gas is released as the solution with water heats up. A second is that water is separated out of the ammonia vapor. A third is a concentration of the ammonia in solution going up the tube. Ammonia gas comes out the top and any water that tries to escape with it is shaken out and sent back to the absorber tank. The heating that pushes gas out the top of the perc tube is also what drives the cycle.

The condenser cools the ammonia gas which allows it to liquify. This is where the heat is removed from the refrigerator. Ammonia drips out of the condenser into the evaporator which has hydrogen trapped between the water below and the ammonia above. That gives the ammonia room to evaporate to share space with the hydrogen. This evaporation is what provides the cooling. As the ammonia drips on down the evaporator, more and more of it evaporates and that means its portion of the space shared with hydrogen increases. That means that the boiling point increases. So the higher part of the evaporator is used to cool the freezer compartment and the lower part is for the refrigerator. As the ammonia gas mixes with the hydrogen gas, it makes for a heavier mixed gas that settles down towards the absorber tank. That exposes it to water which dissolves the ammonia and leaves the hydrogen, which, being a light gas, rises back up to the evaporator.

The whole thing depends upon heat rising and stuff sliding down tubes of various sizes to control the flow of the chemicals in a way to provide cooling. That is why the refrigerator in your RV needs to be fairly level to function efficiently.

Several discussions have come up on the forums about safety and risk. There are those who are very worried about hitch rigging or travel weight and other things being unsafe. The Nevada Crash report for 2006 (big PDF) indicates that worries are misplaced.

In the table about types of vehicles involved in all property damage, injury, and fatal collisions, 162 “motorized homes’ crashes included only 3 fatalities. Golf carts were in 3 crashes and tent trailers and travel trailers in 2 each with no fatalities in any of these. This is out of 114,632 crashes reported. That puts travel trailers at one percent of RV crashes in Nevada in 2006 or at a rate of about 17 per million of all vehicle crashes.

There are reasons for this that include driver maturity and a tendency to avoid traffic congestion. At just single digit events in a year it would be very difficult to accumulate meaningful numbers about causes and risks.

The bottom line is that the risk is very very small for the RV community. When you see someone on the forums spouting off about how some hitch is a safety hazard or expressing a desire to leave the state if someone dares to get on the road with some rig that isn’t on their approval list, write them off as a blowhard who has lost touch with reality.

Continue to take care of your rig and pay attention when driving. Enjoy the Sierra Nevada and Great Basin RV experience.

6 Obnoxious Old People Habits (Explained by Science) by Ian Fortey at Cracked.com is a bit crude but provides some things to think about. You may remember your grandparents – hopefully while they were still of an age to be enjoying the RV lifestyle and, perhaps, visiting your house. If so, these Old People Habits (OPH) might not have been truly obnoxious, at least not quite then.

So when you’re late for work and get stuck behind one of these guys, and swear out loud that you’ll never be a slow driving, high pants-wearing, hard candy-sucking Yoda, just remember: at your age, that’s what they said, too.

Keep in mind that you, too, might be a grandparent visiting your grandchildren. Enjoy it while you can and try not to let the wear and tear on your systems become obnoxious habits that overcome what you can offer to your family. A bit of knowledge might allow you to compensate. Maybe Fortey can help you look in the mirror and see what is really there.

Jim has a good rundown of things you need to know about credit and debit cards. These are a convenient and safe way to pay expenses, especially while on the road. Here are the topics he covers:

• Different Types of Cards
• Anatomy of a Credit Card
• Paying Back & Grace Periods
• Fees
• Reward Programs
• Lost or Stolen Cards

Don’t forget to check out some of the links, too. That is what the web is all about – following the trail to fill in the gaps of your knowledge. These cards are tools and, like any tool, keeping them in good condition and using them properly can make getting the job done right a lot less hassle.

Maintaining a comfortable temperature inside an RV is a significant energy problem. The RV is often exposed to the elements and cannot devote a lot of space to insulation or machinery.

The rule of thumb for furnaces is that an RV needs a furnace that will provide 1000 BTU per hour of heating for each foot of length. Air Conditioners provide about half that for cooling but then heating often needs to maintain 40 degrees of temperature difference (from 20F to 60F) while cooling just 20 (from 100F to 80F).

An average office building uses 92 kBTU/sq foot/ year (energy metrics). For an 8×30 foot space like an RV, that’d be 23,552 kBTU/year or 64.5/day or about 2.7 kBTU/hr.

These guidelines provide a range from a peak need of about 30k BTU BTU per hour to a bit less than 3 on average. The ORNL biomass conversion factors can provide an idea about what that means in terms of energy sources. (they also provide data to help you calculate the carbon footprint if you are into that)

See convert units for a very nice calculator for distances, units conversion, and other things.

For Energy: Wood has about 6400 BTU/lb, gasoline 115k BTU/gallon, propane 93k BTU/gallon, and a typical RV battery 3400 BTU (but only half usable). What this means is than an RV might use each day, on average, ten pounds of wood, a half gallon of gasoline or a bit more than that of propane, or twenty batteries worth of stored energy.

For Peak Power: The 30k BTU/hr peak power would mean a consumption of five pounds of wood per hour, a third of a gallon or propane or a bit less gasoline per hour, or ten batteries of energy each hour.

Solar is sometimes sold as an ultimate solution. Consider that the absolute maximum power from this source is 3k BTU per hour per square yard (SMPS). With a typical 10% panel efficiency this means about 350 BTU per hour from a standard RV type solar panel. That means nearly ten panels would be needed to supply peak power needs and that would only happen with optimal sunlight conditions on the panels.

Note that these calculations are very rough. An RV isn’t an office building and the peak needs don’t consider extreme circumstances or efficiency factors. See the ORNL page for some idea about how these can be considered. Check the arithmetic! The numbers seem reasonable but errors can happen and sometimes reasonable isn’t reality. Peruse the references, find other resources to compare, check the arithmetic and make other comparisons. You’ll gain an understanding about why things are done the way they are and be able to compare your needs to your options better.

Getting the right wire size is a matter of distance and current. There are two issues to consider. Voltage loss is important as most equipment is rated for best operation at a particular voltage. Power loss in the cable is important because it indicates a risk of overheating cable or connections.

The table shows common wire sizes and the resistance in ohms per thousand feet. The “line” column shows the resistance you’d have in a ten foot cable powering some device. This is for 20′ of line as you need to consider the round trip. Voltage loss and power loss are show for that 10′ cable for 5 amps, 10 amps, and 100 amps. The voltage loss is shown as a percent loss for a 12v circuit.

From Wikipedia on wire gauge: use the resistance table and calculate the voltage loss and power consumed by a ten foot run of wire at 5, 10, and 100 amps. Here’s the result.

The voltage loss area marked in red is where the drop is more than ten percent at 12v. Note that the power loss columns apply to any voltage.

A convenient fuel for the RV often sits in bottles standing at the tongue of a trailer or in a tank alongside the frame underneath a motor home. Propane in the tank is under pressure (up to about 250 psi) to keep it a liquid. These tanks contain about 430,270 (20#) to 860,542 (40#) BTU’s of energy. That won’t last long if using propane to heat the RV in winter but does quite well for water heating, cooking, and refrigeration most of the time.

Propane 101 promotes propane safety through better understanding. Consumer propane cylinders describes the common bottles you’d see on the tongue of a trailer. Understanding Your Propane Tank and Propane Cylinders provide a good description of the parts and pieces involved in propane storage. Check out the index for other pages with good information.

The GasCo glossary of terms is oriented towards residential use but still provides a good start on terms you need to know about propane and its use.

Some other propane safety articles to peruse include Camping World’s Play it safe with propane with good note about alarms, New Car Buying guide Propane safety for RV Owners with a checklist, Funroads with when full is too full, Propane safety dot com to get technical, or Dave and Helen’s on propane tank valves and re-certification.

Raso enterprises provides some interesting pictures and discussion about proper propane tanks as vehicle fuel sources. It provides some insight into the differences between the motorhome and trailer propane tanks.

The need was for an oxygen concentrator prescription after heart surgery. The solution was a genset in the back of the tow truck. The problem was CO getting into the RV when the wind went the wrong direction.

You must have functioning detectors and alarms in your RV anytime you are anywhere near anything combusting including gensets, furnaces, RV refrigerators, or catalytic or similar space heaters. You should also have combustible gas detectors in case of leaks. (See the Safe Home Products Page for definitions)

RV ratings for alarms and detectors account for the confined space in an RV and the broader range of expected temperature and other conditions, among other things. Make sure any alarms and detectors in your RV have a proper UL listing for RV use.

Detectors age and may need replacement every few years or so. Read the owner’s manual for guidance on this.

Where detectors are installed depends upon what it is trying to detect. Smoke and CO detectors are usually placed high on the wall and combustable gas detectors low.

Check the UL page on CO Product Safety Tips or PDF

The Safe T Alert is a common detector for RV’s. It runs on 8-16v with a 60mA current draw and an operational temperature range of -40F to +140F – this provides a contrast to the usual 110v +40F to +100F specifications for a typical household detector. (Camping World has these for a bit under $60 – Safe-T-Alert Carbon Monoxide Detector with FREE Smoke Alarm and Safe-T-Alert Detectors)

Here’s an Atwood RV alarm at PPL with a digital display that also runs a bit under $60. With a display, you can see how much the stove and oven add to rig CO content. See the battery powered CO Detector at Atwood. Be careful not to use micro measuring to feed paranoic tendencies!

Here’s the Atwood for about $50 at Mac the Fire Guy along with some other fire safety stuff.

The Army has Guidance on the Use of Heaters Inside Tents and Other Enclosed Shelters.

RV Safety Systems has Safety Related Alarm Systems for Buses/Motorhomes that provides some good data as well as descriptions of other alarms you might consider.

The Wisonsin Department of Health Services has a good summary of Portable Generator Hazards that includes CO as well as electrical hazards.

Make sure you have the detectors you need and that they are working properly when you use your RV. It is much better to be awakened in the night by an obnoxious alarm than to suffer fire or other disaster.

Most of us just fire up the genset and plug in. Every now and then someone wonders about whether it would be a good idea to provide an earth ground or whether the wiring is the way it should be. John Grzywacz runs through the wiring codes and their rationales in his paper Portable Generators and OSHA Construction Regulations (PDF).

The recommendation is against earth grounding as that just provides another electrocution hazard with a portable genset.

Ground fault interrupters used to not be required but that exemption seems to have been dropped in the NEC. Three factors are considered by OSHA. These are 5kW or less, 2 wire single phase, and no connection between the frame and the circuit wires. Because OSHA and NEC have different ideas, there may be some confusion. It is likely that the trend is towards GFI in all cases.

The third issue is the neutral and frame ground bonding. It appears that the NEC requires the connection for any genset, like an RV genset, that is not otherwise connected to any power system. This issue seems to have caused some differences in how the popular Honda 2000i is wired between Canada and the U.S. Note also that bonding the neutral and frame ground would eliminate one the three conditions necessary for the GFI exemption.

Grzywacz explains the why of these issues and that can help you understand what is going on with your genset.

Warren Meyer, a small business owner in Phoenix, Arizona took a look at the Economic Impact of Gas Prices. There has been much discussion about the recent bump in the cost of energy, especially for the fuel we put in our RV’s. Some are limiting their excursions to avoid the pain at the pump. The Coyote Blog post took a time out to consider the big picture. How has the fuel cost changed over time as a part of our per-capita disposable income?

What prompted the Coyote Blog post was Economist Mark Perry, at his blog Carpe Diem.

For gas to reach a record high as a percent of per-capita disposable income, it would have to sell today for about $5.50 per gallon to reach 14.90% of per-capita disposable income, like it did in March of 1981, when gas sold for $1.42 per gallon, and per-capita disposable income was only $9,500.

It looks like the cost of gas ran about 6% of disposable income from 1985 until recently. Starting about 2003 it has increased from there to near 10%.

Meyer realized that the price of fuel was only a part of the picture. He factored in the average MPG rating for passenger vehicles to determine the fuel cost for a typical 15,000 miles per year. That graph accounts for the improvements in efficiency and starts its rise from about 3% in 1998 to a current 7%.

You might think that RV fuel efficiency hasn’t changed as much as it has for passenger cars but consider: A typical Suburban tow vehicle used in the late 70′s through the 80′s got about 8 miles per gallon. A modern diesel with the same trailer can get up to 14 and the big block gasoline tow vehicles will get 10 to 12 mpg. That’s an efficiency improvement of 20% or more in fuel efficiency. So Meyer’s adjustment makes sense for RV’s, too.

The pain at the pump has put some people in a panic. There is talk of re-doing the seventies with price controls and the double nickel speed limit. They didn’t work then and took a long time to get settled. It may be why there is a sharp drop to a fairly steady level starting about 1985 in the graphs. A proper perspective and learning from what has been done before will help to avoid repeating the same mistakes.

So, while I too think paying $4 for gas is not my favorite way to dispose of my income, in terms of average household pain created, gas prices are quite far from their historic highs.

It will take some time to settle things out. There are many experts trying to figure out why dropping demand has not had an impact on prices. There is also some wondering about why the pipeline isn’t getting clogged as supply keeps up and demand drops. There is also quite a bit of ‘blame game’ going on looking for scapegoats and conspiracies.

The increased pain at the pump has dampened demand. It is also stimulated a re-examination of ideas about energy and where we get it and how we manage it. That should lead to good things.

But, for now, perhaps the best bet is to put more emphasis on enjoying the places you visit rather than the journey and travel for its own sake. If history is any guide, this will work itself in due course. All you have to do is to be patient and avoid succumbing to the fear mongering that is being peddled in the news.

There is a lot of information out there about lead acid batteries. Here are a few websites that you can use to learn about this well established technology, how it works, and where it is going. As always, exercise critical reading and thinking skills. Some of these pages have errors, some have assumptions that may not work well with your interests, some simplify things in ways that may mislead – that is why you need to be careful about what you get from your research.

Theory

operation and construction – Nuclear Power Fundamentals? but really, a good rundown on the chemistry with diagrams showing plate construction.

Battery Basics A good rundown on the basics that isn’t too technical from the maker of one of the better RV converters.

The Basic Chemistry of Gas Recombination in Lead-Acid Batteries – this is about the sealed batteries that first appeared in the 1970′s and how they work.

Battery Basics – fireflyenergy.com – You might have to dig a bit here as this website for a new battery technology project is quite active. The focus is on explaining the current technology as a reference for their new one.

lead acid batteries, battery history types and development – solar navigator world electric navigation challenge, nelson kruschandl, bluebird electric land speed record cars – the focus here is on solar systems so be careful about context as the range they discuss is much broader than that normally found in the RV community.

Part One – Basics every battery user should know – a gateway to a number of articles about battery at the Battery University

Battery Modeling for HEV Simulation by ThermoAnalytics Inc – if you want to make a mathematical model of your battery, this is one place to start.

The ABCs of AGMs. (PDF) – some nice pictures and a lot of good advice about this battery technology and how to get the most out of it.

Batteries – University of Hawaii amateur radio enthusiasts explain how batteries work.

Batteries – fundamental theory and concepts.

How Lead Acid Batteries Work – and some nice diagrams for wiring battery banks

Frequently Asked Questions

Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and – the BatteryFAQ.org entry page with links to several documents.

Az Wind Sun Battery FAQ They call it the “The Ultimate Deep Cycle Battery FAQ” and it isn’t bad … but, again, be careful of the broader scope of the solar alternative energy bias.

Car and Deep Cycle Battery FAQ – check the battery life expectancy map from Interstate. This is another solar and alternative power site. The same FAQ is also at BatteryFAQ.org as part 7

Pacific Power Batteries – About Automotive Batteries – this one has some good stuff to look for if buying a battery.

deep cycle battery frequently asked questions – this one is a bit more technical and has some good diagrams of construction and charts for temperature effects and other phenomena.

Car and Deep Cycle Battery FAQ – part 16 of the BatteryFAQ.org documents about how to revive a sulfated battery at RPC.

Exide Technologies FAQs – Marine & RV Batteries – takes some liberties to simplify things but covers some good topics.

Battery Tutorial | Batterystuff.com – some good information about why batteries fail and a nice chart of specific gravity and voltage as a function of state of charge.

Buying guides

DIFFLOCK.com – Battery Guide – This is another page found copied in several places. Do check the section on how to determine the date of manufacture for batteries.

what do i look for in buying a new battery? A part 7 FAQ copy.

what do i look for in buying a new battery? – Bill Darden’s part 7 at the Optima Battery website

battery criteria performance ranking chart (PDF) – Flodded, AGM, or Gel, which is best? As with any rating, the key is to figure out what is actually being evaluated. This PDF has a nice rating chart and a page defining the criteria that may give you an idea about what to think about when buying your own batteries.

Download specs for Exide batteries (PDF)

Use and maintenance

Batteries — and Other Electric Stuff by phred – some good tips for your RV battery use and maintenance.

Battery Desulfation – Projects – build your own! Learn about what it is and what you can do about it.

Aviation Battery Plate Sulfation and Resultant Degradation Explained – “Battery Plate Sulfation For Us Dummies” some good stuff on charging and maintenance, too.

Battery Maintenance InformationHow to keep your golf cart batteries from going dead over winter – some lessons for the RV, too.

Exide :. battery servicing tips – page load error? you try it, maybe they have it fixed again.

Preventive Maintenance, Charging and Equalization info – if you are really into the hazardous realm, here is the manual for the hydrometry enthusiasts and bona fide equalizing community. Again, solar and alternative power oriented and not so much for the Rver except as a reference.

The care and feeding of solar batteries by Jeffrey Yago, P.E., CEM Issue #95 – the top half is ‘why’ and the bottom half is “how” to maintain your batteries properly – again, an alternative/solar bias.

Lead-Acid Battery Info – “LeadAcidBatteryInfo.org is your resource for information on the use and recycling of lead-acid batteries. Look to us for information and the latest news on how lead-acid batteries are being used in environmentally friendly practices such as recycling and hybrid car production, as well as in workhorse and mission-critical situations that require a truly dependable power source, such as the backup generating system at your local hospital.”

Good Sam RV Emergency Road Service – Battery Basics – how to keep the going and going …

Notes on Batteries – a Peukert calculator and how to figure batteries in serial or parallel.

RV Camping with Solar Power – this is a ‘HowTo” for those thinking about engineering a solar system for their rig. His use profiles include amateur radio field days and star parties.

Testing

Battery charger and battery analyzer experts – Cadex Electronics Inc. – describes the kinds of battery tests that can be done.

Battery-Web.com – Battery Tester FAQ – they are selling their gadget and present an interesting viewpoint of battery technology in the process.

Conductance Questions and Answers (PDF) – Midtronics has this effort to help you understand how these battery testers work.

Using conductance technology to ensure battery system reliability (PDF) – this is an industry white paper.

Battery Testing Using Conductance Technology for NSB Series Valve …(PDF) – Northstar Batteries starts with a simple circuit model to describe how conductance testing works and some nice graphs about what happens when using conductance testing properly.

Battery Testing Using Conductance Technology (PPT) as an aid to determining replacement strategy. The slides in this presentation have some good meat and reference a lot of other material on the topic.

Advanced battery analyzers starts with “What is the difference between CCA and RC?” and helps you understand how that question is a key to learning about battery health.

conductance testing questions and answers – more questions answered based on the Midtronics sales effort.

Bogart Engineering: manufacturer of the PentaMetric battery monitor which measures volts, amps and amp-hours for battery systems used in homes, RV's and boats.

Xantrex Technology Inc. – Boats – Link 2000 & 2000R – Product Information – a popular net energy meter for use with their inverters.

Xantrex Technology Inc. – Link 10 – Product Information – a popular battery monitor.

Digital DC Ammeter, Amp, Watt Hour, Battery Fuel Gauges & Meters – more ways to measure your battery parameters.

Watts, RC Watt Meter, Power Analyzer WU100 Version 2 – WU100 – an interesting DC power meter

Applications

Electric Vehicle Battery Information – like he says “Get the Coffee! It’s an all-nighter.” – the page is a gateway to a lot of battery information. This is a good resource if you want to see what else there is besides the lead acid battery.

Power Technology, Inc., PWTC, New Battery Technology – this and the Firefly project look to be two significant advancements in storage batteries that might be applicable to RV’s. You’ll need to browse the site to find things, though. Look for the ‘technology’ link in the menu.

www.happy-wanderers.com – a 6v series vs 12v parallel treatise that promulgates a few myths. See if you can find them.

AGM Toch Battery Power for Solar and Wind Power Systems – pros and cons from an AGM manufacturer.

Remy Battery(PDF) – these guys had a good PDF on sla and gellcell maintenance but it appears it moved. Check the site and you might find some other interesting educational nuggets.

Batterytender.com – Home of All Your Charging Needs – Their Introduction to Lead Acid Batteries is a good rundown on the basics. They sell a battery maintainer and desulfator that has a good reputation.

Car Battery and Deep Cycle Battery References & Information Links – Bill Darden provides links to a lot of manufacturers for various things battery.

lead acid battery charging – explains charging stages and voltages.

Tech Talk: Battery Maintenance – another moving link at Interstate Batteries. Hopefully you’ll find a page with links to good stuff.

USMC lead acid battery training (PPT) – for some reason this one causes Open Office Presentation to abort. It was a good training presentation when last viewed.

Carbon foam liberates lead-acid batteries for emerging military missions – the Firefly project

Firefly revamps the lead acid battery | Tech news blog – CNET News.com

Also check the Understanding section of the Owner’s Guide for pages on batteries, configuration, energy, and power. One of the more contentious, yet important, laws about the behavior of batteries is explained in the page Understanding the Peukert Effect.

Again, read carefully and don’t just take what you find ‘as is’ – learn about what is behind the conclusions and what peculiarities of measurement are behind the assertions. Boil it down to something that makes sense and can be useful.