Archives for January 2010

Jan 20 2010

Sunny rainy days

Ironically, as I sit down to write up this blog which is eventually going to discuss solar energy, the weather here in Tucson is astonishingly wintry. Three Pacific storms are blowing by this week, each one bringing more rain and wind than the previous one. Last night we heard the unfamiliar sound of heavy rain pounding our flat house roof in the desert, and this morning we woke to crystal clear air, sidewalks and driveways scrubbed clean of dust, a few downed palm fronds, and beautiful views of snow in the Catalinas above 6,000 feet.

Webcam image courtesy of UA Computer Science Dept.

Even when our forecast looks like this, it’s usually sunny most of the day in Tucson. They get excited about rain here, for obvious reasons, and a “winter storm” has an entirely different meaning than it does in the rest of the country. Here, it means wind, a little rain, and maybe a thunderstorm. “100% chance of showers” doesn’t mean rain all day; it means definite rain at some point in the day. Freezes are rare except in the mountains.

Normally after a big snow we’d go sledding in the mountains, but Emma has one foot in a cast that can’t get wet, and she can’t climb snowy hills anyway. Broken fifth metatarsal, nothing serious. And we’ve got carnies in the driveway, and I’m afraid to leave the house unguarded while they’re here. (Just kidding, they’ve been good courtesy parkers).

So instead of karate, hiking, biking, and sledding, we’re forced to some sedentary activities like cheap Tuesday night movies and Tucson Roller Derby.

The ladies of TRD put on a good show Saturday and now Emma is sporting a cast covered with the autographs of roller derby queens, which is just extremely cool. Not everyone has the autograph of Bev Rage, Furious Oxide, Pinky McLovin, Hellbent Betty, Zippy’s Takeout, Dirty Duchess, Blanka Trohl, and others on their foot.

The breaking of the metatarsal also means we’re staying home for a little while. So, it’s time to clean up the inbox and respond to various inquiries. Yesterday, blog reader Vernon wrote to me about solar panels:

Rich, it seems that I get more real world data from your blog than most ‘data’ sources… Have you ever logged hour-by-hour amp output from your 230 W solar system under ideal conditions? I see your daily totals and they seem well below the system theoreticals … Thanks!

I often watch real-time amp-hour output from the panels and I’ve found that theoretical output is not very useful in the real world. There is huge variation depending on sun angle, time of year, time of day, cloudiness, dust on the panels, and shading from trees. There’s also some loss inherent in the wiring. As a result, on a sunny day at noon we might generate as little as 8 amps, and as much as 12 amps.

The rest of the day the output will be considerably less. In December, even on a clear day, output will generally run less than 3 amps until 9 a.m., and after 3 p.m. Thus, on a clear winter day we might generate just 25 amp-hours per day. On a partly-cloudy day, that can be cut to as little as 15-20 amp-hours, which is not much at all.

But under “ideal conditions,” we can generate quite a lot more. In late June or early July with full sun and 16-hour northern daylight, we could certainly produce more than 60 amp-hours per day.

We’ve never been able to measure our true total potential capability because, ironically, you generally need the least power in summer when it is most easily generated. Thus, our batteries are always full by 2 or 3 p.m. in the summer. Once the batteries begin to reach full charge, the system stops absorbing power and we have no way to determine accurately how much more power we might have been able to store.

Winter is the relevant challenge. That’s when you have short days, low sun angle, and much higher power consumption due to increased furnace and light requirements. It takes a powerful solar charging system and good weather conditions, to generate and store enough power to make up a typical day’s use.

It is for this reason that I recommend serious boondockers go for much more panel capability than the standard 55-watt installed as part of the Airstream “solar package.” You want to have the power to get through a couple of partly-cloudy winter days if you camp during that season. Having tilting capability on the panels will also boost power production considerably, but this is difficult to implement on an Airstream. The best way to look at it is that solar generally just makes your batteries seem bigger.

The other piece of the solar equation is the capability of your solar panel controller. Most solar controller incorporate good charging, so that when you have sun the batteries can enjoy the maximum capacity available. However, when you go plug in (whether to campground power or a generator) your factory-installed power converter kicks in, and those are often pathetically bad at recharging batteries. Read about our experience here. It makes sense to replace the factory converter/charger with a better 3-stage charger if you are going to use a generator to top off your batteries in addition to solar.

Jan 09 2010

Battery lesson

Reluctant to head back to home base quite yet, we have stopped in Quartzsite AZ for a few days of free camping in the desert. We’ve been camped at the BLM’s “Roadrunner” area, which is about five miles south of the town. This is classic boondocking, no services at all, no established campsites, and no fees. The lack of amenities is balanced against the feeling of freedom that comes with staking out a little patch of gravelly desert and just enjoying the simpler pleasures of life.

However, sometimes reality intrudes on our attempts to “get away from it all.” Last night I noticed that the Tri-Metric battery monitor was reporting strangely low voltage in our batteries, despite having used just 33 amp-hours of our total power reserve. That’s about 15% of the theoretical power available. Not long after, the voltage dropped to 10.8 volts, the lights began to dim, and I realized we had a serious problem with our batteries.

Around 9 p.m., the trailer was effectively dead. No power means no lights, water pump, or heat from the furnace. Eleanor and I were outside in the dark examining our battery bank by flashlight. We have a bank of four Optima “blue top” Absorbed Glass Matt (AGM) 12v batteries. We tried disconnecting each battery and checking voltage, hoping to isolate one battery with a problem, but they all reported the same voltage. At that point we decided to reconnect all the batteries, and limp through the night without any heat.

By reducing the power load to the small amount required to maintain the refrigerator’s circuit board and a few other “parasitic” draws (radio memory, propane leak detector, etc.), the voltage popped back up to 12.2. We all piled into one bed and stayed pretty warm, even though the trailer dropped to 46 degrees.

In the morning we hitched up and towed directly to Solar Bill’s, one of three solar installers in Quartzsite. Solar Bill’s is a fixture in Q, having been in the same location for 22 years. The guys did a load test on the batteries and found that two of them were dead as a doorknob. The other two were fine, despite having been installed at the same time.

The problem seemed to stem from our wiring. Our batteries should have been wired in parallel. As it turned out, they were wired in two banks of two, in such a way that one bank took all the load while the second bank was basically just coasting. That mistake contributed to the short life of the Optimas. They lasted 3.5 years when they should have had twice that lifespan.

Although two of the batteries are still good, the recommendation with batteries is to replace them all at the same time. This meant the two good batteries would also need replacement, an expensive procedure. Solar Bill didn’t like the choice of four 12-volt Optimas, so he suggested 6v golf cart batteries, but they wouldn’t fit.

After weighing several options, the best choice overall was to remove all four Optimas and replace them with one huge Lifeline GPL-4D. This eliminated the wiring issue and freed up our forward battery box for other uses (like tool storage). The “supercell” sits in the forward storage compartment under our bed, in the space formerly occupied by two of the Optimas.

As a bonus, the Lifeline weighs about 40 pounds less than the batteries it replaced, with a theoretical power capacity about the same. The two used-but-good Optimas will go to the Caravel, thus doubling the power available in that trailer, and we’ll have one Optima (from the Caravel) left over for future use.

But this has made for a very expensive week. Four tires, and now a replacement battery. I was happy with our relatively low maintenance expense in 2009, but so far in 2010 we’ve almost blown the budget for the year … and we are still awaiting the repair or replacement of our catalytic heater. On the positive side, it seems like we’ve dealt with a lot of the big-ticket items, so perhaps the rest of the year will go well.

Jan 06 2010

Lake Cahuilla County Recreation Area

We are still wandering the Sonoran Desert, rather slowly and without much mileage, which is a good way to go. There are many subtle pleasures of the desert, and a primary one is taking the luxury of ignoring time and society while picking up a lot of dust on your boots. So we’ve hiked and explored, cooked dinner over an open fire, watched moonrise, and many other completely inconsequential things that encourage a relaxing of the spirit. That’s a good vacation.

However, with the holidays behind us, the world is once again getting to work and so I am being swept up in the tide of obligations once again, ready or not. Business will take us further down the road before we return to home base.

Dan and Marlene, our friends at Mali Mish, blogged about a nice park near the Palm Springs area. We’ve avoided that area in the past because of the prevalence of overpriced, snobbish (“Class A Motorhomes only”), and age-limited commercial campgrounds. But it turns out that in nearby La Quinta there is a fine county park up by the foothills, called Lake Cahuilla County Recreation Area.

I can second Dan and Marlene’s assertion that Lake Cahuilla is a fine place to stay while you’re in that area. The “lake” is actually rather small, calm, and artificial (it’s a reservoir). Swimming is not allowed. But the scene is very pleasant and the campground is friendly. Sunsets, as we discovered, can be spectacular. (Water and electric sites seem to be unaffected by the larger California state budget crisis. Still $22.)

In the previous blog I mentioned that it was time to do something about our repeated tire problems. The solution I chose, based on recommendations of people who have a lot of experience with Airstream tires, was to switch to Michelin LTX M/S tires, specifically the LT235-75/R15. We took a look at all five tires (including the spare) and the tally was two bad tires (broken internal belts), one questionable tire, and two good ones (the Carlisles we installed last September). None of them, by the way, had been patched.

The Michelins are considerably beefier than the Load Range D “Special Trailer” tires they replaced, with deeper tread and much more durable construction. They are Load Range C, but don’t get alarmed by that. The load rating for each tire is 1,985 pounds at 50 psi, which equals 7,940 pounds of total weight-carrying capacity. We never run that heavy and we use tire pressure monitors to ensure that we stay at optimum pressure.

The downside, of course, is that this is a monstrously expensive experiment. The bottom line was about $700 with installation, balancing, new high-pressure stems, California environmental fees, and tax. If the tires last two years without premature failure, I’ll be money ahead compared to the amount I spend on replacement ST tires, not to mention the hassle. I’m told the Michelins will wear longer in addition to being more resistance to belt failures.

A lot of people have tried going to a 16″ Michelin XPS Rib tire, and I considered it as well. But the Michelin LTX allowed me to avoid changing the wheel rims, which cut the cost of switching considerably. They also fit better in the Airstream wheel well. Whether this change will solve the problem of the constantly-failing ST tires remains to be seen. I’ll report as we go. [UPDATE April 2015: I’ve had these tires for over five years and over 40,000 miles. Not one problem.]

While we had the wheels off, we had the opportunity for a brake check, too. The Kodiak disc ceramic brake pads were, as always, wearing more on the outer pad than the inner, and it was time for replacement. It has been a year since the last wheel bearing re-pack as well, so I decided to plunge in and get it all done at once. It has been an expensive service stop, but adding up everything we did in 2009 and this early 2010 session, we are still within annual budget we set for service and maintenance when we were full-timing ($2,000 per year).

Jan 03 2010

The sinking Dutchman

Our plan for the day was to go hike out in the desert somewhere, with Alex and Charon. But along the way we spotted a dejected man walking along the road with his thumb out. He didn’t look like the typical hitchhiker, but rather like someone whose car had broken down along the road and was walking out for help. So we stopped to get the story.

Turned out he was a European living in San Diego, and he’d bought an old Subaru a few weeks before. He’d decided to take it out into the desert to try driving on the sandy washes and 4WD roads, but he wasn’t very good at it. He got a mile or two before crashing into a sandstone wall. According to him, the car was “stuck against a wall.”

Getting a tow truck out to this part of the desert and two miles down a 4WD road is not something you want to do. Not only might it take a few days to get assistance, the cost of the tow could easily exceed the value of a 1998 Subaru.

We took our car out to the accident site and found the car kissing the stone and sunk into deep sand. It had a mangled front right fender but otherwise was in good condition. We easily freed the car from the deep sand and took a look at the damage. The engine air filter canister was crushed against the tire, making steering impossible. The front of the car’s frame was bent, and the fender, bumper, and foglight were a total loss.

The nice thing about working on a wrecked car is that you don’t have to be particularly careful about how you remove parts. Since my toolbag was back at the Airstream, our tools were a Leatherman and the car’s scissors jack. It’s amazing what you can do with those two items. Alex cut away big chunks of the plastic inner wheelwell and together we bent the bumper, fender, and air filter canister out of the way.

The tire was still rubbing at this point, so we swapped the wheel for the temporary “donut” spare, which takes less space in the wheelwell, and — ta-da! — the car was sort of drivable. Our Dutchman backed the car down the wash a few hundred feet, stalling the engine five times and scraping the undamaged side of the car against sandstone as he went. He wasn’t a very good driver. When we left, he was consulting his maps to figure out how to drive this wreck back to San Diego without exceeding 50 MPH or turning left.

Now, this episode gives me a chance to talk about desert survival. By making a few simple mistakes, you can turn a simple problem into a life-threatening emergency. We saw a lot of those mistakes today. First off, the driver had a couple gallons of water in the car — smart move. But when he went hiking two miles through the desert to seek help, he didn’t take the water. He left it in the car! Needless to say, it doesn’t do any good there.

Second, he wasn’t aware of his location. When we found him, he was walking east. In that direction, it was 25 miles to the first services of any kind. He never would have made it. If he had headed west, he would have encountered services in less than five miles, and a group of campers in about two miles. He had maps with him, but he either didn’t consult them before he set out, or he didn’t understand them. They were also left in the car.

Third, he disregarded a simple idea: stay with the car. The wash he was in was a popular route, on Sunday of a holiday weekend. Someone was bound to come by in an hour or two. In fact, while we were there, two other cars came through the spot. Any of them could have given him a ride to assistance, which would have been a lot wiser than going for a walk in the wrong direction without water. The car also would provide shelter from the sun if needed.

Fourth, he was inexperienced and driving alone on a 4WD road. Bad idea.

Fifth, he was off-roading in a Subaru Outback. I’ve owned a couple of Subarus. The 1998 Outback has a great All-Wheel Drive system, but only 7.3 inches of ground clearance. That’s not enough for the kind of deep sand and ruts found on these washes. The key on that sort of road is not just traction, but high clearance. We go out with 10.9 inches of ground clearance and there are still a lot of sections I won’t attempt.

Saving this guy’s bacon put us an hour behind schedule, but we still had time to drive out on another 4WD road and enjoy lunch high up on a sandstone ledge. An easy mile-long hike followed, up to the Wind Caves that we like to explore. I think we had a much better day than the soon-to-be-ex-Subaru owner.

Sadly, this is our last day of R&R. We’ve got to get on the road Monday, but not heading home yet. Our travels will continue for at least 4-5 more days.

Jan 01 2010

Desert vacation

It is 2010 and good things lie ahead.

Christmas was a quiet success in our household. Since we are thousands of miles from our extended family, we used Internet technology on Christmas morning to videoconference with my parents and brother while we opened gifts. I thought it would seem strange to have the family on a laptop screen, perched atop a box in the living room but it was surprisingly like having them there with us. This may become a Christmas tradition in homes across America, replacing the horror of holiday air travel for many.

Just two days after Christmas, we took off to California for some desert camping. Almost every trip I take is a working trip, but once in a while I like to try to avoid work and just do the stuff that normal people do in a campground, and the hope was that this quiet week between Christmas and New Year’s Day would allow that.

On the way we stopped in Yuma to visit with Barb & Joe of MobileInternetSatellite. A couple of years ago I bought a used Hughes satellite Internet system from my friends Brian and Leigh, who had recently completed two years of full-timing. The price was right and I thought I might use it for an extended trip into Mexico. But that was before the Mexican Drug War ramped up. We found other things to do and the satellite dish gathered dust in our storage closet. With the smaller Mercedes as tow vehicle, carting around the satellite dish became less practical and I decided to try to sell it through Barb & Joe.

Unfortunately, satellite dishes are being replaced by cellular aircards, which for most people provide faster, cheaper, and highly portable Internet. The only folks who need satellite are those who spend lots of time parked beyond the reach of cellular networks and commercial wifi hotspots. So selling a dish is pretty tough these days, even one that comes complete with all the accessories.

Now that we are out in the desert, we are experiencing the sort of quiet and vigorous life we have come to like. There are hikes up palm canyons by day, and the soft sounds of birds each morning (Gambel’s Quail and hummingbirds in particular). In the evening there is the smell of tamarisk wood fires. (Since tamarisk is an unwanted invasive species, cutting it down is often encouraged.)

It’s a little cool once the sun slips behind the mountains at about 4 p.m., but shortly after sunset we have the compensation of a startlingly large and brilliant full moon rising. People in the campground are wrapping up in warm clothes and spending the night outside regardless of the temperature, which as been bottoming out in the 40s.With clear skies most of the time, nights have been bright enough that we don’t need a flashlight to walk around. When there were clouds on Wednesday, they just added to the drama of the surrounding mountains.

Little desert-related surprises come to those who watch, like the tarantula that wandered by our campsite yesterday. (Eleanor got some video of that.) So we are making no plans and letting each day come. Most importantly, I’m not getting any business phone calls and virtually no emails of importance, so the computer is off except for an hour in the morning.

I have been getting more of the “how does that car tow that big Airstream” comments this week than usual. Everyone seems to be shocked when they see the Mercedes parked in front of the Airstream. I’ll answer questions for anyone who is really interested, but most people just boggle at the sight and then wander off. I don’t think they really care to learn the details; they’d rather just enjoy the novelty of it.

The one big frustration of the week has been, once again, a tire failure on the Airstream. One of the older tires (date code August 2008) is showing a worn spot, approximately round and rather uneven, that suggests yet another internal steel belt has broken. It will need replacement shortly.

Well, that’s the final straw. I have not been able to wear out a set of tires since 2006, because they keep failing internally. We replaced two in September for the same reason, and many others over the past few years. We’ve been using the factory-recommended Goodyear Marathons (designated “ST” for Special Trailer use, load range D) as well as similar tires by Carlisle, Trailer King, and TowMax. We have had, frankly, a completely unacceptable experience, with multiple failures over the past three years. It’s 2010 and time to try something different.

I didn’t come to this conclusion lightly. We have eliminated as many possible causes of tire failure as possible. We tow at 65 MH or less, we’ve weighed the trailer, we balance the tires and also use Centramatic wheel balancers. We use a tire pressure monitoring system to ensure proper inflation at all times. We’ve aligned the axles of the trailer annually, most recently in September. I inspect the tires at every fuel stop. Still, the treads keep suffering rapid tire wear in localized spots.

I’m going to toss all the tires and try a different tire design (not an ST) very soon. Right now I’m gathering consensus from some respected experts, and comparing various alternatives. Some people swear by Load Range E tires, others use LT (Light Truck) tires, and some say that bias-ply designs are the answer. Some think a particular brand makes the difference. What I find interesting is that so many people have trouble with ST tires that are supposedly designed for trailer use, and yet have more luck with tires that aren’t specifically designed for trailers. As one experienced Airstream dealer said to me this week, “ST just means it’s a tire that isn’t good enough for passenger use!”

I’ll report further on the tires we choose, and our experience with them, a bit later. With a little effort and a little luck, I won’t be talking about tires much in 2010 … I hope.