Tag Archives: marine

The Teardrop Gets a Solar Power Upgrade

Teardrop Trail Log: September 20, 2016

MC4 solar branch connectors

After the unfortunate incident with the solar panel on our way to the Red Power Roundup, we were able to use shore power for the remainder of the trip. Disappointing, but not a show stopper. We had already determined that a single 100-watt panel was not enough for our needs, so I was planning an upgrade anyway. With a trip planned in late September, it was time to act. I ordered two new 100-watt panels, MC4 combiner connectors and additional MC4 crimp-on connectors. This would double our previous power capacity and allow for daytime use of a couple of small appliances including a crock-pot and solid-state cooler.

Aluminum bar seals leading edge to teardrop

Analysis of the incident and the remaining parts of the old panel made it clear that wind entering the leading edge had repeatedly flexed the panel causing it to fatigue and ultimately fail. It seemed to me that sealing the leading edge to the teardrop roof with a rigid mount would prevent this type of failure in the future. A trip to Home Depot secured an aluminum strip, and by drilling holes that matched the existing screw mounts, I could seal the leading panel to the teardrop skin. The leading panel then overlapped the other panel so it was also sealed to the wind.

The new panels began working immediately

Once installed, the panels began producing power immediately. Although we currently only have about 80 Amp-hours of storage, the two panels can easily replace the day’s power use with 10 to 12 amp output in full sun. Also, by adding a 300-watt inverter, we are able to run a 1 1/2 quart crock pot during the day with power to spare. The next upgrade will be a larger battery.

The Ambassador was ready for a trip to Bob Sandlin State Park.

photo of solar panels on teardrop trailer

The panels overlap like shingles

There Be Dragons …

Teardrop Trail Log: June 13, 2016

I guess I should be grateful we didn’t have more problems. If you think about it, trailering is an unlikely pastime, wherein one drags a small metal box on wheels at high speed over sometimes nasty, bumpy roads and expects everything to arrive at the same time. Then there’s the summer heat, rain, and wind — all of which can be extreme. Top it off by camping in the woods with open campfires, animal encounters and rutted trails masquerading as roads, and it’s a wonder things go as smoothly as they do. It’s a testament to the essential hopefulness and naïveté of the average camper. Certainly it describes our view of staying in the woods.

Repairing the antenna tube

Looking back, I understand our first several trips were usually trouble-free. Perhaps it was payback time. After a day of construction, rain, and detours, I thought we might have taken our lumps. As it turned out, we were just getting started. Day 2 dawned cool and overcast, and wonder of wonders, there was a Starbucks nearby. We went in and ordered, and within minutes I was in possession of the magic elixir. A Mocha. On the way back to the rig, I noticed that the antenna storage tube was askew. One of the supports had broken. Better fix it.

I decided to run our solar beer cooler while we were on the road. The day promised to be sunny, and I would have cold beer while setting up camp. Off we went through Paris, Texas, on our way to Joplin. Easy travel.

Dropping voltage

Since I was curious how much power we were generating and using with the beer cooler, I checked the voltage monitor every time we stopped. The battery voltage was falling slowly, suggesting the solar panel wasn’t keeping up, but nothing to worry about. Then during one of our stops, I noticed that the battery voltage had dropped by two volts. Not normal behavior. Considering the problem while we drove the next leg of the trip, I realized that one cell in the battery had catastrophically failed. This battery was toast.

We would have to find another. Marilyn got to work with the maps. As she plotted routes and queried the web, I mused on the rotten luck. What were the odds? Batteries don’t normally fail like this. On the other hand, it was over a year old. Maybe the battery maintainer wasn’t very good. Then, she announced her result. There was a Costco in southeast Kansas City, and going there would only take us a few miles out of our way. The camping gods had smiled.

We stopped at Costco, bought a replacement battery, and installed it in the parking lot to recover the core charge. Even so, we arrived at the Jacomo Campground by 7. Plenty of light to set up while Marilyn cooked a delicious dinner. Maybe we had finally paid our karma debt and could sail unconcerned into the adventure!

A New Battery

Marine-Style 12 Volt Outlets in Our Teardrop

Jim, July 23:

One thing we learned on our trip to Big Bend, we needed more power outlets! With two smart phones, an iPad, a laptop, two cameras and other low-voltage doodads and geegaws, the two 12-volt and two 120-volt outlets that came with the trailer were simply not enough. Multi-outlet USB chargers helped, but added to the clutter in the cabin — especially at night. Also, the existing outlets were located on the aft interior and galley walls. Not convenient for charging while reading in bed.

Galley outlets

We had been working on a friend’s tiny house, and learned that the universe of 12-volt equipment has greatly expanded in the last couple of years. The tiny house was equipped with a marine power center, and offered 120/240-volt and 12-volt service. Just what was needed while at shore or underway. We equipped the tiny house entirely with 12-volt lighting, and easily found fixtures, light bulbs and other 12-volt outlets. With all the interest in solar power the number and quality of such devices is rapidly improving, and a trip to the Amazon store yielded several marine-style USB, cigar lighter and battery monitor fixtures.

USB power outlet detail

Fortunately, the Ambassador has hollow wood-paneled walls, so expanding the existing 12-volt wiring wasn’t too difficult. I simply replaced the two 12-volt cigar outlets with double and triple-gang devices on the back wall of the cabin and galley, while adding a pair of USB outlets on the forward wall under the cabin light. The marine system is nice because the 2 or 3 position panels can accept any combination of outlets and monitoring.

Now we can read in bed while charging our iPhones and other USB and cigar-lighter-based devices. Perfect!

: Interior — looking aft

: Interior — looking forward

: Cabin light and USB power outlet

Solar Power on the Teardrop Trail

In an earlier post, we described a simple solar system for the our teardrop. With only a 15-watt capacity, we needed to upgrade and did so last year. We’ve gotten some questions about our solar power installation on the teardrop, and I wanted to share what we’ve done. This a work in progress, but during our recent Big Bend trip, we never hooked the trailer up to shore power (aka 120 volt hookups) and used solar power almost exclusively. It’s important to state our goals however, we didn’t intend to replace shore power. Instead, we wanted to extend the practical range of our trailer, making it possible to use primitive campsites for days at a time. This is where solar power can really shine (pun intended) on a small trailer.

There are several elements to a solar system. At minimum, a solar panel, a storage battery and some kind of charge controller are needed. Additions include 120/240-volt capabilities like battery chargers and inverters. Our system is almost exclusively 12-volt. With it we run lighting and have the ability to charge multiple devices such as smart phones, tablets, a laptop and digital cameras. We even have the ability to run a few high current 12-volt appliances like an electric tea kettle intermittently. Our trailer has a 7500 BTU air conditioner (this is Texas after all), but that must be run on shore power.

photo of battery, charger and charge controller

Charge controller in place

Broadly speaking, there are two types of charge controllers: Maximum Power Point Transfer (MPPT) and Pulse Width Modulation (PWM). Both have their advantages, but a PWM controller won in cost and efficiency for our particular application: hot, sunny climates and systems of 170 watts or less. An article with a more complete comparison may help with your decision.

Here’s what we ended up with:

Renogy® 100-Watt Monocrystalline Bendable Solar Panel (update: no longer available, but this panel is similar)
Renogy® 10-Amp PWM Solar Charge Controller (update: no longer available, but this controller is similar)
Interstate Group 27 Marine Deep Cycle/Starting Battery (available from Costco)
Jensen JMP-800 75-Watt Power Inverter (plugs into a 12 volt outlet for occasional use)

Fortunately, our trailer was built with dual wiring: 12 and 120-volt. There is 120-volt power in both the galley and interior, and a 12-volt outlet is available in the interior. I added a 12-volt feed into the interior cabinets to power a Ten-Tec Triton II amateur radio. Most of the installation work involved mounting the solar panel on the trailer’s roof. The charge controller was mounted in the galley storage adjacent to the battery. The trailer was already equipped with a small charger, and it charges the battery when we’re hooked up to shore power. The solar panel can be removed from the roof and located away from the trailer using an extension cord. This way, we can park the trailer in a shady spot while the panel is located in the sun. The photos show the mounting screw installation process.

: Tapping into the aluminum skin with a double-ended screw

: Re-mounting the screw with marine epoxy

Incandescent Bulb

The trailer came with 12-volt automotive light fixtures and incandescent bulbs.

LED “corn” lamp

These were replaced with LEDs resulting in a 75% power savings. As I mentioned, it is a work in progress, and I would like to add a second panel. There’s room on the roof, and that would double our capacity.

Mounting the panel

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