Solar Question

[Warren Wilson]

I have a Boler that is running entirely on solar power. It is not wired to take any charge from the tow vehicle.

The brain is the solar charge controller: connected to the panel, the battery and the "consumer" side.

Two questions:

1. Can I simply attach my regular old battery charger (which I use for other batteries when they need a top-up: car, truck, quad) without disconnecting the system?

2. I have pondered permanently attaching the panel to the roof of the Boler so that it charges when I am underway. How do the pluses and minuses work out on this notion?

[David B.]

Warren, I have read, and spoken to a technition at our local solar company about this very thing. He stated that the solar controller will monitor what is needed and adjust to each situation. We are connected to the tow vehicles 12 volt system, and we use a battery charger when needed to top off batteries whenever necessary. No problems in 6 years.
Dave & Paula

[Paul Braun]

Having a solar panel on your roof is a great solution to charging your batteries while traveling. However there are a few trade offs. For me, the big one is the inability to angle the panel to obtain more sun when parked, beside the angle is the placement, you maybe in a forested area with much tree cover and unable to get any sun.

As you may have discovered a solar panel is picky, they want it all. Sun, that is. They cannot handle any part of them covered by shade, something as small as a bare tree branch will end your charging. Portability can give you the opportunity to reach some sun.

A second issue is properly securing the panel to your roof. It is done a lot but it must be done properly.

[Warren Wilson]

Thanks for the replies -- it's reassuring to know that I can "fill up" the battery with some generator energy when needed.

And, Paul, I am actually pondering putting a second panel on the roof to get some charge when driving and keep the "main" panel to move about and point at the sun when parked.

I'm now curious about any conflicts between the two panels if I simply wire both into the "input' side of the charge controller.

[steve dunham]

If your tow vehicle has a 12 VDC charge circuit going to the 7 pin receptacle on the vehicle , you can use that power to charge your battery while driving. In the summer when it's hot most people try to park their trailer in the shade to keep their trailer cool but that renders the roof top solar basically useless .
Except for the possibility of theft , I much prefer a portable solar panel which allows me to aim the panel to get the maximum output..
We have a 100 watt portable solar panel which I set up in a sunny location and 3 to 4 hours later my battery is fully charged.
Having a fixed solar panel on the roof and a portable would be the best solution but is more expensive and may give you more solar than you need.

[Mike Magee]

No conflicts, except you'd better make sure your controller is rated for the combined peak amps of the panels.

[Warren Wilson]

Thanks guys: such nice clear, practical responses.

Steve: thanks. I do have a 7-pin connector from the tow vehicle, yet I was told by the seller that it would not charge the system when towing. I should see if I can use my multi-meter to test that assertion. Certainly there will be output from the tow vehicle. (He didn't seem very savvy about the system, I have to say).

Mike: thanks -- such a practical approach: I am going to have to get some numbers on that and once again try to remember how amps, volts and watts swap sizes. I keep reminding myself that math is our friend -- just sometimes a difficult friend to manage.

One thing I really appreciate about this new-to-me Boler is that it has a convection furnace: i.e. It takes no electrical power to run, an improvement over my old Boler, which had a Suburban furnace with a fan. (Sadly, it was brand new. I installed it two days before my wife wrote the unit off on a Yukon bridge).

Which allowed us to "upgrade."

[The Minimalist]

Originally Posted by Paul Braun

...........a solar panel is picky, they want it all. Sun, that is. They cannot handle any part of them covered by shade, something as small as a bare tree branch will end your charging

This is not entirely true. It depends both on the type of solar panels you are using and their internal construction. Amorphous thin film cells will produce electricity even in shaded or cloudy conditions. On panels using monochrystalline or polychrystalline cells, how well they work in shaded conditions depends on how they are wired internally. If they are wired in straight series, if one cell is blocked from the sun, the whole panel goes down. If they are wired series-parallel, as I believe most are these days, you may lose production in one section, usually in a strip of cells, but not in the others. It is best to check with the manufacturer to determine how they are wired, and specifically ask them about shade tolerance.

I opted for the amorphous cells when I went solar, particularly because there are usually trees where we prefer to camp, and it's not unusual for the days to be cloudy/rainy. Many times the only direct sun we get is from about 9:00-10:00 AM to 2:00-3:00 PM. In the Little Joe our electrical demand is small, and we use a Group 24 Marine Deep Cycle battery. I use a manual battery charge/state monitor I built to check battery condition. Also, with the Little Joe, it's easy to orient the trailer to maximize sun exposure, should we feel the need.

Admittedly, the amorphous cells have some drawbacks, both in terms of initial efficiency and weight, but I considered our needs and typical camping conditions and determined that for our purposes the amorphous panels were the best choice; this not to mention the significantly lower cost at the time of the installation. Also, amorphous cell efficiency doesn't degrade significantly as cell temps rise, although I have not found this to be a significant factor in our application.

Note: I also have no hookup for charging from the TV

Regards,