Solar Powering the Airhead!

Pat Anderson · Posted: Mon Sep 13, 2010 8:49 am Post subject: Solar Powering the Airhead!

This weekend's project (along with cutting in the new hatch below the motorwell) was to get the Airhead running solely on solar power. We originally tried a Nicro Solar Vent (5 years ago) but it would not stay charged.

This is a 15 watt PV panel from Harbor Freight Tools.

The Solar Controller is also from Harbor Freight. The connections are for the PV panel, the battery (one of the Optima Bluetops that were the original house batteries) and the load, which in this case is the 80ma fan in the Airhead.

The PV panel is mounted on a piece of 1/4" Starboard from Tap Plastics in Bellevue, WA. The Starboard has 4 rubber feet and is held in place (for now) by straps. The lead runs (for now) through the bathroom window. Eventually if all works as planned, the Starboard base will be permanently mounted in place and the lead will come in through a clam shell in cabin wall.

The PV panel will run the fan with even a little amount of light without the battery connected, but the PV panel and controller keep the battery charged (so far so good on that one) so the fan runs on the PV when there is light and on the battery when there isn't. This ought to work great even in the cloudy PNW...

Captains Cat · Posted: Mon Sep 13, 2010 9:36 am Post subject:

Scary Pat! You're getting awfully good at this DIY boat stuff!! Laughing

Next thing you know, Patty will let you use something sharp! Mr. Green

Charlie

Casey · Posted: Mon Sep 13, 2010 9:37 am Post subject:

Pat,

I hope you guy's realize ... with the recent galley remodel, this project, and other related job's, you are putting your reputation of an ALL THUMBS variety of handyman in Real jeopardy.[i]

Best,
Casey

Sneaks · Posted: Mon Sep 13, 2010 10:07 am Post subject:

Gentlemen, you have to realize that Pat was raised in a disfunctional environment where blue collar trades were an anethma and he was actively discouraged if he did anything other than use his considerable brain power. He developed FUD syndrome and only now has he been able to break loose from that debilitating disease. He has shed the fear and uncertainty that leads to defeat and is blossoming, albeit late in life, encouraged by the free flashlight offers at Harbor Freight.

I wonder how many Harbor Freight flashlights he now owns?

Nephew, I salute you. It appears to be a good job. I give you an A on placement, B+ on wiring skills. Can't wait to see the results of your hatch project.

Regards to Patty

Don

Captains Cat · Posted: Mon Sep 13, 2010 10:28 am Post subject:

Sea Wolf · Posted: Mon Sep 13, 2010 2:06 pm Post subject:

Pat-

First of all,, congratulations on your developing DIY skills! Why says experienced barristers can learn new tricks?!?

Second on your wiring planning:

"Eventually if all works as planned, the Starboard base will be permanently mounted in place and the lead will come in through a clam shell in cabin wall."

You might consider drilling a small hole in the cabin wall just under the roof lip overlap above the airhead. Add a rubber grommet around the wire, and use marine latex calking compound to seal the opening on both the outside and inside to prevent water intrusion.

You'll have the same seal problem with the clamshell, but using the roof lip overlap eliminates the clamshell, and puts the opening up as high as you can get it without going down directly through the roof.

I'd also use a nylon wire strap down fitting with the stainless screw fitted down into the void between the lip and the cabin wall to secure the wire from the PV unit, to prevent snagging and pulling out of the wire.

Another thought is that you might actually drill two holes, one in the roof top above the void between the lip and the cabin wall, then another as before. This way, the wire goes directly down through a safe place in the roof (no leaks), then through the cabin wall, and doesn't have to loop around the lip overhang, and is much neater. Seal both holes as before. Whether this will work depends on how much room you've got to work with between the lip and cabin wall, etc.

Maybe someone else has a better idea on the seal issue, but the grommet/latex system has worked for me. I have several up under the front windshield hood.

Good Luck!

Joe. Teeth

Casey · Posted: Mon Sep 13, 2010 2:47 pm Post subject:

All,

... A Barrister learning new tricks; I Love it!

And did someone say Harbor Freight was giving out free flashlights?

Hmmmm......

Best,

Casey

hardee · Posted: Mon Sep 13, 2010 3:03 pm Post subject:

Pat,

Looks like you are getting ready to move aboard. This is me Mr. Green

At the Sequim Bay CBGT, Greg aboard Aurelia had a solar panel set up. I talking with him he found some panels that produce more power (maybe 2X) but had the same footprint as the Harbor Freight ones. Might be able to double your power and run that electric vibrator on the recliner too Very Happy

Might be worth chatting with him re the solar stuff.

By the way, I'm getting close to needing a wheel bearing do. Mind if I stop by while you are preping yours for Lake Powell Twisted Evil

Harvey
SleepyC Moon

Sea Wolf · Posted: Mon Sep 13, 2010 3:56 pm Post subject:

I have a small 5 watt solar panel to tickle charge my Sea Ray, but have it on the back side of the boat locker because it gets more sun there, since I'm in a covered space.

However, it only charges the port motor (two) of the batteries, since the other two are isolated (starboard motor, windlass).

I've also get a new 50 watt panel, but will probably mount it on the boat somewhere, so it can go out with me when cruising. Will have to design a distribution system to allow all four batteries to be charged by the larger panel.

Joe. Teeth

sjboysen · Posted: Mon Sep 13, 2010 3:59 pm Post subject:

Pat,

Nice Job! Send me some more information about this unit, I think being able to offer something similar to this would be advantageous and I would like to research it further.

Again nice and keep up the good work.

Scott

Sea Wolf · Posted: Mon Sep 13, 2010 4:31 pm Post subject:

I have a small 5 watt solar panel to tickle charge my Sea Ray, but have it on the back side of the boat locker because it gets more sun there, since I'm in a covered space.

However, it only charges the port motor (two) of the batteries, since the other two are isolated (starboard motor, windlass).

I've also get a new 50 watt panel, but will probably mount it on the boat somewhere, so it can go out with me when cruising. Will have to design a distribution system to allow all four batteries to be charged by the larger panel.

Joe. Teeth

Pat Anderson · Posted: Tue Sep 14, 2010 8:39 am Post subject:

Thanks, Scott. There may be more suitable panels out there, but this one was cheap. This panel was $70, here is the link. You also need the controller, which is another $30. I am carrying around a coupon in my wallet for at 45 watt panel for $150, but it is three times larger (literally, three 15 watt panels in a larger frame), so would cover the cabin roof, and I can't do that because that is where the dinghy and/or kayaks go! I am thinking about the 45 watt panel for the fifth wheel, actually I would like an even bigger one. But Harvey said somebody has a line on panels the same size the output twice as much power, so there is a bit more investigation to do. But I will keep you in the loop as this idea develops!

Pat Anderson · Posted: Tue Sep 14, 2010 8:46 am Post subject:

Indeed, you get a free 9 LED flashlight just for visiting the store, which is pretty amazing. It really is a big boys toy store. However, no free flashlights with this project, as the big brown truck brought everything from the Harbor Freight web site. The shipping charge was more than offset by the time and convenience!

localboy · Posted: Tue Sep 14, 2010 10:30 am Post subject:

I'll be interested in how that solar panel survives the ravages of salt water. HF is full of cheap tools/equipment. But the key word is cheap vs inexpensive. It may do just fine and you didn't mortgage the house buying it.

Aurelia · Posted: Tue Sep 14, 2010 12:58 pm Post subject:

Pat,

In response to your question, we ended up using this panel and charge controller. They are both very sturdy and designed for bad environments. I did a google product search on these two items and bought them from different vendors over the summer. I plan to add another panel in the future to my exising radar arch mount.

http://www.solartechpower.com/chargerssw/SG4.html

http://www.solartechpower.com/solarpanelsw/solar_panel_30WATT.html

Most of the panels sold are of the Amorphous type which work fine but are not very energy dense. A 15 watt panel is typically 42x16 or 35x11 but would only need to be about half the size if using multi/poly crystaline cells.
We use a 30watt panel that is 26x16 and pushes nearly 2 amps into our house batteries or into the Pudgy's battery. We use it to keep the Pudgy topped off when sitting at the marina as well.

You can see it mounted and facing forward in this pic:

http://www.c-brats.com/modules.php?set_albumName=Sequim-Bay-2010&id=DSCN1012_edited_1&op=modload&name=gallery&file=index&include=view_photo.php

And rearward in this one:

http://www.c-brats.com/modules.php?set_albumName=Sequim-Bay-2010&id=DSCN0984&op=modload&name=gallery&file=index&include=view_photo.php

It is mounted so we can tilt it forward or back in a few seconds with a piece of shockcord and a clip on the frame. The wiring is portable and window accessed like yours right now but I will wire it through the radar arch in the next couple of months but keep a pigtail up there for rooftop or boatside pudgy charging as well.

It makes a significant difference providing about 10-20+ guaranteed amp hours of free power per day and roughly offsets our use of the fridge. Adding a second panel will easily add another day to our anchoring although we can go four days now without need for other power.

Greg