What you can do with solar

RoyB wrote:
We are sort of in the same boat as PHIL PNICHOLS. Our camping off the power grid works just great running all of our needs from our increased battery bank and re-charging the next morning using smart mode technology and the 2KW quiet Honda generator for three hours. We consistently consume around 300WATTS or so during the one day/night run off the batteries. Being self-sustained for the one day/night run off the batteries is not an easy task and requires some planning for longer stays back in the woods.

This fits in rather nice with 99% of places we go to here on the East side of the US where most everywhere has some sort of generator run time restrictions in place.

With the generator I too have no problems whatsoever returning my battery banks back to their 90% charge state rain or shine with the three hours generator run time each day...

Having done this for the past five or more years we have become most successful camping off the power grids. Adding solar panels would be icing on the cake for us and with some planning on the short comings of most small solar panel installs. The main problem we are experiencing with our solar panel planning is having a large battery bank already charged up and using the solar panels to put back power we have pulled from the banks in the 6-8 hours SUN window each day and not have to run the generator the next morning. With the generator run time restrictions in place at most of the places we go to we will have to know by 4:30 each day whether or not we will have our 90% battery charge state for the night run off the batteries. This window gives me enough time to run the generator for three hours if the solar panels are not doing their job. Not having a 90% battery charge state for the night run is NOT an option for us.

I presently don't see any way we would ever be without having our generator on-hand however as small solar panels installs up to 360WATTS or so do not gaurentee a good 90% battery re-charge each day before starting your night time run from the batteries.

I'm sure once I start playing with the solar panels this exercise will become easier to do.

Roy Ken

300 watts per 24 hour period at 12 V is 50 amp hours pulled from the battery. I would look at getting 50 to 75 amp hours back during the day, in a 5 or 6 hour period. If you camp in the winter, you'll need more wattage of panels, but getting an average of 10 amps to 15 amps an hour for 5 hours a day with some portable panels with some pointing and aiming 2 or 3x a day at the sun. My guess is that would work out to 180 to 270 watts needed of portable solar panel available to get the job done. When working with portable solar, it's amps of charging from panels that count, not so much voltage.

Check out Solar Blvd, get a couple of 140W 12v panels and a 20 Amp PWM charge controller.

280 watts solar panel, 140w each from Solar Blvd.

And a cheap 12 V 20 amp charge controller.



or a pricier Morningstar
Sunsaver 1v 20A charge controller

Another option, add some hinges and a window latch to make it portable and folding.

200 watt kit.

My guess is that this last item should get you 11 to 12 amps an hour with that PWM Charge Controller for close to 5 or 6 hours in the summer, a bit less in the winter. Run 12 gauge strand wire from the portable panels to the batteries, and keep your feet of run at 25 feet or less, or go to 10 gauge strand wire to minimize losses to less than 1%, and you should be good to go. That's $1.25 a watt with a controller! Watch the amps at the lower of the two numbers, and count on a 10% loss below that. ie 12 amps works out to about 10.8 to 11 amps out of the charge controller.
Let the Honda Eu2000i handle the first hour of heavy charging, first thing in the morning, and then let the solar panels top things off if it's going to be a sunny day. If no sun, then run the genny for 2 more hours before quiet time.