Outlets Off while Boonedocking

No Rick, I am still here! I am both enjoying reading the responses and learning as I read. I greatly appreciate all of the responses, thank you! It is a much bettwr way to learn then trial and error would be.2

pianotuna wrote:
So far as I am aware some panels have 3 bypass diodes (one per string). Others may have only one diode per panel.

Don .... now I'm curious.

A solar panel array with it's panels in parallel with each other could of course still maintain the array's terminal output voltage (but with less total current output capability) if a panel became shaded - using only diodes within/around each panel to somehow isolate it whenever shaded.

I guess I need to see some kind of schematic or circuit diagram as to how - electrically - only a diode arrangement could keep a shaded solar panel from lowering the array's terminal output voltage if all of the array's solar panels are in series with each other?

Maybe panels in series do experience a voltage drop whenever one or more panels are shaded, but solar controllers have a large enough input voltage range to deal with it?

It "seems like", for instance, that a bunch of 24 volt panels in parallel always putting out 24 volts - even with some panels being shaded - into the controller would be a superior arrangement. :h

pianotuna wrote:
Hi Mr Wizard,

Imarine is selling the PT-100 for 700.

https://www.solarblvd.com/products/ecosolargy-230-watt-24-volt-solar-panel/ $72 each $504 for seven totaling 1610 watts. If there is room you could add one more--so $576 gets you to 1840 watts.

That leaves about $700 to 800 for other materials.

The Magnum input voltage for a 12 volt output is a maximum of 187 volts. So the entire string of seven could be in series (168 volts).

64" x 39" x 130 lbs. x 7 panels = 121 sq. ft. and 910 lbs.

2000 watt generator = 1.6 sq. ft. and 46 lbs.

Looks like I'm running a generator.

Hi,

They weigh 41.9 lbs each.

My daily cost for purchase of generator(s) has been $2.45 per day since 2009. The daily cost for solar is $0.66 per day since 2009. I actually bought them in 2005 which means cost has been $0.39 per day.

Cost to keep the solar running $0

Cost to keep the generator running 451 liters of fuel @ 0.979 per liter = $441.53 plus oil changes plus motor tune up.

atwowheelguy wrote:


64" x 39" x 130 lbs. x 7 panels = 121 sq. ft. and 910 lbs.

2000 watt generator = 1.6 sq. ft. and 46 lbs.

Looks like I'm running a generator.

Hi Phil,

My understanding is that for each cell (or string) that drops out and is bypassed the voltage will drop.

My system is nominally 33 volts, so I get some charging early in the day and some past actual sunset.

That is one reason it has been so hard for me to make the decision to replace what I have. It works extremely well and does exactly what I planned it to do. Just not enough wattage for full time.

pnichols wrote:
It "seems like", for instance, that a bunch of 24 volt panels in parallel always putting out 24 volts - even with some panels being shaded - into the controller would be a superior arrangement. :h

pianotuna wrote:
Hi,

They weigh 41.9 lbs each.

My daily cost for purchase of generator(s) has been $2.45 per day since 2009. The daily cost for solar is $0.66 per day since 2009. I actually bought them in 2005 which means cost has been $0.39 per day.

Cost to keep the solar running $0

Cost to keep the generator running 451 liters of fuel @ 0.979 per liter = $441.53 plus oil changes plus motor tune up.

atwowheelguy wrote:


64" x 39" x 130 lbs. x 7 panels = 121 sq. ft. and 910 lbs.

2000 watt generator = 1.6 sq. ft. and 46 lbs.

Looks like I'm running a generator.

Sorry I got the weight wrong. The web site says 130 pounds on one tab and 41.9 pounds on the other tab. Unnecessary confusion there. My camper has 174 sq. ft. of roof area, much of which is occupied by an air conditioner, two vent fan ports, refrigerator vent, sky light, plumbing vents and antennas, all at the most inconvenient places. No way could I occupy 70% of that entire roof space with solar panels even at 293 pounds. Point is that sometimes the all-solar-power solution is just not practical for some.

If I were a penny counter, I would never have purchased a camper to tow around the country at 10 mpg. Hotels are cheaper. The pennies are not the end game. Yes, a silent campsite all the time would be great. I just can't see how it would be feasible for everyone.

If you want to bypass all of the techie talk:

You can use your propane stove to heat water and use a pourover to make really good coffee.

Another good tip? LED lighting. It makes the best use of limited battery capacity. That way if it's still dark when you get up to make your coffee, you can see to light the burner.

You can even combine both sides of the argument here. Buy a generator with a battery starting system. Get a solar charger to keep the generator starting battery topped off.

Last choice would be to do things the way I used to when boondocking: sleep when it's dark, and explore when its not. I am too old and crotchety these days, so I usually Wallydock for an overnighter any more.

DryCreek wrote:
If you want to bypass all of the techie talk:

You can use your propane stove to heat water and use a pourover to make really good coffee.

Another good tip? LED lighting. It makes the best use of limited battery capacity. That way if it's still dark when you get up to make your coffee, you can see to light the burner.

You can even combine both sides of the argument here. Buy a generator with a battery starting system. Get a solar charger to keep the generator starting battery topped off.

Last choice would be to do things the way I used to when boondocking: sleep when it's dark, and explore when its not. I am too old and crotchety these days, so I usually Wallydock for an overnighter any more.

^^ Good suggestions there. When I discovered that one 12V battery wouldn't carry a couple of incandescent lights for a few hours and then the furnace fan all night, I added a second 12V battery and replaced the lights with LEDs.

Thanks everyone. I need an outlet for a medical device when I sleep. I had hoped for the best. I greatly appreciate your help!

LongOverDue wrote:
Thanks everyone. I need an outlet for a medical device when I sleep. I had hoped for the best. I greatly appreciate your help!

Simplest solution is to get a 12V powered machine. (Edit: Apparently some DC powered machines won't run the humidifier, so that may not work.) Otherwise, there are some answers here: https://www.guaranty.com/blog/what-size-inverter-do-i-need-to-run-my-cpap-1