Solar panels. Useless or the future?

JamesBondo

House Member
Mar 3, 2012
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I have a sleep apnea machine that needs 1.5 amps (at 12volts). I love camping so i wanted to see if i could camp with my cpap for more than a few days without needing a wall charger or generator...

....i think you are thinking what i am thinking....

A SOLAR PANEL!!! What can be sweeter than having a solar panel and making free power, right?

So I went to canadian tire and bought a 25 watt solar panel for $100. In theory, i would have 2 amps of charging capability but im told to be careful because that is 2 amps in ideal conditions out in the arizona desert.

OK, I understand. YMMV, right? Buyer beware, right?

No problem. Even at 1 amp, i could recharge a 6 hour sleep with a 9 hour charge. And, Ive got almost 15 hours of daylight to get 9 hours worth of charging.

So off to my first campout i go....first night, wonderful...the next morning i get up early and put the solar panel on the battery, it charges all day until sunset..the next night, my battery goes dead just after midnight.....WTF!?!?!?!

Obviously, the solar panel isnt delivering 1 amp, ie half of its 2 amp rating.

So i go home under slept and grumpy. I pull out my multimeter. I want to do an experiment. How much current can i get from my solar panel when it is outside but not pointed directly at the sun?

Any guesses?

In my case, i measured it, and I got 0.2 amps.

Yup. Only 10% of the rated capability of the panel.

So how long will it take to recharge 1 nights use of my CPAP? My math tells me it will take about 2 and a half days.

So what will it cost to buy enough solar panels to fix my problem? About $400 to $1000 depending on what i buy. But now im looking at a solar panel system so big, im stuck car/truck camping. But if im stuck camping near a car,then why wouldnt i just run the car for an hour? Or buy a lunchbox sized honda generator. Honda sells a 1000watt generator, it has a 10 amp charger on a motor that is quieter than most cars.

Friends, do you get the impression that solar panels are extremely wimpy and useless? I do. The next time someone tells me that solar panels are the future, i plan to tell them to stop try to blow smoke up my arse.

Just saying.
 

JamesBondo

House Member
Mar 3, 2012
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I can not in good conscience recommend solar panels. Even when the system is working well, i would have to warn you to EXPECT problems.

I can accept problems when trying to recharge a cellphone or fm radio. But anything somewhat important like a medical device, don't waste your money.
 

Musky

Time Out
May 19, 2017
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I can not in good conscience recommend solar panels. Even when the system is working well, i would have to warn you to EXPECT problems.

I can accept problems when trying to recharge a cellphone or fm radio. But anything somewhat important like a medical device, don't waste your money.

Think small all you want.

It's coming and fast.

Hide under your bed.
 

IdRatherBeSkiing

Satelitte Radio Addict
May 28, 2007
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Toronto, ON
Obviously you did not pay enough tax on the panel for it to function properly.

I would suggest either pay more tax or move to California for better results.
 

Angstrom

Hall of Fame Member
May 8, 2011
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Solar panels may be a good solution for countries near the equator. But thats not Canada
 

JamesBondo

House Member
Mar 3, 2012
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on the bright side, I've got a 200mA charger that will charge my cellphone and all my buddy's cellphones while we are out camping.

but even that seems like a poor way to spend $100, because once I have a RV battery with a 180 Amp hour capacity(to solve my cpap problem), I can charge everyone's cellphones without the problematic unreliable 12in by 20in solar panel.
 

Danbones

Hall of Fame Member
Sep 23, 2015
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Again I don't get why people hate renewables.
its the political lack of math, science, and common sense that goes with them.

@ JB
btw: you can pick up not bad scrap batteries at the chandlry and rejuvenate them with Epsom salts and distilled water - on many of them it will work, and on the ones that it doesn't - back to the scrap pile.
Many batteries wind up there from seasonal refits, and so are still salvageable.