Solar @ crappy tire (1 Viewer)

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Thinking about a pair of these @ $99 ea to help keep my fridge & LED lights' batteries charged. Have a generator but hate the noise.

40W solar panels

For the price, even though they aren't the best efficiency, it would be like buying a $300 '82 hyundai for your big family instead of a cruiser, it still works but there are better vehicles out there that cost more.

Convince me why this is a bad idea (or even worse analogy)?
 
well, assuming that the nominal wattage stated is correct (not obvious?), the efficiency doesn't matter, you'll get the 40W (under optimal insolation, orientation etc). Where the efficiency makes a difference will be in the size of the panel for a given max power. So low efficiency means a bigger panel to carry around. Of course, quality might also be reflected in the probability of poor connections, shorter life expectancy etc, but that is hard to quantify.

(other recent thread on this in this section)
 
The electrical math if I can use that term, seems straight forward. But it's hard to beat for $99.
 
40W is marginal to keep up with a fridge over a period of days. I'd suggest 80W minimum based on my experience.

40W is with full sun at a reasonable latitude, you may get less where you are located.

At the price you could purchase two panels.

cheers,
george.
 
Actually I would buy 2
 
Ah, didn't spot you wrote pair.

80W is good - especially if you are up north where you really don't get hot days. 80W with sunny days, even in northern latitudes (in summer etc) will easily keep up with a fridge etc.

cheers,
george.
 
Actually I would buy 2


Last I looked my 100W Renogy panel was $169 on amazon and so is cheaper plus it has more power.

However I've found that a good charge controller is important for getting the batteries a full charge. The cheapy one that came as a kit with the panel wasn't getting them up near 100%.
I wound up getting a BatteryMinder SCC-180 for $79 and it works beautifully.

BTW... It's 7:39 PM and my panel is still making juice. (Over 13V)
 
Last edited:
The thread/prices are from Feb 2013... Solar has become cheaper since that time... And the cost was at CANADIAN tyre - in presumably CAD$...

cheers,
george.
 

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