If you hang out on certain kinds of sites, you can find huge-capacity USB drives and high-power yet tiny solar panels, all at shockingly low prices. Of course, the USB drives just think they are huge, and the solar panels don’t deliver the kind of power they claim. That seems to be the case with [Big Clive’s] latest folding solar panel purchase. The nice thing about the Internet is you can satisfy your urge to tear things open to see what’s inside of them vicariously instead of having to buy a lot of junk yourself. Thanks [Clive]!
The picture on the website didn’t match the actual product, which was the first sign, of course. The panel’s output in full sun was around 2.5 watts instead of the claimed 10 watts. He’s also seen sellers claim they are between 20 and 80-watt panels. But the interesting bits are when [Clive] decides to rip the panel into pieces and analyze the controller board.
The tiny circuit board uses a buck regulator chip to feed 5V to the attached USB port. There are hardly any other components: a Schottky diode, an inductor, two capacitors, an LED, and the LED’s resistor.
Maybe those little panels would work for a Game Boy. We’ve seen some simple buck regulators before, but this one may be the most minimal.
I’m always amused by camping equipment that has a camouflage motif. It’s a recipe for it to be lost and have to buy another.
This seems like a poorly worded sentence. I’m not being pedantic. I got no information from what you wrote.
What?
You appear to have read things on Facebook that neither you nor the poster understood.
Ok, look, that’s not what Ohm’s Law says.
Ohm’s Law says that the voltage is equal to resistance times current. V=IR
Watts are voltage times current – VI – the presence of which would require that Ohm’s Law be in an invalid state. Specifically, the only way to get would be to convert the formula into something like V^2/R=VI, which is gibberish.
Don’t you read? Like Lincoln said, it’s in the Magna Carta.
Minimal would be opening it up, and finding a picture of a populated PCB.
Well there go my plans for a solar electric chair.
With a big enough battery, your dream could come true
Given a chair requires no electricity to be a chair, you should be sweet.
Ahh, yes. The infamous “eBay Watt”. If flashlight shopping, you will also encounter the “eBay Lumen”… The way some crooks inflate their item specs is just absurd! (999000000 lumen flashlights that run on one 18650… riiiight….)
Hrm…I wonder what an unreasonable engineer could get out of a Femto second laser using an 18650 cell…
Depends if that 18650 is measured in eBay mAh units or not….
^ this, these days there’s not a single LED, solar panel, battery, or power tool being sold that’s not making utterly ridiculous claims about performance, usually beyond the laws of physics never mind plain old sanity or credulity.
Honestly it sucks because I’ll happily buy your cheap product that doesn’t perform quite as well as the one that costs 5x the price, but when you advertise massive lies it’s impossible to know whether it will work at all.
And while we’re at it let me sell you (for an enormous price) an antenna the size of your pinkie nail whose bandwidth and gain violates any possible interpretation of the Chu-Harrington volumetric criterion, entirely based of course, on the priescent works of Nikola Tesla.
And to go with it, a sticker which will attenuate the harmful 5G frequencies to protect you.
He has a big problem. And he can’t normally take something apart without destroying it.
500mA at 5V is perfectly enough to charge any USB device. In fact, it is the typical capacity offered by these ports.
In 2008 maybe.
Even the cheapo dollar store USB chargers I find supply 5v @ 1-2W.
500mA at 5V is 2.5W.
I think he ment 1-2A.
They are 5-10 watts.
That’s another fun one they’re putting milliamp or milliwatt instead of just moving the decimal point makes it seem bigger than what it is right it’s a half amp then once it’s hooked up to a battery you get a fifth of an amp pendng on the charge state of the battery
Seems you know anything about how batteries charge either….
Who ties your shoes in the morning?
Look up the data sheet for NS6322, it is capable of 5V/2.4A
If you connect a variable load directly to the PV array, you can directly measure the V-I curve.
Or at least measure the open circuit voltage (which Clive estimated at 5.5V) and short circuit current (which Clive claims as 0.5A and the protect spec ’10W’ claims as 2.0A)
As an engineer, I always like to see real measurements, not hearsay claims.
Dennis,
That is simply not how solar panels work! The way that reputable companies rate solar panels is by measuring their maximum voltage (at zero amps) and then measuring maximum amperage (at essentially zero voltage). They multiply the two maximums to get max watts.
In real life you can’t run a solar panel in those conditions, but at normal full sunlight most panels get approximately 87% of the max rated wattage.
Your comments suggest to me that you tried to use a panel to either charge a battery that was almost full – in which case it cant provide its full power because of the battery’s limitations
OR
You tried to use a 12volt panel to run 5volt appliance, in which case you would get only a fraction of the panel’s rated power based on its I-V curve and has little to do with Ohm’s law, but the fact that solar panels are not voltage sources.
OR you tried to use a panel indoors thinking a flashlight was as bright as the sun and it is not even a fraction as bright 🌞.
The suns radiation is ~1000 watts/m3 and there are losses in the panels.
If anything is to small for generating 80 watts then its probably not 80 watts.
I recently bought pair of 150×130 mm 5V solar panels and a small, USB powered, motorized turntable from amazon. The turntable said it used 5V at 0.5A and required 0.25W – yes, it said both! The solar panels are claimed to be good for 500 mA each. I got lucky. A single solar panel powers the turntable just fine.
Now when the sun streams through my window, my mirrored mushroom spins and throws light beams everywhere like it’s 1978!
Now I need to figure out what to do with the other solar panel…
Pretty neat idea. You could sell those all day. Disco shroom!
The stall current of the motor may be 0.5 Amps, but when it’s running unloaded it’s quite likely to draw only 50 mA.
20w? 80w? I’m calling for 10,000w solar panel from Aliexpress and eBay by the end of this year to go with $20 256TB SSD and bazillion mAh 2032 sized rechargeable lithium batteries.
Who knew the libertarian ideal of market freedom and letting “the buyer beware” would be best realized by communist China
Wait that they upgrade to freedom units…