Virtually Free Power! The 15W Solar Panel by Monoprice


[dropcap]T[/dropcap]he Monoprice 15285 solar panel is a great source of virtually “free” electricity with 2 USB ports for your power hungry devices. It weighs very little, can be folded to a quarter of its open size, and can be bought for under US$40.

If you live most of your life in a cubicle or as a cave dweller without windows, this will do nothing for you since you need some actual sun for this to work. But for everyone else, this can be a great addition to our arsenal especially if you have south facing windows or spend any amount of time outdoors where power plugs are scarce.


It looks almost like a tablet case at first glance, spanning the length of your arm from shoulder to tip when opened up. It’s four sectioned, with three of them being solar panels and the fourth being a pouch containing two USB plugs to charge your items.

Physical size:
– folded: 10.4″ x 6.5″ x 0.6″ (265mm x 165mm x 15mm)
– unfolded: 25″ x 10.4″ x 0.1″ (635mm x 265mm x 3mm)

It’s sturdy and padded on the outside and made of good quality fabric (feels like cordura material, like on the bottom of backpacks). There are small loops all around, presumably to hang this solar charger on something. Maybe even to your backpack while you take a walk.

I’d imagined solar panels to be somewhat heavy, but this one is surprisingly light and not a big space hogger, considering the kind of value it pumps out. The “bulkiest” bit has to be the dual USB ports the panels are connected to, but other than that, it doesn’t take up much space. Like I said, it looks almost like a tablet case and in fact, weighs less than one at only 15.2 oz (430g).


Surprisingly brilliant! I was shocked to see the charging LED’s light up even though the panels weren’t facing the sun – in fact, it was facing away from the sun, and sitting in its own shade. I was going to simulate clouds by holding a large board over the panels, but doing so proved to be a useless exercise. The only way I was able to stop charging was to put the panels face down, and this was to see if the panels would re-engage/restart the charge without having to disconnect the cables. It did so every time, which meant I could walk away when it was charging without having to worry about babysitting.

But for best practice, Monoprice recommends charging powerbanks rather than phones as “some mobile devices will not draw enough constant power if the panel is not collecting enough direct sunlight.” I personally haven’t had any issues when charging my smartphone – it charged an average of 1% of a 1785 mAH battery every two minutes in the winter sun in New York (which means the sun was very low and not particularly strong.)


On the sleeve, we’re offered only two bits of technical information printed inside the sleeve.

15W, 5V

Um… what does this mean? Is it powerful enough to charge my car battery? Or will it gasp and sputter trying to fill up the cheapie street-vendor powerbank? Normally, this is where the physics lecture would start in figuring out amperage (which is the number you really want), but Monoprice has saved you from this chore by posting it on their product site – 2.1 amps.

Since USB chargers run on 5 volts, the number of amps determine a faster or slower charge (practically speaking). Cellphone chargers are usually 1 amp. Buy a cheap replacement and chances are, it’s giving you half that (.5 amps or 500 milliamps), which takes FOREVER to charge. With tablets, chargers are between 2 to 2.4 amps. Powerbanks vary, some take 1 amp and some take 2 amps (you have to read the fine print for the amount of INPUT amperage.)

This means you can charge two phones (1 amp + 1 amp = 2 amps) or one tablet (2 amps) at a time for the quickest charge in ideal conditions. You can of course plug in a tablet and a phone, but that could result in a very slow charge for both or perhaps even no charge at all.


It performs great, get one, by all means! I didn’t know how advanced solar panels had progressed, but seeing this one in action at such a reasonable price blew my mind. In addition to being a “free” source of electricity and being infinitely useful in emergency situations, this energy producing gem collects power even when it’s NOT placed in direct sunlight. Now that’s something to get excited about!

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Young is a Jack-of-many-trades. He's lived/worked on several continents for all sorts of companies (and has had his own too.) He meditates with origami and likes coffee, though he really should lay off that stuff.

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