There’s a product being advertised that is incredibly annoying.
Because I don’t want to use the name, we’ll just call it “Shit Mobile” or “Shit Solar”.
I can only assume that they’ve drank the Kool-Aid and have succumbed to — no, that perhaps they eagerly embraced it — their own junk-science and bullshit marketing. I’ve been absolutely bombarded with their ads constantly.
So it has my attention.
- 20,000mAH capacity.
- The product is a battery for recharging your USB-powered devices.
- On one side, it includes an integrated inductive charger — probably Qi* and an LED illumination array.
- On the other side, it has a solar panel that can “recharge the battery in about 60 minutes.”
- It appears to be about 7 cm x 15 cm and perhaps 2 cm thick.
And it’s being marketed as one of those mock “unboxing” videos.
An hour to charge it fully in sunlight, eh? I’d certainly like to test the claims, but I’m not going to order one. But we can certainly do some math.
Let’s start with how large is the PV panel on the device itself? We’ll be generous here, and use its outer dimensions, disregarding the bezel around the edge: 7 cm x 15 cm = 105 cm sq.
Next, a typical photovoltaic (PV) panel has an output of about 200W per square meter in direct sun. The theoretical collection is 1KW per square meter, but panels are only about 20% efficient. (20% of 1000W = 200W). Again, we’ll be generous and assume it’s the most-efficient solar panel possible under current technology.
So, that’s 1.05% of the 200W panel size (0.0105 x 200): 2.1W.
That’s the open circuit output.
And you want to fully charge a 20,000mah battery in an hour? What was its state of charge before you began your test?
At USD$110 (!), it’s simply not cost-effective. Not even if I find myself in need of replacement or addition to my USD$18 10,000mah Anker battery that I’ve had for about three years. There are far better and less expensive solar charging and power solutions available.
* Not quite everyone has caught on, but Qi is pronounced | CHē | (Chinese: 气). I’m only adding this brief rant to the rant because I’ve observed many people stumble and pronounce it | kē |, | kwē |, | kwī | and simply say the name of the letters as Q-I. Maybe products of American public education have a fear of the letter Q and the many uses it can have.