Bargain bin, flea market trash power banks: are they any good?
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Bargain bin, flea market trash power banks: are they any good?

Aurel Stevens
Zurich, on 09.05.2019
Translation: Patrik Stainbrook
I bought a power bank on a street market in Italy. It’s supposed to carry 22,800 mAh. Unbelievable, judging from its size. Let’s take a look behind the veil.

Some time ago, a family holiday whisked me off to Italy. On a free day, we headed down to the local street market. In my opinion, Italian street markets aren’t what they used to be. They’re nothing compared to French flea markets, with their old Playmobil sets and dusty antiquities at every corner. Stall by stall, cheaper than the last, simple crap straight from the Far East.

A gauntlet for my wife. This is due our daughter – and me. Our little one is always magically attracted by blinking plastic stuff, no matter how trashy it is, no matter if it’s nearly falling apart on its own. For me, it’s a paradise for buying cheap electronics. I especially like getting dirt-cheap headphones, power banks and other items such as those.

My better half always rolls her eyes at this, but of course I know what I’m doing. Collecting inspiration for articles such as this one. Here’s one such candidate: a power bank. It fits perfectly well into any hand. «Probably around 2000 mAh,» I thought. Far from it: this little box of tricks is supposed to carry a mind-boggling 22,800 mAh. At least, that’s what it says on the back of the case.

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I know, that’s impossible. Only my largest, notebook-sized power banks carry 20,000 mAh, weighing around 400 grams. Cramming 22,800 mAh into something this small and light would be a Nobel Prize-worthy achievement in energy density. I probably won’t find this in a flea market for 12 Euros.

2018 is bound to be the year of the *revolutionary battery**
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What’s it really hiding?

The power bank is empty. I charge it and stick a USB-power gauge to it. USB-power gauges are a double-edged sword. Measurement devices such as this one prevent many a device from achieving its maximal possible output more often than not. Especially power supply-cable gadget combinations with quick charging enabled get slowed down.

Something they do very well, however, is measure energy flow. And that’s exactly what I want to do in this case. If not 22,800 mAh, then how much power do the power bank’s cells really store? This took a while to find out. The power bank’s charging technology is so bad that it got charged with 0.09 Ampere at 5.14 V. You read that right. Not 0.9, 0.09 Ampere. At this rate, it would take multiple days to completely charge it to its «maximum capacity» of 22,800 mAh.

Time for an autopsy

I didn’t have time for this. Someone get me a screwdriver. The case doesn’t actually have screws, but the tool helped me pry the plastic cage apart.

Warning: Don’t try this at home! Damaging the case can rupture the Lithium-Ion cells. They catch fire easily and burn to high heaven.

Jep: Some random electronics and two 18650 cells. These cells are 6.5 cm long and have a diameter of 18 millimetres. In consumer products with exchangeable power stores, this type of battery is rare. However, in power banks, torches and notebook batteries – devices that are hard to open –, 18650-cells are the industry standard. Tesla batteries contain a few thousand of these cells. Depending on make and use, they carry between 0.8 to 3.5 Ampere per hour (Ah) at 3.7 Volt.

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In our power bank there are two of these connected in parallel. In truth, this power bank doesn’t contain 22,800 mAh, but 2280 mAh. On a good day. With some luck. Once in a blue moon. I can’t tell you the exact numbers. I absolutely won’t open these no-name cells. I’m into risk, not suicide.

Verdict

You don’t really need a verdict. My power bank’s capacity data is a bold-faced lie. Even if I give them the benefit of the doubt and assume they accidentally added one too many zeroes – its horrible charging speed is more than enough to disqualify it from daily use. A trashy product that should never have left the factory.

What’s more: lithium-ion batteries are sensitive and dangerous. Too low a charge and they break, too high and they can explode. I don’t trust the technology in charge of checking the power level in the cells due to its disastrous performance.

The CE symbol – enough to pass EU regulations – must stand for «Chinese Export» in this case.

In short: 1. If something’s too good to be true, it’s not true. 2. Stay away from street markets if you’re looking for anything serious.

Already have some experience with fake products? Send me some pictures of the guilty product and its accompanying story – if I get enough, I’ll create a compilation with the scariest examples.

Something to end on: This article is also about a garbage product – I’m actually currently working on a story about USB charging cables: why do different cables charge my smartphone at different speeds? Follow my author’s profile, and you’ll get a mail when it’s ready.

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Aurel Stevens
Aurel Stevens
Chief Editor, Zurich
I'm the master tamer at the flea circus that is the editorial team, a nine-to-five writer and 24/7 dad. Technology, computers and hi-fi make me tick. On top of that, I’m a rain-or-shine cyclist and generally in a good mood.

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