This fake 5,000,000mAh power bank could have exploded at any moment

This "5,000,000mAh" power bank arrived not working. But it was still highly dangerous and could have burst into flames at any time.
Written by Adrian Kingsley-Hughes, Contributing Writer

A few weeks ago, after some prompting, I fired up the eBay website and went in search of power banks that made ridiculous capacity claims. I ordered a few, wanting to see how bad they were.

The 9,000,000mAh power bank was, well, somewhat predictably, a disappointment, coming in at a measly 10,000mAh, and being of poor build quality.

Today another one of the power banks I ordered arrived. This one claimed a more modest 5,000,000mAh.

Note: For comparison, here's how big a 38,400mAh is.

Turns out, it was dead on arrival. I thought it might be discharged, but it wasn't taking any charge when hooked up to a supply.

I had nothing to lose from opening it. After all, it might be another one that didn't contain any rechargeable batteries (yes, I've had one of those in the past).

And I'm glad I did because this power bank was a bomb waiting to go off.

Must read: I bought a 9,000,000mAh power bank from eBay, and I got what I deserved

So, what could be wrong?

Sparks, that's what.

I opened it with a metal spudger -- not the best tool to be digging around inside a device packed with batteries, and I don't recommend it -- but it was quick, and once open I immediately saw what was wrong.

A loose wire. A loose wire right near to metalwork.

A loose wire that sparked into life.

Defective '5,000,000mAh' power bank

Safety warning: Don't mess around with defecting electronic devices unless you know what you are doing. Rechargeable cells contain a lot of power, and can cause fires that are tricky to put out.

If that wire had made a connection with the metalwork that lasted more than a fraction of a second, something would have given way. Maybe the wire would have melted, or perhaps the solder joints would have melted.

But it could have caused a fire and could even have caused the batteries to overheat, potentially resulting in a fire.

I took the plastic wrap off one of the batteries to examine it, and it looks like it's a poorly made cell that is showing signs of leakage or corrosion on the top.

I reconnected the loose wire to the circuit board and the power bank started working, confirming that this was the problem and that the batteries held a charge.

The argument could be made that this is a defective product rather than a dangerous one, but a fire is a fire.

What's ironic is that this power bank was only a few pounds cheaper than something made by a reputable company. These cheap power banks with their vastly inflated capacity ratings are flooding sales websites, duping customers into thinking they are buying a quality product.

As is always the case with dangerous or defective products sold in the UK, I liaise with UK trading standards officers to get the offending products removed from sale.

How to test chargers and power banks to make sure they don't blow up your expensive smartphone

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