Inside a common eBay fast-charge 5000mAh power bank.

A look inside a fairly common USB power bank sold on eBay. Note that I do not recommend that the output is loaded above 1A as demonstrated in the video, as 140C+ is way too high for semiconductor components!
Other than the slight undersizing of components for full 2A output, the unit is actually quite well made and fits a very large lithium cell into a rugged alloy case.

Jack Youngs pointed out that if the unit is using a buck converter during charging then the input mAh I measured is not going to reflect the cells mAh capacity, so it will actually be closer to 5Ah.

Here's a general search link for eBay.com.
http://www.ebay.com/sch/i.html?_from=...

If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm