Tearing Down a Cheap External USB Battery

[cpldcpu] recently received an external USB battery as a promotional gift and thought it would be a good idea to tear it down to see its insides. At first glance, he could see that the device included a USB micro-b socket used as a 5V input (for charging), a USB-A socket for 5V output, a blue LED to indicate active power out and a red one to indicate charging.

Opening the case revealed that most space was taken up by a 2600mAH ICR18650 Li-Ion battery, connected to a tiny PCB. A close inspection and a little googling allowed [cpldcpu] to identify the main components of the latter: a battery mangement IC, a 2A boost converter, a 3A Schottky diode, a few 2A N-Mosfets, a 300mA 2.5V LDO and an unknown 6-pin IC. It is very interesting to learn that every last one of these components seems to be sourced from China, which may explain why this USB battery is given for free. Do you think they designed it in-house and outsourced the manufacturing, or is this a product Digi-Key simply bought and put their name on?

Editorial Note: Digi-Key is an advertiser on Hackaday but this post is not part of that sponsorship. Hackaday does not post sponsored content.

Unrelated video of extremely similar hardware. [Thanks James from comments]


  1. polossatik says:
  2. JM says:

    LOL you think Digi-Key would actually design any of this stuff..

  3. Rob says:

    It is very similar to yubi Power YP250ABLK. Many of the usb batteries on the market share a similar design.

  4. fartface says:

    That one is not a cheap one, it is somewhat well built. I tore down a cheap one and found that there was NO battery management at all just a couple of zenier diodes and some passive components with a pic.

    Cheap china ones are built horribly unsafe, not using a charge controller on a LiPo turns it from a battery into an IED. It’s why I will not touch any of the low cost ebay or amazon china crap. I dont need my battery to explode on the airplane and spend the next 10 years in Gitmo because I was too cheap to pay for a real portable battery device.

  5. Dodo says:

    Wait, where did they install the Arduino?

  6. James says:

    Fairly similar

  7. ejonesss says:

    i am able to see the ebay item.

  8. butterfly says:

    “every last one of these components seems to be sourced from China”

    like every other fucking electronic component these days? WTF is this.

  9. Per Jensen says:

    [Julian Ilett] reviewed one of those: https://www.youtube.com/watch?v=XDCSDTV0yUo

  10. AMBAC client says:

    This is sold by some promotional gimmick firm that’ll print your logo on it. I received an identical one last week as a promotional gift with a big bold “Ambac” logo on it.

    • AMBAC client says:

      “JB-Topaz” is what the enclosed instructions say.
      It’s rated 2200mAH in the instruction vs 2600 in the article above. 1000mA 5V both input and output

  11. Isaac S. says:

    Unknown ic… Should plug it in and check what happens on the data lines.

    • Tony says:

      There’s are chips that will cycle through the various resistor combinations, could be one of those.

      Unfortunately they’re one of those “MOQ=10000″ things.

  12. Nicolas says:

    We got the same thing for free on the Embedded World 2014: https://www.youtube.com/watch?feature=player_detailpage&v=9JRBjsL0Trk#t=190

  13. SW says:

    Why does this site put contributors names in square brackets [like this] in articles? What is behind this affectation? Is there a reason for it?

  14. nes says:

    You can get these for about $1.50 on Aliexpress without the cell included. Just the extrusion, the pcb, the end caps, some tiny screws and a couple of square stickers to cover them. I picked up a handful to populate with cells from dead laptop batteries.

  15. David says:

    I took mine apart to find less parts. Bought from dx

  16. hulvi says:

    What happens if i connect these two usb ports to eachother with a micro usb cable

  17. David says:

    I took mine apart to find fewer parts. Bought from dx

    • cpldcpu says:

      Well, there are still five semiconductor devices. Did you decipher their markings? Unfortunately its tought to do from your pictures.

      • David says:

        Pics were all I could take. The components are mostly transistors and a diode, the unknown 17 component, a boost converter and schottky power rectifier. My unit does have three leds on it though. On (blue), fully charged (green) and being charged (red). I would guess the 17 component handles the leds.

  18. Rick says:

    I have this exact external battery but I had to buy it from Frys Electronics for $10 USd since I don’t get cool swag anymore. :( It’s branded “inLand” and “ProHT”. identical specs, button placement, light colors, etc.

  19. Thraxis says:
  20. NiN says:

    Batteries in those things are usually of poor quality, so declared 2500mAh is more like 1000-1500mAh. I’ve found better solution, case for two 18650s, with proper battery management electronics, and you choose the cells yourself. Funny thing, but Sanyo cells from “dead” laptop battery last in my case longer than new Chinese cells.
    URL : http://www.ebay.com/itm/360852001776 , you can probably find it cheaper than this. I tore it apart, found three chips, nine transistors and three diodes. Pretty decent. :)

  21. Flame Soulis says:

    I took apart a few USB batteries from China, and some are decent and others aren’t. I literately opened one up and found padding on the inside to fill up empty spaces in the case. I normally would state it was for shock protection, but the wadding was FAR bigger than it needed to be.

  22. OnlyGeek says:

    Hello, fellow nerds.
    I have close to none knowledge in electricity and things related.
    However, I am concerned about battery banks as I wish to use them. Well, as a matter of fact, I am concerned with a number of issues related to electronics.
    So I’d like to learn more about PCBs, voltage regulators, what are LDOs, charge controllers, IEDs, and so on.
    Can anyone recommend me some books (Amazon links are welcome) so I could start learning by myself?

  23. acidrain says:

    On a somewhat related note, I’d really love to find a decent UBS battery pack with a built-in AC charger. Just flip out the AC plug and charge it anywhere. Anyone know of one?

  24. one says:

    I actually tore down quite a few of these devices, at least 6 different models. They were bought as DOA but they were actually quite well made. The problems were either cosmetic, USB plug torn off and in one instance the output capacitor was blown. I gave some away and using some for powering up embedded projects.

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