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I am working on a project where I am trying to use a mobile battery power bank as a supply to my system. The battery power bank can provide 5 V @ 2.4 A. The output of this power bank goes into 2.1 mm DC Jack installed on my platform. At the input of my platform, I have a boost converter to transform 5 V (from battery power bank) to 6 V which is used by other circuits in my system.

I see that the input 5 V gets discharged in a periodic manner approximately with 2 s period which causes the output of my boost converter to also vary periodically and reset the other circuits. I have verified that this behaviour occurs even when the boost converter is not loaded and not connected to any other circuits.

However, everything works correctly if I supply my system with a bench top power supply instead of a power bank.

So coming to question, do you guys know what might be really happening here with power bank supply?

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    \$\begingroup\$ I think you've adequately described what is happening so post a schematic and expect answers as to the cause, to follow thereafter. \$\endgroup\$
    – Andy aka
    Commented Oct 22, 2018 at 11:59
  • \$\begingroup\$ What kind of power bank are you using? Some are way crappier than others. Have you tried a different one? \$\endgroup\$
    – Passerby
    Commented Oct 22, 2018 at 14:39
  • \$\begingroup\$ Hello Passerby, I am using a power bank from RavPower - ravpower.com/… Thanks \$\endgroup\$
    – Nik
    Commented Oct 22, 2018 at 14:58

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I figured out the problem. I am just sharing here if someone encounters similar problems in future.

I tested my platform using a power bank, however, my complete system was in power down mode except the power boost converter and LDO (so mainly power supplies were ON). This usually consumes very less current because the quiscent current of power supplies is very less in no load case. This microAmperes of current through this power supplies is in turn supplied by power bank which makes power bank think that its charge is getting leaked. So power banks have a minimum discharge current, which if detected will trigger a shutdown of power banks after a certain time (usually 30s).

Now if I make sure that my other circuits in the platform are powered up then my whole system works perfectly with the power banks without any shutdown.

Thanks Nik

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  • \$\begingroup\$ Thanks for adding your own answer. I realise that English probably isn't your first language, unfortunately I just can't understand some points :-( For example: "complete system was in power down mode" OK, so this suggests your system's own power supplies were OFF - but then you say "so mainly power supplies were ON". What?! Now I (and other readers) are confused :-( "makes power bank think that its charge is getting leaked" FYI that's not the process. Instead it is, as you later say, that many (though not all) power banks switch off the output unless X mA is consumed for Y seconds. \$\endgroup\$
    – SamGibson ♦
    Commented Oct 23, 2018 at 22:05
  • \$\begingroup\$ [continued] Can you please edit the answer to clarify your points? Adding a diagram showing the other parts of your system, so you can refer to power supply PS1 or LDO U3 etc. will help readers to understand what you are saying. When we understand enough, someone will be happy to tidy-up any awkward grammar (no-one expects perfection!). Thanks. ... If you've got any questions, please leave a comment here prefixed by "@" and my username and I'll try to respond. (Such comments are usually deleted later to tidy-up any obsolete points.) \$\endgroup\$
    – SamGibson ♦
    Commented Oct 23, 2018 at 22:12

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