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Regenerating LICs - manufacurer's opinion (do not)

JWx

Hello!

For clarity I have asked manufacturer's support if there is something than end user can do to restore hybrid capacitors that have arrived short-curcuited and they stated that "altrough there may be methods to regenerate them, it is typically not advisable to do it for commercial or safety reasons" and risk of failure or reduced performance can be high and it is usually safer and more reliable to replace them.

So I understand that the case is not hopeless but the manufacturer is not advising it for serious use cases

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  • It's a bit disappointing that manufacturers have not created a convention of (say) different-colored sleeving on these capacitors, so that when it comes to repairing boards, people don't accidentally discharge them.

    They look almost exactly like normal capacitors : (

    Older supercaps seemed to be following a convention of white colored sleeving (at least, all the ones I purchased a few years ago, from (I believe) two different manufacturers) were colored white, which is a more unusual color for a normal capacitor.

    Hopefully PCB designers start making it clear on the board which parts are supercapacitors, perhaps with silkscreen, or even a bit of tape over any through-hole pads to prevent it accidentally touching metal for any extended periods, if the potential leakage of the tape and moisture/dirt on it is acceptable in the design.

  • in reply to shabaz

    Remember that "supercapacitor" was originally the tradename for the first "electrical double-layer capacitors."

    The idea of putting lithium on one of the electrodes created "hybrid supercapacitors."

    So, while I agree such hybrids should have a pseudo-standard (or standard) for identifying them... let's not lump all "supercapacitors" into the same labeling requirements.

    Related, what is the "standard" for the positive and negative indicators on a battery's quick-connect terminal?

  • in reply to baldengineer

    I'm not sure on battery indications (a lot of cheap "generic" lipo cells come with the red and black wires connected in opposite direction in the connector, to other generic lipo cells: ( All a bit of a mess.

    Probably the low internal resistance parts with high capacity need special attention too, since even if they might be physically OK, an accidental shorting would probably make someone fall off a chair or ladder (i.e. from the surprise, not electric shock). But maybe that's a job for the end equipment manufacturer, to call it out or to have the underside of the board inaccessible without further disassembly (e.g. an insulated sheet attached to underside).

    At the PCB level orgs will have their own internal standards, e.g. all  super-important info should be in copper layer, so certainly these particular supercaps ought to have their anode or cathode labeled as such on boards (i.e. things like the standard KiCad footprints for capacitors would not do), especially for the through-hole parts, since some factories would assemble those parts by human. 

    It would be neat to see or design some "good practice" footprints for these parts, I don't know if anyone has these or is planning to do that, with very clear polarity indication in copper with no mask for instance, and some other information to make it clear it must not be shorted. Not a fully-baked solution, but just to throw out some ideas, maybe some hatching on the solder side of the board, with "DO NOT SHORT" - I don't know of a universal symbol for that! : ) 

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  • in reply to baldengineer

    I'm not sure on battery indications (a lot of cheap "generic" lipo cells come with the red and black wires connected in opposite direction in the connector, to other generic lipo cells: ( All a bit of a mess.

    Probably the low internal resistance parts with high capacity need special attention too, since even if they might be physically OK, an accidental shorting would probably make someone fall off a chair or ladder (i.e. from the surprise, not electric shock). But maybe that's a job for the end equipment manufacturer, to call it out or to have the underside of the board inaccessible without further disassembly (e.g. an insulated sheet attached to underside).

    At the PCB level orgs will have their own internal standards, e.g. all  super-important info should be in copper layer, so certainly these particular supercaps ought to have their anode or cathode labeled as such on boards (i.e. things like the standard KiCad footprints for capacitors would not do), especially for the through-hole parts, since some factories would assemble those parts by human. 

    It would be neat to see or design some "good practice" footprints for these parts, I don't know if anyone has these or is planning to do that, with very clear polarity indication in copper with no mask for instance, and some other information to make it clear it must not be shorted. Not a fully-baked solution, but just to throw out some ideas, maybe some hatching on the solder side of the board, with "DO NOT SHORT" - I don't know of a universal symbol for that! : ) 

Children
  • in reply to shabaz

    Google was super-helpful!

    image

    Perhaps this could work..

    image

  • in reply to shabaz
    This reply was deleted.
  • in reply to shabaz

    Pump the brakes... No Johnny 5?!  I am NOT on board.
    How do I miss these?

  • in reply to kmikemoo

    Same here, I do not want to imagine a world without that movie! : )

  • in reply to shabaz

    Have you seen the lockdown replica ?

    Johnny 5 On the BBC! - Full Interview.