USB powerbanks without "trickle" switchingLooking for Device (self.UsbCHardware)

15 points16 points submitted by Mguerani

Hi,

I'm looking for small sized USB powerbank that will not switch off automatically when it senses that the connected device is fully charged. I don't know if there's a technical term to identify them.

Something in the 3000 mAh to 8000 mAh would be great.

Thanks in advance.

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[–]Eisenstein 11 points12 points  (6 children)

I have built a USB cable with an in-line resistor to trick a powerbank to stay on. If you feel like making one yourself I could tell you how.

[–]Mguerani[S] 1 point2 points  (4 children)

I can solder, so I could give it a try!

[–]Eisenstein 5 points6 points  (3 children)

Well, you have a few options:

  1. In-line resistor on a USB cable that always draws a bit of power when it is plugged in to anything
  2. Resistor in the helmet circuit that will always drawn a bit of power when it is plugged in with any USB cable
  3. #1 or #2 with a toggle switch to turn the resistor on or off
  4. A more complicated circuit using an IC that will pulse a load on the powerbank for a fraction of a second every so often

Which one do you want to do?

Do you have access to:

  1. A set of 1/4w or 1/2w resistors
  2. Miniature toggle switch
  3. Heatshrink, thermoplastic, rubber splicing tape, etc
  4. Multimeter
  5. Soldering iron and solder

[–]Mguerani[S] 0 points1 point  (2 children)

I'd rather go with option 2. Do I need the toggle switch?

A set of 1/4w or 1/2w resistors - need to order

Miniature toggle switch - got it from a differente project

Heatshrink, thermoplastic, rubber splicing tape, etc - got it

Multimeter - got it

Soldering iron and solder - got it

[–]Eisenstein 1 point2 points  (1 child)

You don't need the toggle switch.

You need to find out how much power you need to draw from your power bank in order to keep it on. I figure you have a USB connector since you are using one in the helmet so you probably bought a pack of them.

Rig up some wires to a breadboard or alligator clips on the power lines of a usb connector and clip a 250ohm resistor to it and see if it turns off, if it doesn't, double it and try that. If it does, half it and try that. You want to find the highest resistor that keeps it turned on. If you go 100ohms or below you need 1/2w resistors (ohms law, I = V/R, I = 5/100,I = 0.1A, P = I * V, P = 5 * 0.1, P = 0.5w).

Once you find the resistor needed, solder it between your power and ground lines on the circuit.

[–]Mguerani[S] 0 points1 point  (0 children)

OK, I'll try that, thanks!

[–]Star_king12 0 points1 point  (0 children)

Yeah I was thinking the same

[–][deleted]  (2 children)

[deleted]

    [–]SirDarknessTheFirst 5 points6 points  (1 child)

    My 13Ah PowerCore does not have this feature.

    [–]8GcB5U 4 points5 points  (3 children)

    Perhaps you could describe what you're going to use it for so we can understand better what you're looking for?

    [–]Mguerani[S] 6 points7 points  (2 children)

    You are right, I should have been more specific:

    I have cosplay helmet with 3 fans (5 voltes) inside, powered by an USB powerbank. After roughly 30 seconds, everything will switch off. If I press the power button, it will start again. The problem is that I can't press that button while wearing the helmet.

    [–]8GcB5U 10 points11 points  (0 children)

    Hmm. That sounds more like the fans aren't drawing that much current so the power bank thinks nothing's connected to it, but that might not be it given, you know, they're fans. What's their amp ratings?

    I can't say for sure though without knowing what those fans are and power bank though.

    [–]krumble1 1 point2 points  (0 children)

    With many power banks, you can double click or long press the power button to force it into a low-power mode like that. Are you sure yours doesn’t have an option like that? What power bank do you have?

    [–]SoapyMacNCheese 2 points3 points  (0 children)

    I know some Anker and Xiaomi/ZMI power banks offer this feature. You double or triple tap the button to trigger it. Also a lot of the cheap "dumb" power banks (the kind you might see sitting at a convenience store checkout or dollar store) leave the output on.

    You can also look at threads about the TS-80 USB-C soldering iron to find power bank recommendations. That device runs into the same issue, as once the iron reaches temp it draws almost no power, causing power banks to cut off.

    [–]JonathanSCE 2 points3 points  (0 children)

    Anker calls it trickle charge mode, Zendure calls it X-Charge mode. Both of these modes disable the auto shut off of the power bank when it assumes nothing is drawing power.

    The reason it's not on by default is when the power bank is sending power to the ports, even with nothing plugged in, the battery will lose its charge faster than if it was off.

    [–]goretsky 1 point2 points  (0 children)

    Hello,

    I don't have a specific brand or model in mind, but have looked into USB powerbanks that offer low amperage mode charging for Bluetooth headsets or smart watches? That might work for the type of use you are looking for.

    Alternatively, maybe building a 5VDC battery pack, and use rechargeable batteries with that?

    Regards,

    Aryeh Goretsky

    [–]ErzengelG 0 points1 point  (1 child)

    What device do you want to power with it? Some devices block trickle charging to protect their battery.

    [–]Mguerani[S] 1 point2 points  (0 children)

    I have cosplay helmet with 3 fans (5 voltes) inside, powered by an USB powerbank. After roughly 30 seconds, everything will switch off. If I press the power button, it will start again. The problem is that I can't press that button while wearing the helmet.