Hello I would like to create an Arduino protoype with Led WS2182B. I currently have Arduino NANO (not UNO, like in this schema) 65 Led WS2182B = Which gives me 3.9 Amp of suply for full brighness (65*60mAmp) Power supply of a movil charge wich have 5V 2.1 A

I am currently working with this schema from this website

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I have a few questions

  1. Does this battery will work for this schema replacing the usb conector?
  2. Can I use the 68 leds at a medium energy, to make it suitable wih the power supply? Can this damage any device (Because in theory I believe it needs more than 2.1 Amps) 3)If this battery will not be appropiate to this schema. What could I do?

Thank you very much!

  • 1. Are you using a battery or a wallwart power suppy? What exactly are you using? 2. When you already calculated that you need 4.68A and your supply gives you up to 2.1A, does this sound like it would fit?
    – chrisl
    Commented Jun 25, 2022 at 14:30
  • @chrisl hello Chris, I am using an portable battery for smarthphone. The amount of Ampers used is at the maximun capacity, my doubt is if I can use at a medium capacity or so
    – RodParedes
    Commented Jun 25, 2022 at 14:38
  • Do you mean a standard USB power bank? You can get max 2.1A/3.9A = 53,8% intensity. Though you should go considerably lower. With your current supply you should always plan with some headroom, like 50% more than you need (especially since power supplies of all kind can get rather inefficient near their maximum rating)
    – chrisl
    Commented Jun 25, 2022 at 15:35
  • @chrisl yes, indeed a USB power bank, thank you Chris, I think that I get the point, you reccomend me that I use those leds lets say into a 25% of the intensity so it will peak at the full capacity, right? Do you know what I can use to replace this power bank, or from an existing tutorial to work in this type of cases (a portable device which lighlty exceed the capacity of an USB power bank)?
    – RodParedes
    Commented Jun 25, 2022 at 17:05

1 Answer 1


You are using a standard USB power bank. It should be possible to power your project as long as you stay below the current limit (2.1A). Probably you should keep the intensity small enough to not exceed 1.9A in normal operation. That should be enough for about half intensity. You really don't want to exceed the current limit. And you should measure the actual current draw and then approach your own current limit (like 1.9A) from below. Calculations are good, but when operating like this you should look at the real values.

If you exceed the current limit of the power bank it depends on the implementation of the power bank what will happen. Most likely the power bank will cut the power but still work. Though it is also possible, that you fry some electronics inside the power bank and kill it this way.


  • While you experiment with your code you can use fewer LEDs, so that they would be able to light up at full intensity. That makes sure, that you don't damage anything from a small programming error. If you write your code in the correct way (for example defining the number of LEDs at exactly one code line and reusing that name everywhere), then it will be easy to increase the number of LEDs to the target and also be sure, that you are staying within your limits.
  • You already have it in your wiring diagram, but nonetheless I want to emphasize, that you must not power the LEDs through the Arduino. You need to connect them directly to the USB cable to the power bank. The Arduino cannot withstand such currents.
  • USB power banks often cut power, when not enough current is being drawn from them (and for mine the current of an Arduino Nano wasn't enough to hold it active). If in your project the LEDs get turned of at some time, while the Arduino should keep running, the power bank might cut the power, thus turning off the Arduino. In my experience the bigger, more expensive power banks will do that, while small, cheap ones will just keep outputting the power. If this scenario is relevant for you, you need to test this yourself with your specific power bank.

If this battery will not be appropiate to this schema. What could I do?

You could use multiple of these power banks, each of them powering its own part of the LED strip. One of them can also power the Arduino. Just make sure to connect all grounds together.

  • Thank you, Chris!
    – RodParedes
    Commented Jun 26, 2022 at 0:21

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