USB Powerbank > Arduino > 2.5A draw on WS2812B pixel strip

Do you foresee any issues with hooking up an Arduino Uno R3 to a Cygnett Power Bank?

The plan is to use the 5V output on the Arduino directly to the 2m pixel strip which I theorise will use maybe 2.5 amps max, but usually around 1.5. Are there any potential gotchas I should watch out for?

5V output on the Arduino?

That won't power the strip.

There is a 500mA polyfuse and a tiny mosfet between USB socket power and the 5volt pin of the Arduino.
Not wise to power the strip THROUGH the Arduino. Magic smoke could be released with 2.5Amp.

OK thanks. So how would I use the powerbank for both?

In ref to the power bank and if it can run the Arduino and the led strip, you wont know till you can actually run this unit as i have seen many claims on ratings that have failed.
One i have run across is that the unit is rated at 5000mA but this is on the 3.7 volt lithium that is then boosted to 5 volts. So at 5 volts the unit will only discharge say 3,700mA before it goes flat.

Running at 2500mA (its maximum) will put a strain on it. Best to run things a 50% to be safe, or allow for 100% redundancy.


OK thanks. So how would I use the powerbank for both?

I guess you have to fabricate or find some USB power splitter cable or hub.
Or use two power banks.
Or find a power bank with several UBS outputs.

You can just look up the wiring for a usb port, cut a usb cable and use the red and black (I think) for the posative and negative.

Have a look here.

This site has a mirad of connectors and over the years has been a great help.