Portable NeoPixels

Hello all,

I am interested in using the item of: https://www.adafruit.com/product/2832 but I want to have it powered by a battery source. I am using an Arduino Uno for the controller. A friend of mine suggested a behemoth of a "Eveready 6 Volt Lantern Battery 1209" battery. I do not want my LEDs to run all day or anything, just about 4 to 5 hours. Is this battery size accurate? I was thinking more of along the lines of: "Battery Pack 16750 RAVPower 16750mAh Portable Charger Power Pack Power Bank + 2A Wall Charger (Dual USB Ports, 2A Input, 4.5A Output) Power Charger for iPhone, iPad, Galaxy S8/S8 Plus and More - Black"

How many neopixels will you be driving? Each pixel could draw a maximum of 60ma oops, 80ma.


Edit: do you really need the white?


Much will depend on how many LEDs and how bright. Max is 80 mA per LED. Multiply by the number of LEDs to et maximum current. Multiply average current by the number of hours to get mAh your battery needs to supply. Your battery is not going to produce a steady 5V so you will need a boost or buck converter to efficiently change voltage.

Let's say you want two meters of strip (60 LEDs). That's a max of 4.8 Amps (60 * 0.080A). Call it 5 Amps. Your battery and boost converter will need to be capable of supplying that current. If you average half power (2.5A) and want the strip to last 5 hours you need 12.5 Ah at 5V or 62.5 Watt-hours. Divide by the battery nominal voltage. For a single-cell LiPo pack (3.7V) you need about 17 Ah (62.5 Wh / 3.7V).

RGBW's actually reach 80mA per LED.

OP makes no mention of how many meters, so who knows what the reqs are.

No need for buck/boost with those USB powerpacks.

My strip is 30 LEDs. So, taking Johnwasser's formula I do 80 x 30. I get 2400. Based off of his example I get 2.4A.

So a 16750mAh USB power bank should have plenty of power to run the strip at full brightness for 5 hours.

Ok. So, by now I have figured out that just trying to directly use the power bank of: https://www.ravpower.com/16750mah-portable-charger-power-bank-black.html directly is just too easy to ask of Electricy/laws of physics. lol It was noted that a buck boost thingy might help on this project. Is that in the right direction? and what type am I looking for?

Not 4.5V... 4.5A: "Dual USB Output: 1 x 2.4A USB port + 1 x 2.1A USB port (total output of 4.5A)"

You should power the 30 LED strip from the 2.4A output and the Arduino from the 2.1A output.

Ok. It sounds like I can power my LED strip directly from the power bank. Let me see if I can find the connections to go from LED strip to USB power bank.

lonesoac0: Ok. It sounds like I can power my LED strip directly from the power bank. Let me see if I can find the connections to go from LED strip to USB power bank.

You make them. Take an old USB cord, chop it, use the wires. You will spend days trying to find something, weeks/months waiting for it to arrive, when it's a 3 minute job with a pee break.

love the response. Thank you.

Ok. So I actually managed to cut an old USB cord and use it for power. Right now I have my arduino and LEDs pulling power from my raspberry pi. Not sure if that is a good thing or not. Also, when I was powering my LEDs off of the wall outlet, I had a 1000uf 6.3v capacitor in the circuit. Now it seems to have been incidentally removed. Should I worry about that? I do not think so since the capacitor was there to protect the LEDs from "too much power". Now that I am pulling power from a raspberry pi I think that worry is somewhat mitigated. Then again, I have basically no training in this area. lol

Hi, Why are you using a Pi to power the project? Where on the Pi are you getting your 5V, what is the 5V connection of the Pi rated at? Look up the Pi specs.

The cap is not needed, its doesn't "protect the LEDs from "too much power"."

Tom.. :)

I just plugged in my newly created USB power plug into the Pi. It seemed to be powering the Arduino and LEDs just fine. Let me check out the power rating for the Raspberry Pi v3.

UPDATE: Ok. So I found the power specs for the Pi 3. I found:

Product: Raspberry Pi 3 Model B

Recommended PSU current capacity: 2.5A

Maximum total USB peripheral current draw: 1.2A

Typical bare-board active current consumption: 400mA