How to clean output from a ubec
Use shielded twisted pair wire for serial data.

5 volts is not enough.

The WS2812 VDD and VCC power requirements are 6V-7V.  



All 3 LEDs drawing 20mA x 3 x 288 = 27.28 Amps.

That's the Amps.  The minimum Voltage is 6V x 27.28 = 103.68 Watts.

The LEDs alone could dissipate up to 50 Watts,  With an avaerage of 2.933 Vf (R=2.2v,G=3.2v,B=3.4v) x 3 x 288 = 50.688 Watts

But efficiency is less than 50%.  

6v x 0.02A x 3 x 288 = 103.69 Watts @ 6V = 17.28A

Give your UBEC an 80% efficiency and we have 129.6 Watts

Add a 10% margin and the battery requirement is now 142.56 Watts

You could use a electric bicycle battery. You will need an NMC Li-ion (high capacity and high current).  The LI-ion for my Segway is $1,400.



If you use the WS2812B with 5V VDD then you would need 86 Watts @ 14.4 Amp.

If you calculated the power requirements for the LEDs without taking efficiency into consideration the draw would be about 8 amp.  58% efficiency (not including UBEC).





You may want to consider using Cree RGB CLMVB-FKA controlled with a TI TLC5973 3-Channel, 12-Bit, PWM Constant-Current LED Driver with a single resistor to set the maximum current. Or a TLC59731 3-Channel, 8-Bit, PWM LED Driver which uses a resistor inline with each LED.



The Cree RGB have an average Vf of 3.6 vs 2.9 (less power) The Luminosity of the RG and B are better matched.  The TLC5973 can be powered with 3v up to 6v so it could be powered by a single cell 3.6v Li-ion eliminating the UBEC, Over all the power requirements would be much less and reliability much higher.  

Uses a single wire interface. The datasheet shows how to properly wire power and data signal.

There is an on-board shunt regulator that allows you to power multiple LEDs with one chip. 

  

The TI parts are superior to the NeoPixel. And MUCH better documentation.


Data Transfer Maximum Rate: 3 Mbps vs. 800Kbps
Internal GS Clock Oscillator: 12 MHz
Display Repeat Rate: 2,900 (typ) vs  30fps,
4096 steps grayscale control vs 256
Output Delay Switching to Prevent Inrush Current