Mini Pro 3,3 V FTDI + Liion Connected

Hi Gals, Hi Guys.

Hope ur all fine!

I have a smaller question on my ciruit. I am running a Mini Pro 3,3 V mostly over FTDI to get Serial output.

While getting print out on serial, I want to drive some WS2812B leds. My Battery provides 3,3-4,2V .

Normally, when programming, I unplug my battery from RAW-in of the Arduino Mini Pro. Is it possible to keep both conneted? Battery & FTDI on USB...

So... can I power my Mini Pro by FTDI / USB / 5V and only to drive the LEDs via Battery - connecting both. I mean I can connect the negative Battery pole to ground = USB ground.

Or may I power my Arduino by VCC in (regulated 3,3V) and my Lipo as it seems to be cabpable of 5V as well?

What would u suggest. How should I power my sensors & arduino (all 3,3V) and how to drive my few LED?

Thanks a lot.

P.S: It is fine when I use the VCC (out /in?) at the arduino to run my LED and sensors. But I can't say if i might draw to much when adding more LED...