6V LiFePO4 battery pack for Arduino Nano running WS2801 LEDs?

Hi!

I'm looking for a way to power my Arduino Nano and a string of addressable LEDs using a small battery. I've used 12v packs running through a voltage regulator but I'm wondering if I can just use a 6v (technically 6.4v) battery pack instead? LiFePO4 has a native voltage per cell of 3.2v so one is too little and two is too much. How much is okay? I'm powering about 40 addressable WS2801 LEDs that also need 5v.

Thank you!

Use an LDO 5V regulator for the LEDs, 6.4V is probably just enough for Vin on the Nano (can't remember if the Nano
has a Vin? If not run it from the 5V regulator too. Check what the current demand is before selecting a regulator.

Power

The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.