LED Micro Lights Project

I need to know the correct power needs to string 6 LED Micro Lights together in order to purchase the correct battery or power supply to run the 6 strings continuously for up to 8 hours.

Each string is powered by 3 - 1.5AA batteries, yet the circuit board cuts the output to the lights to 1.9 volts. Not sure of the watts or amps and not sure how to get there…