Which battery is best for making a 20 white LED flash light for longer duration? 6V-4.7Ah or 12V-4Ah?

I want to make a flash light using 20 white LEDs, I have one 6v-4.7Ah lead acid battery and one 12v-4Ah lead acid battery. Which battery is better to use for longer duration?Thank you, Wir.?

seandogue8 years ago
the equivalent energy is much higher for the 12V pack. Approximately 30% higher in fact. However, it in part depends on how deeply each can be drained, and on the conversion efficiency.