I'd like to power a bunch (30 pieces) of 3.2V / 20mA LEDs with a 1S LiPo battery with 2600mAh.
The LEDs use a total of 600mA - so the discharge rate of the battery is only ~0.2C.
First I thought about using a step-down converter, but they don't work with such a low voltage drop of only 0.3V (3.6V - 3.3V).
So I'd use a step-up/step-down converter to bring the 3.6 to 4.2V of the LiPo to 3.3V. Then I'd use a 10 Ω resistor (series resistor) for each LED to bring down the voltage to 3.1V (and protect the LED).
Does that make sense?
How would you use a 1S LiPo to power your LEDs?