Home › Evil Mad Scientist Forums › Ask an Evil Mad Scientist › LEDs – Expanding Batteries – CR2032 to 2 C or D size › Re: LEDs – Expanding Batteries – CR2032 to 2 C or D size
March 28, 2014 at 2:47 pm
#21805
Windell Oskay
Keymaster
You do need to use the V= I * R formula, in almost all cases. The exception– the only case where you do not –is when the forward voltage of the LED is greater than the voltage source you are providing (for example, a blue or white LED driven from 3 V).
Also, an LR44 is a 1.5 V alkaline cell. Three C cells can replace three LR44s.