Probably an extremely easy question but I was wondering how to wire a red led light running on a small battery with a switch. A general description and a list of needed mat. would be super helpful.
A red LED is about 1.8V. The lithium coin battery is 3.0V. For 12mA in the LED the current-limiting resistor is (3.0V - 1.8V)/12mA= 100 ohms. The datasheet for the battery shows it lasting a long time with much less current. It might provide 12mA for a few minutes.