How to Get Started with LED

Connect a LED with a battery and a resistor. The long leg of an LED is the positive, the anode. You could connect a LED directly to a battery without a resistor, but that probably wouldn’t last very long. The resistor acts as a load and limits the amount of current in the circuit. When just starting out, you don’t need to worry about the technical details, just know that it’s best to add in a resistor when wiring a LED. For my example, I’ve chosen a ~5VDC power source (3x AA batteries, 4x AA batteries would have worked just as well) and a 220Ω resistor. Resistor voltage and power ratings aren’t important for this example, any ~200Ωish resistor will do. I like the battery holders with a builtin power switch. The type of LED shown here are 5mm through-hole (THT). Should be pretty common in electronics/hobby shops. They might even have these at RadioShack/The Source.

Connect One LED

This is how I would connect a single LED to something. The white plastic rectangle is a full-sized breadboard. It allows quick electrical connections without the need to solder or mess with alligator clips or electrical tape. Great for testing and experiments. Using just regular AA batteries and simple components, don’t be afraid to just connect things and see what they do. You won’t do too much damage. Maybe just don’t short the positive and negative of the battery together and continue to hold it in your hand. If you do want to short a battery, do so and toss it away from yourself.

  • POSITIVE of battery goes to POSITIVE of LED
  • NEGATIVE of LED to one end of resistor
  • Other end of resistor to NEGATIVE of battery

Connect Multiple LEDs

Connect Multiple LEDs in Series

I think most common strings of battery powered LED Christmas lights are wired this way with multiple LEDs connected in series with a single resistor. You may need to increase voltage or lower resistance depending on how many LEDs you’re connecting together. If one LED burns out, none of the other ones will light up.

  • POSITIVE of battery goes to POSITIVE of Green LED
  • NEGATIVE of Green LED to POSITIVE of Red LED
  • NEGATIVE of Red LED to one end of resistor
  • Other end of resistor to NEGATIVE of battery
Connect Multiple LEDs in Parallel with Separate Power Connections


This is the most robust way to wire multiple LEDs together. Individual burnt LED or resistor won’t affect the lighting of the others. Also make note of the brightness of the two LEDs compared to the previous connection where they were connected in series. If space and budget allows, this is what I would do for my projects where appropriate.

  • POSITIVE of battery goes to POSITIVE of Green LED
  • NEGATIVE of Green LED to one end of resistor #1
  • Other end of resistor #1 to NEGATIVE of battery
  • POSITIVE of battery goes to POSITIVE of Red LED
  • NEGATIVE of Red LED to one end of resistor #2
  • Other end of resistor #2 to NEGATIVE of battery
Connect Multiple LEDs in Parallel with Shared Power Connection

  • POSITIVE of battery goes to POSITIVE of Green LED
  • NEGATIVE of Green LED to one end of resistor
  • Other end of resistor to NEGATIVE of battery
  • POSITIVE of battery goes to POSITIVE of Red LED
  • NEGATIVE of Red LED to one end of resistor
  • Other end of resistor to NEGATIVE of battery

This is a middle ground between redundant everything and space constraints. As you can see, there are multiple ways to achieve the same end result (lit LEDs in this case).

There are many more related topics that you can dive deeper into, but this should get you started with LEDs and electronics in general. Enjoy!

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