Hello there!
I've got a project where I am controlling some of the Lilypad Micro LEDs with an Arduino Lilypad 328 Main Board. I'm powering the project with a Lilypad LiPower board and a 3.7V LiPo battery. When I purchased the LiPower board, I didn't realize that it converts the 3.7V LiPo source into a 5V source. I am now worried about burning out the Micro LEDs, as they do not have a resistor, and the datasheets read the forward voltage as between 2.0v and 3.3v, with a maximum of between 2.4v and 3.8v, depending on the color. I've noticed that the LEDs are noticeably brighter than on the previous project where I used a coin cell battery. The LEDs are connected to the Lilypad main board using 30awg wire wrapping wire, so my guess is there isn't a lot of resistance there, but I am new to hobby electronics.
All that said, should I be concerned about burning out the LEDs? The LEDs aren't powered on continously. The project is actually reading an analog value from a microphone and powering the LEDs based on the volume level (VU Meter), and so the LEDs power on and off multiple times a second. Thanks in advance for your feedback!
William