Hi! I am pretty new to circuitry (working on my first few projects). One of my projects was an LED flashlight hat. I had wired it up and everything, and it worked great. I used two 9v batteries in series with 5 LEDs in series, meaning each LED was recieving approx. 3.6v each. I have used the LEDs with 6v ea. using two 3v batteries wired in series, and it just made the LEDs really bright so I figured if I added another 9v battery meaning a total of 27v, that would be 5.4v per LED and it would just make it really bright. So I added it in and... It blew the LEDs. All five of them. Can anyone explain why, I do not understand why 5.4 blew the LEDs when 6v didn't.