Originally Posted by TreeLove
Just use any regular LEDs (0.7 V drop) with your CR2025 (or any 3V lithium coin cell) batteries. Sure, the voltage is too high, but who cares? They won't burn out. You will just get a bit shorter battery life, which is still like, forever. And they will shine brightly! No need to be an electronics purist and worry about using a limiting resistor.
At first, the only ones I could find were 1.85v
But then I found some 2.3v (I can remember right now)
They were still under 3v and we were worried they would burn out.
but the guy at the place I bought them tested one on a machine in the back room and said they would work ok at 3v