I was given two sets of Reelights for Christmas. These are small lights that attach to the axle and have an electric charge induced in them by spoke-mounted magnets as the wheel turns. The model I have includes a capacitor in the circuit which (1) keeps the lights blinking at a steady rate independent of wheel speed, and (2) keeps them blinking for up to 3-4 minutes after stopping.
I installed one set on my winter commuting bike and have been using them for about 4 months. They worked great at first. The front one would stay blinking at least 5 minutes after stopping, longer than even the company's website promised. Now, however, I am beginning to notice a decreased duration of blinking after stopping. The front no longer keeps blinking even 30 seconds after stopping, even after my 5-mile commute which used to charge it enough to keep it going for 5 minutes.
Is it possible the capacitor has "burned out" or something like that? It still blinks at a steady rate when I'm riding, but it seems to no longer have any useful life after stopping.