Better night Frisbee golf

Now we need an article on building a circuit to power 2 3.2v led from a 3.7v capacitor AND a circuit to charge the capacitor from 5v USB wall charger.  If a 3.7v 80mA capacitor will power the 2 led brightly for 3 hours what could be soldiered atop it in parallel to provide 8 hours of bright run time?

Why? They sell these illuminating fiber optic tunes online and we want ours to have a longer run time.