The Soltronix headphone radio is a solar recharging AM/FM headphone radio with superb sound. The solar module allows it to operate on just solar power in as little as thirty percent of full sunlight. Additional power generated goes to charging the battery while the headphones are still operating! When the headphones are off, all power generated by the module goes to charging the included NiMH battery. One hour of charging in bright sunlight in a windowsill gives 1-2 hours of play time, and a fully charged battery provides over 18 hours of play time. The user benefits both from the savings and convenience of not having to change batteries.