Although our portable devices are extremely handy for listening to music, unless you wear headphones the sound quality needs to be enhanced by an outside source. Also, the darn things run out of power at the most inconvenient times (the middle of an eight-hour flight, with someone else’s toddler sitting next to you, for example). The Zephyr line of Bluetooth, high-definition speakers from SPAR, double as mobile phone chargers, making them the first portable, speaker/speakerphone/charger combination according to the manufacturer. A competitor to the JAMBOX, the line comes in three models: The Zephyr  300 can fit into a pocket and offers 12 hours of playtime; the 500 model fits into a bag or purse and runs for 18 hours; and the 550, encased in aircraft-grade anodized aluminum, is the largest of the three and offers 28 hours of battery life. You can throw one in the backpack for a picnic or beach trip or get one for a teen in place of an expensive sound system. With 28 hours of battery life, it would have …