nPower PEG Personal Energy Generator Battery Backup For iPhone iPod Droid Galaxy etc. The nPower PEG is the world's 1st human-powered charger for hand-held electronics. The PEG gives you access to backup battery power even when you're away from a wall outlet. It uses the energy you generate while walking, running, or biking to charge your smart phone, music player, GPS, and other devices. Rain or shine, day or night, you'll have backup battery power. The World's 1st Kinetic Energy Charger for Hand-Held Devices.