Our devices, becoming more and more incorporated in our everyday lives in addition to our bike rides, require power. Be prepared when the low battery lights starts flashing. Keep your music systems playing, our fitness and cycling computers, pedometers, and power meters recording important information, and your headlight and taillight illuminating your way. Watch batteries, AA, AAA, C, lithium, alkaline, 9 volt, rechargeable batteries, and portable power sources available.