Is it possible to charge a battery using sound power from the microphone.?

Answer 1

You could, however it would most likely take a very long time to do so for a typical rechargeable battery such as an AAA sized battery. A microphone works like a speaker but in reverse. Sound waves travel through changes in air pressure which causes a cone to vibrate. Attached to the cone is a thin wire wrapped around the bottom. This coil is suspended around a magnet so the vibrations moving the coil causes this combination to act like a mini electric generator. Instead of amplifying these electrical impulses to produce sound or transferring them to tape or CD, you could capture them. You would need a diode to change it from AC to DC but this energy could be used. Since the amount of energy is so minute, it would take forever to charge a battery, but it could be done. Of course, the larger the microphone and the more sound energy to hit it, the more current you could get from it and the faster the battery would charge.