user3912: My wording might be a bit confusing, if I plug an 8 volt battery into Vin, will the arduino be powered and will the 5V pins work?

user368: 

VIN. The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.


source

user313: Yes, that's what the Vin pin is for: unregulated voltage or a voltage higher than 5V. Then the 5V pin will be at 5V, regulated by the on board regulator. You would only connect a source to the 5V pin if the source is already a regulated 5V.

3912: <p>My wording might be a bit confusing, if I plug an 8 volt battery into Vin, will the arduino be powered and will the 5V pins work?</p>
 368: <blockquote>
  <ul>
  <li><strong>VIN.</strong> The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.</li>
  </ul>
</blockquote>

<p><a href="http://arduino.cc/en/Main/arduinoBoardMega" rel="nofollow">source</a></p>
 313: <p>Yes, that's what the Vin pin is for: unregulated voltage or a voltage higher than 5V. Then the 5V pin will be at 5V, regulated by the on board regulator. You would only connect a source to the 5V pin if the source is already a regulated 5V.</p>
