x in range function for float in python
<p>I want to test whether a voltage is within the allowed range:</p>

<pre><code>SET_VOLTAGE = 13
ERROR_VOLTAGE = 0.5
Vbatt = 12.86
if Vbatt in range ((SET_VOLTAGE-ERROR_VOLTAGE),(SET_VOLTAGE+1+ERROR_VOLTAGE)):
    print'True - Value in range'
else:
     print'False - Value out of range'
</code></pre>

<p>This code always prints the <code>False</code> value.  Why?  And what should I do to fix it?</p>