# Arduino Voltage Divider Connection

Can anyone explain the connection of the voltage divider in this image, why it's connected to A0? I put a red circle on the section that i don't understand.

The voltage divider reduces the battery voltage by a factor of $$\\frac{R2}{R2+R3} = \frac{1000}{2500} = 0.40\$$. This puts it in a range that allows the Arduino to measure it. 0 to 12.6 V (minus the diode drop) becomes 0 to 4.8 V, which can be measured by the ADC, which accepts 0 to 5 V.
• Why would there be a short circuit? The current through the resistors will be about $\frac{12\text{ V}}{2500\Omega} = 4.8\text{ mA}$. – Dave Tweed Feb 9 at 12:57