Battery Connection

Battery connection and voltage monitoring with Arduino and voltage divider.

Key components of power draw:

Component	Max Power Draw [W]
4 Motors	81.6
Raspberry Pi	12.8
Kinect	12.0
Total	106.4

At 7.4V a maximum of 12.8A could be drawn from the battery meaning a cable size of 14AWG is required.

Battery State Monitoring

Notes on monitoring the battery volatge as an indication of charge level using the Arduino via a voltage divider.

Voltage Divider

The Arduino M0 Pro operates at 3.3V so to read the battery voltage it must be scaled down using a voltage divider. The batteries used will not go above 10V so the following resistor values are used:

• R1 = 100k ohms
• R2 = 47k ohms

At 10V input the output would be 3.2V.

\[ V_{out} = V_{in} \cdot \frac{R_2}{R_1 %2B R_2} \]

Voltage divider

Battery Interface

The volatge can be monitored convieniently using the balance pins.