Ok, so we never fully developed this code out or added it to Github.
I wrote this test program a while back to connect with the MCP3021 chip that measures the voltage (http://ww1.microchip.com/downloads/en/DeviceDoc/21805B.pdf). The chip is connected on the I2C bus of the BrickPi+, and measures the voltage through a voltage divider circuit.
# Voltage reading on BrickPi+
# I2C Connection Using the MCP3021
# Future work:
# Convert the raw data to something meaningful.
bus = smbus.SMBus(1) # SMBUS 1 because we're using greater than V1.
address = 0x48
i2c_return = bus.read_i2c_block_data(address, 0)
print "Result: " + str(i2c_return)
print " Failed."