This page has a schematic of the sensor module. Note the 100 Ohm resistor in series with the IR LED. At 5 volts the LED will draw approximately 32 mA. The other LEDs on the board probably account for most of the other 11 mA.
Using consumption rate of 0.7
Using consumption rate of 0.7 I get about 40 hours. Is that more our less sounding right?
Thanks. 0.7 was just something I read that gives a rough discount of true battery life. This seems to confirm what I'm seeing, having this sensor on kills my battery in about 2.5 days or so.