See attached spreadsheet for a calculator to determine rough estimates for battery life for the Yabby GPS.
Note the average time to GPS fix varies with the logging period - more frequent logs means that the GPS module is downloading fresh aiding data, and stays 'hot', so it will more easily acquire a subsequent fix.
In general around 60s for a 'cold' start (logging period above 2hrs) and 8-12s for a 'hot' start (logging periods below 1hr)
You can also enter your real world device data from the Device Counters saved in OEM (average this across a few devices) to get a more accurate estimate.
To get to the Device Counters, follow the Details link in OEM
The counters are at the bottom of the page:
There are many factors that determine how long batteries will last, do not take this calculator as a guarantee, it is only meant as a guide.