Hi Mem,
I probably covered fix rates a bit in my last post, but to clarify, we're definitely keen on hourly (or less) fixes. Our static tests are revealing some intriguing battery life projections for five minute fixes, which seem to be the best of both worlds in terms of accuracy (very good average DOP values & Sat #) and operational time (~8secs - 10secs to get a fix with a hold-off value of five). We've run the logger for 7 days at a five minute fix rate using two Duracell DL123 batteries in series (~1550mA capacity) and voltage only dropped from 6.4v to 5.89v. The SF GPS logger tolerates voltages between 4v and 7v, so we were very pleased with these preliminary results, as we might get a couple of weeks of deployment at least out of this set-up. Sleep draw of the SF logger really seems to be the major limiting factor (1.5mA) in deployment projections.
Cheers