So the sensor naturally makes exactly what to do and reliably measures STRIDELENGTH & "revolutions". What I miss is the possibility to use the sensor also on the stationary bike. I'm pretty sure that this option the marketing allgewertigen fell victim and we are the only reason we buy an additional sensor;) there was not an answer to my such request from the manufacturer :( but ok, I use the sensor to 80% while running and there are no complaints :) For battery life I can make no useful information. The calibration of the automatic I left up and lie there on surveyed route at +/- 5m, to me that's ok. But along with my V800 I use the GPS function of the clock for the distance measurement. From sensor I use "only" step number and length (Cadence & stride length) I feel the sensor neither size nor gewichtsmaessig as conspicuous.