Wow… nearly a month since our last post. Anyway, when I got my Polar S625x in August last year, it came with Polar’s new WearLink transmitter, which has a far smaller plastic electronics module that their previous designs. The skin sensors are integrated into the strap. This makes it far more comfortable that their previous offerings, and more comfortable that most other HRM manufacturer’s designs. It also has a user-changable battery – a first (I think) for Polar.
About a month ago, the S625x starting playing up, giving zero HR readings, etc., but, at the same time giving good speed data. Oh, well, it’s the battery in the transmitter – thought it was a bit quick to run out after only 10 months, but never mind. Changed the battery – same results. Bought a new transmitter, thinking maybe my sweat was particularly corrosive and had somehow leaked into and damaged the electronics :-). Tried the new transmitter (and this is the vital bit) with the old strap – after all, it’s only an elastic strap, isn’t it. Same intermittent results. Last night, I changed the old strap for the new one that came with the new transmitter and, bingo!, works perfectly. Perhaps my sweat had destroyed some of the connections in the strap.