No I replaced it when I received it a few weeks agois the battery on the way out ?
Yes I did that. Seems to work initially then after about 30 mins cycling (after sweating maybe) it stops giving a read out on my Garminwet the back of it, or your cleavage, before fitting?
i actually lick mine before i startIt could be that in the cooler temps you're not sweating enough and the contacts are drying out. Try re-wetting the contacts and if that works a more "permanent" solution may be electrolytic gel (as used with ECG monitors).