My wife was delighted with this Christmas present and it motivates her to swim and be more active. However the watch has already become unreliable, causing her much disappointment. I have had the battery tested and replaced by a jeweller. The old battery was ok, We’ve done everything in the Nokia helpline, spoken to Nokia as well - so it must be that the watch is at fault. Odd that Amazon does not make it very easy to return. No return link against the purchase.