Recently, my Suunto Ambit doesn’t pick-up heart rate data consistently from stock Suunto ANT Heart Rate Belt as usual. It create a box shape heart rate graph as move29582215, result incorrect PTE (Peak Training Effect) and display wrong recovery time calculation.
Decide to change the battery in centre piece of belt, battery model of the belt is CR2032, as stated in official site: Comfort Belt Battery Kit. Battery cover located at the back, easy to open with tiny edge of tool such as flat head screwdriver. I took out the old Maxell battery, replaced with new purchased Sony CR2032, tested it and signal is now strong by transmit heart rate in “real-time”.