When I put the belt (after 1 yart of using with no problem) the watch not recoganized it and it is not sense the pulse,what should I do?, if it battery, what typeof battery?

Tx in adavnce

Tech Specs:

Band Type:

Plastic 

Altimeter:

No 

Barometer:

No 

Compass:

No 

Stopwatch:

Yes 

Chronograph:

Yes 

Thermometer:

No 

Heart Rate Monitor:

Yes 

PC Compatible:

Yes 

Waterproof:

Water resistant to 50m 

Backlight/ Electroluminescent:

Yes 

Alarms:

Target zones, audible and visual 

Size:

Medium to large 

Recommended Use:

Running, cycling, aerobic activities, strength training 

Warranty:

2 Years