What can I do to make my GPS respond to the heart rate monitor strap?

The Egde 305 uses a sensor to monitor the heart rate and a protocol called ANT+ to monitor and record the sensor characteristics. The problem may not be with the batteries or the software. The problem with such devices are that the sensors start to read only when it is in contact with your skin. Since you have used the device for one year , the strap would have lost its contact with your skin which in turn makes no contact with the Edge device.This mainly happens because your strap must have encountered foreign particles and contamination due to various possibilities like sweat , humidity , dust clogging in between the strap which unfortunately you would not have noticed. The strap is similar to a cloth and it needs a wash after few uses. Hand wash both the hard and soft strap heart rate monitors in cold water. Use only a tiny amount of mild detergents, such as dish-washing liquid. Using an substantial amount of detergent may cause damage to the strap itself. Hand wash at least every 5 uses. This would end your problem and the strap would get going with its sensor working perfectly. Make sure every time that the strap makes contact with your skin for the sensors to function . As EDGE 305 is a discontinued product we may not get the replacement for the parts so taking care of devices is a must as it just needs a few washes and its ready to serve you again and again.But do make sure you never clean the accessory using a washing or drying machine.Enjoy the device, spread the smile .