Changed battery and it doesn't detect transmitter. Everything else works and the transmitter gets detected by our treadmill, so I know it works.?

Transforms with bluetooth device (e.g. computer, MP3 player, PSP) with 3.5mm audio-out jack into a Bluetooth-capable music streaming solution with no additional drivers required. Supported Bluetooth profiles: A2DP. This transmitter can connect the device automatically ,you no need do anything ,just need press the on and off button until there is blue and red lights lternating flicker then it is can connect. and don't try to connect your mobile phone ,because this transmitter it is connect the earphone ,speaker . Bluetooth-capable music streaming solution with no additional drivers required. Bluetooth receiver: Pair it with your bluetooth-enabled phone, and connect it with your headset or speaker (without bluetooth function),when it show BYL-918,you just put in 0000 will be ok. Amazon com Charm sonic Portable Transmitter Connected to 3 5mm Audio...

Transmitter Battery
The estimated average battery life span of the transmitter is 2500 hours of use. If you suspect that the transmitter battery
has run out, contact your authorized Polar Service Center for a replacement transmitter. Polar recycles used transmitters;;;