Polar FT4....Need HELP!

littlecaponey2

I have had my Polar FT4 for over a year now and have never had to change the batteries in it. Today I went to the gym with my mother and she also had hers on. Mine was given me trouble and kept telling me to check my transmitter and calculating my HR really low, which resulted in saying I had a low calorie burn. Could this be because my mother and I were in arm distance of each other with the same FT4 on? Or do you think it was more just wash my band a little better for tomorrow's workout? Or do you think my battery is getting low in either the watch or the transmitter?

I have spin in the morning and when it doesn't work right, it messes with my focus.