Polar F7--frequent battery change?

sleepyjen

Many years ago--when I first lost the weight I'm losing now--I bought a Polar F7 HRM. I loved it, used it all the time. When I started exercising again two years ago, I sent it out for a battery change. Last week, I changed it myself, no problems. This week, the readout says the battery is low again. Does anyone else have this problem? I don't know if the HRM itself has seen better days, or if its sensors aren't as sensitive, or if the battery I got at Radio Shack was so subpar that after a half-dozen hourlong jaunts, it's dying. I appreciate your input! I love my F7 and would hate to have to get another, but will if I have to.