BBT thermometers

[redclover]

So, when they don't beep anymore, even after about five minutes...is that a sign that the thing can't be trusted?
It still gives read outs, and decent temps, but is it accurate if it doesn't really beep? Like maybe ONCE this week has it beeped, but only once when I had passed out again and who knows how long it took...
should I get a new one? I have had this one probably three years...Are they really that disposable?

[finnegansmom]

The battery could be dying to be honest. I don't know if you can replace the battery in them though. I've gone a through a few in 3 years, although most fall victim to my toddler.