How long does a thermometer battery generally last? I had a feeling my thermometer was playing up this morning as it keeps giving me different temps. ie If I take temp 3 times, with exactly the same placement, it will give me 3 different temps, all way different.

I went out today to get a new battery and couldn't find one, so I bought a new thermometer (cant live without it) This one is taking my temp at least 0.12 degrees higher than my old one.

Should I continue using my old one for the rest of this cycle, then swap to new one next cycle (hopefully I wont need it) or is it OK to just use the new one now?

I am in a bit of a dilemma, because if my old one is playing up my temps will be wrong and mess up my chart, but if I change to the new one that could mess up my chart too.

What to do???