FWIW, I use only Energizer Lithium cells in both the base station and the outside temp/humidity sensor. Never had a problem. Currently I am using the Ultimate Lithium cells. Run time is well over a year. The brand is LaCrosse Technology although this model is long since obsolete. Certainly a repeatable purchase! About my only complaint is that the recording is stopped at -30C temp and 20% humidity. nothing lower.
current temp at 1830 is -24.6C and dropping. sigh. another 'shiver me timbers' night.
Good point... I definitely should double-check which batteries I put in there. I might have put cheapies as I haven't bought batteries in a while. The sensor has been a little picky in locations and I thought this model was probably a little finicky from the start since I got it during a super-special rebate (30$ instead of 70-80$). Why didn't I even check the batteries beats me, though... I think mine too is rated for -30C and I'll still definitely get a backup glass thermometer as we hit less than that a few times already this year, which I haven't seen often in my life.
On another related note, my dad once read an article about a meteorologist that was much more accurate in yearly predictions than just about anyone else; He figured the average temperature should be influenced by the Sun's activity cycles. He compared data from yearly weather and sun activity cycles and bang! They matched up. Right now the sun is supposed to be at it's 11 year peak, but this is the calmest peak astronomers have seen since the very early 1900's (just about 1900 to be precise). This could definitely explain the cold spell we're experiencing.