So I always used the cheapo glass one that came with my hovabator for my reptile eggs, and have always gotten good hatches over the yrs. Sinc I havent used the hb in a couple years, I decided to check the accuracy of the unit with my digital thermometer with probe. It was 2 degrees off from the glass one, no big deal just split the differnce. Well I went to get a hygrometer to moniter humidity, and got a digital one that has a thrmo also, figured it couldnt hurt. Now I have 3 different readings, lowest temp from brand new thrmo at 98.7, mid temp from glass thrmo at 100, high temp from probe at 101.4-7. I even put all three right next to each other just to see, and same thing. The glass one has no batt, the combo has new batt, and the probe is probably1.5 yrs old. Do you think the battery is the difference? Am I close enough, the average temp being 100 +/- 1? the eggs have already been in for a day, so I guess its too late to woory now.