hyperion temp sensor
 

do you just lay the sensor pad on your pack to get the temp or what?

Look at it - the side opposite the side with the 3 screws goes down against the batt. The small square window on this side is where the temp pickup and it should be in contact with the batt surface.

I use a rubber band to give mine good contact and stay in one place, for accurate temps, you don't want the sensor moving around. Been pretty impressed with mine, its a huge improvement over the temp sensor made for the Ice charger, and seems to provide a reliable, timely temp.