This 8.5” by 11” by 0.25” thick dew heater pad helps with both problems. It sits underneath your laptop computer and warms it gently. This keeps the battery compartment temperature up to extend the battery life, and keeps the LCD screen warm enough to reduce or prevent image fadeout. The effect on the LCD screen is most pronounced if the screen is kept partially or nearly completely folded closed when not in use, so that all the gentle warmth rising from the computer body flows across the screen before dissipating into the cold night air. Leaving the computer screen in a fully open and upright position all night long reduces the amount of heat from the pad that flows over the screen and may limit the effectiveness of the heating pad.

The pad is made of a thick sheet of foam rubber with a thin sheet of rubberized fabric cemented to it. Imbedded between the sheets is a heater element made of a single thin strand of nichrome wire many feet long. The wire is laid in a maze-like pattern so that it warms the entire top (non-foam) surface of the heater pad. Since the pad is in direct contact with the bottom of your laptop, the warmth of the heater element is transmitted very effectively into the computer. The heater pad draws 3 amps at full power (power consumption at normal operating levels will generally be 40% to 60% less, as the normal standard controller setting is medium to low). It has a permanently attached 4’ power cord terminated by a male RCA plug for connection to the heater control unit.

The heater pad can also be used with a desktop PC that is exposed to cold temperatures, such as a computer work station in an observatory dome. Even if you don’t have a computer, it also makes a great seat warmer during long observing sessions.