Each location in the county could have a different minimum ambient temperature. Thus, the Thermal Battery can accommodate various concentrations of propylene glycol. The Thermal Battery has a Glycol Concentration Sensor built-in which, in correlation with the zip code of the installation, verifies the concentration specific to that location. If inadequate, a message will pop up on the display. When a unit is ordered for drop shipment, the appropriate volume of glycol will be prefilled at the factory based on the zip code. The cost for this will be billed separately. In addition, glycol kits will also be available for purchase for use in the field.