From the instruction manual, concerning "12 Volts":

"The 12 volt Comp Heater should only be powered from an 11.1v 3S Lipo battery, a 12v gel cell or car battery, or 12v power supply. Check power output and make sure it does not exceed 12V. When charging batteries only charge to 12V.

CAUTION: Some 12V power supplies produce a higher voltage. This will damage the heating element. Make sure maximum output does not exceed 12 volts.

WARNING: Do not use a power source higher than 12 volts.

Make sure your batteries are properly charged and balanced if using a Lipo battery. Follow all manufacturers’ warnings and directions.

We recommend using an 11.1v Lipo battery. Place battery inside your starter box separate from the battery used to power your starter box."



My starter battery peaks at 14.70 volts. Most "12 Volt" batteries have a higher voltage than "12 Volts".

Seems the confusion comes in from the label we've associated with batteries used to power our hobby needs and in the automotive world. While they are indeed "12 Volts", they often have peak and residual voltages well higher than 12 Volts.