Here is our rechargeable lithium-ion battery at 12 Volts DC, 5200mAh. It has a built-in controller with four intensity levels.All you need is your heating equipment. You plug it directly into one of the two outputs of the battery. Turn it on, press the red button for two seconds, a red LED will tell you that the battery is working at maximum. Repeat the red button to change intensity to get the best comfort possible.Red Led100% intensity (maximum)Orange Led75% intensityGreen Led50% intensity Blinking Green Led25% intensity