GT POWER GTP-BH Battery Heater,warmers. LiPO battery perform at optimum when temperature is between 25 to 40 degree C. Adjustable temperature control with heater control (Same operation as MuchMore 3080). Wide wrap around heaters form a pouch for battery Or heaters can be used in a large LiPo sack. Operates from 7.4 to 12 volt input. Note: Temperature probe must be in position at all times. Do not exceed 45 deg C with Lipo battery, or swelling might accur. Wide heaters can be used on tyres etc.