Portable heaters require battery sizes capable of delivering continuous high power for heating elements while maintaining safety. Battery sizes for portable heaters typically favor high-capacity prismatic or multi-cell cylindrical packs that support steady discharge and thermal management. Proper sizing balances runtime with weight and safety controls such as thermal cutoffs and BMS integration. SUNJ ENERGY supplies cells with stable chemistry, robust cycle life, and strict quality certifications suitable for heating applications. We advise OEMs on pack architecture, ventilation, and safety testing so portable heaters achieve reliable warmth, compliant transport, and user-safe operation.