How long does a 9kg propane tank last on average when cooking with Arc Lite? 13 February 2026 11:46 Updated 9kg/20lb Propane Tank should last for around 35 hours on full heat. Related articles Can Arc Lite be used commercially or in my mobile pop-up? How do I clean the stone in Arc Lite? Why does Arc Lite not feature a thermometer? How long does Arc Lite take to heat up? How do I return an item that I no longer want?