An automotive AC recharge should last for years if the system is sealed and in good condition. Refrigerant is not intended for consumption during normal use, so you should not need frequent recharges. If your AC needs refrigerant every season, every few months, or shortly after a previous service, there is likely a leak or another system problem. Small leaks can occur at seals, hoses, the condenser, evaporator, or compressor. The exact lifespan of a recharge depends on the size of the leak, vehicle age, driving conditions, and repair quality. A professional AC service should include pressure checks and leak detection to ensure the recharge lasts as long as possible, rather than requiring repeated short-term fixes.