"Recharge" is another name for "refill." Your air conditioner is charged with enough refrigerant upon manufacturing to last its entire lifespan. Despite common misconceptions, refrigerant isn't something that "runs out" like gasoline does from a car. If you're told that your air conditioner needs a recharge, then that means you have a refrigerant leak. Yes, you need a recharge, but that leak must also be located and repaired so your air conditioner can function as it should.