The Stanley FatMax® V20 Li-ion charger is ready to go to work whenever you are, charge any Stanley FatMax V20 battery, capable of fast charging a 2Ah battery within 60 mins. The Stanley FatMax V20 18V Cordless System batteries can be interchanged with your V20 power tools, using a common new and improved 18V Lithium-ion battery for longer runtime and power to get the job done. The higher the amp hour the longer the battery will last before it needs to be recharged.