The Efest PRO C4 Charger is an easy and cost-effective way of changing the charger. The four-bay Efest PRO is powered by an AC wall plug and capable of simultaneously charging charge four batteries. Whilst charging one or two batteries simultaneously, the charging current will intelligently adjust to 1A. On the other hand, when charging three or four batteries simultaneously, it will adjust intelligently to 0.5A. The LED indicator light turns red when the battery is charging and green when fully charged. It can charge different types of 3.6V/3.7V lithium batteries commonly used in electronic cigarettes, flashlights, electric tools etc.