Designed to be power efficient and compatible with all Ryobi 18V ONE+™ lithium batteries whilst also being fast and intelligent. With a lightning-fast 4A charging rate, you can charge your batteries one at a time until all 6 are fully charged. And, thanks to the convenient indicator lights, you'll always know what's going on with your battery's charge. The "ready-to-go" light will even let you know when your battery has reached 80% capacity. But that's not all! This charger is also equipped with advanced monitoring technology that keeps a close eye on your battery's voltage and temperature to ensure long-lasting durability.