DEWALT XR 4.0Ah Li-Ion Battery Technology offers extended runtime and optimised power to complete applications quickly. LED State of Charge Indicator helps manage pack charging. Lightweight design provides the user with upgraded 4Ah Power without increasing the size or weight over the 18V 3Ah battery pack. No memory effect and virtually no self-discharge for maximum productivity & less downtime. Compatible with all DEWALT XR Li-Ion 18V Tools. Excellent electrical characteristics. No memory effect.