They have an LED state of charge indicator to help manage pack charging. They have a lightweight design that provides the user with upgraded 5.0Ah Power without increasing the size or weight over the 18 Volt 3.0Ah battery pack. No memory effect and virtually no self-discharge for maximum productivity & less downtime. They have protection against overheating, overloading and deep discharge conditions which increases the overall battery life. Compatible with all DEWALT XR Li-Ion 18 Volt Tools.