The DEWALT XR Slide Li-Ion Battery Pack has a compact, lightweight design. No memory effect and virtually no self-discharge for maximum productivity and less downtime. A LED state of charge indicator helps to manage charging/working time. Compatible with all 10.8V and 12V XR slide on tools and most XR chargers. The DEWALT DCB124 XR Li-ion Battery offers up to 50% more runtime than the DCB127 (10.8V 2.0Ah Li-ion) and is approximately the same size and weight, giving you more power with the same ergonomics. This is for a twin pack of batteries