Specification: 1: 18V 5.0Ah Li-Ion backup battery for DeWalt 18V XR tool 2：LED indicator allows you to check the state of battery （When the LED display has only one grid, please charge it in time. Please do not exhaust the battery.） 3：No memory effect on the battery 4:Perfect compatible with all Dewalt XR 18V Power Tools 5:lightweight ,easy to use 6:Over-Charge protection / Over-discharge protection / Over-current protection / Short-circuit protection 7：100% product satisfaction and One year warranty.