100% Compatible with original battery,Original Part Number: 300-03864-1.NOT FOR 300-03866. | Compatible Part Numbers: Ademco Honeywell Ademco Honeywell LYNXRCHKITHC LYNXRCHKIT-HC K5109 781410403291 55026089 WALYNX-RCHB-SC WALYNXRCHBSC LYNXRCHKIT-SC LYNX Voice, LYNXR, LYNXR24, LYNXR24-SP LYNXR-2FR, LYNXR-2SIA, LYNXR-ENSIA LYNXR-EN, LYNXR-I, LYNXR-IE, LYNXR-EN, LYNXR-I, LYNXR-IE, LYNXSIA Plus, LYNXR-ISIA, LYNX LYNXRCHKITSHA LYNXRCHKIT-SHA, LYNX Plus, LYNX Touch, LYNX Touch SIA, LYNXR CFLYNXR-EN, LYNXR-2, LYNXRIEN-A, LYNXRIEN-EA, LYNXR-IFR | Capacity: 1100mAh / Volts:7.2Volts / Type: Ni-MH,Dimension: 84.65 x 51.42 x 14.50mm,Package included:1 x 300-03864-1 battery | Please Check Part Number - Battery Connector - 2 Prong.A new battery pack must be fully charged before first use. (this may take 24-48 hours) | Note: Make sure the connector of your original battery is identical to the one shown on the photo.for safety during shipping it comes with little charge. Battery will fully charge once it is installed in the unit.