Snow Joe EcoSharp 40-Volt 4Ah Lithium-Ion Replacement Battery - Maintains consistent power throughout entire cycle Runs at full power until "empty" - power doesn't fade. Provides 25 to 40 minutes of whisper quiet run time. Fuel Gauge Indicator Lights lets you Easily monitor the charge capacity while battey is in use. Fits all Snow Joe and Sun Joe cordless iON models --- Battery charger (#iCHRG40) sold separately