Battery Specification Item name: Replacement worx battery 20V Applicable models：WA3578 WA3575 WA3525 WA3520... Battery Capacity: 3.5Ah Battery Voltage: 20 Volts Battery Type: Lithium-ion Color: Black Compatible With: for Worx 20V Cordless Drill WX169L for Worx WX176L.9 20V Switchdriver 2-in-1 Cordless Drill for Worx WX508L.9 20V Recip Saw for Worx WX530L.9 20V 6-1/2" Circular Saw Bare for Worx WX543L 20V Jigsaw for Worx WX550L 20V AXIS 2-in-1 Reciprocating Saw for Worx WX801L Mini-Cutter for Worx WG320.9 JawSaw 20V PowerShare Cordless Electric Chainsaw for Worx WG545.9 AIR 20V Multi-Purpose Blower/Sweeper/Cleaner for Worx WG921.1 Cordless 20V 12” Trimmer Battery Maintenance: If the lithium battery is not used for a long time, it should maintain 50%~60% capacity, and should be recharged every 3 months, and charged and discharged every six months. When the instrument is not in use, be sure to remove the battery and store it in a dry and cool place. Do not mix batteries with metal objects to prevent metal objects from touching the positive and negative terminals of the battery, causing a short circuit, damaging the battery or even causing danger.