The 7.4V, 900mAh Pearstone EN-EL20 Lithium-Ion Battery Pack replaces the Nikon EN-EL20 battery. Small and lightweight, this rechargeable lithium-ion battery can be charged or discharged at any time without developing memory effects, meaning it will never lose its ability to hold a full charge. It has a voltage of 7.4V and a capacity of 900mAh.