To ensure the maximum life out of a new battery,  there are some best practices which must be followed as general maintenance for Nickel Cadmium Ni-MH Power Tool / Saws / Drill Batteries .

    * The battery will perform best if it is charged at room temperature. Do not charge in temperatures below 400F or above 1050F. Under these conditions, the battery will not take a full charge, and may be permanently damaged.

    * If the battery is hot, let the it sit out of the charger for a least 2 hours until the battery is at room temperature. Otherwise, immediately place the battery pack in the charger.
    * Do not try to discharge the battery beyond the point where the tool no longer performs with the power and torque needed for the job, because it may cause permanent damage which will prevent the battery from taking a full charge.  

    * Do not tape trigger on the machine to discharge the battery.

    * Store the battery in a cool, dry place. If temperatures exceed 1200F, it may reduce the battery life.
    * Periodically charge the battery overnight to take full advantage of the 3-Stage Charging System for optimum runtime and battery life.