    AST RESEARCH, INC.          TECHNICAL BULLETIN # 0997               10-13-94

              ASCENTIA 900N BATTERY BECOMING HOT WHILE CHARGING ON AC ADAPTER

    PROBLEM:       The Ascentia 900N external battery case can become hot to the
                   touch while charging on the AC adapter.

    CAUSE:         The temperature is within the normal design specifications of
                   the type of battery used in the Ascentia 900N.

                   The recommended method of ending a charge cycle with Nickel-
                   Metal Hydride batteries involves a temperature fluctuation
                   (delta) of approximately 20 degrees C or about 68 degrees F
                   from beginning to end.  Thus, if the battery is charged in a
                   normal room temperature environment, the internal charging
                   temperature will reach 43 degrees C or about 109.4 degrees F.
                   Since there is some additional heat build up after
                   termination, the battery temperature can be expected to
                   increase by several degrees.

                   If however, the charging algorithms are reset by removing and
                   reinserting the AC adapter, and charging begins when the
                   battery is near 40 degrees C (the upper limit in order to
                   start charging), the charging will terminate on a maximum
                   allowable temperature of 50 degrees C.  There have been some
                   extreme cases where the thermal overrun can reach an internal
                   battery temperature of 58 degrees C or about 136.4 degrees F,
                   at which time the plastic case will be uncomfortable to the
                   touch.

    SYSTEMS
    AFFECTED:          AST                                                REVISION
                   PART NUMBER           DESCRIPTION                        LEVEL

                   501299-2XX      ASCENTIA 900N 4/50 CS10                   All
                   501300-3XX      ASCENTIA 900N 4/50 CT9                    All
                   501302-2XX      ASCENTIA 900N 4/75 CS10                   All
                   501304-3XX      ASCENTIA 900N 4/75 CT10                   All

    SOLUTION:      It is recommended that the battery area of  the Ascentia 900N
                   notebook not be placed on a person's lap or exposed skin while
                   the unit is charging while connected to the AC adapter.  If
                   the battery case is excessively hot while charging on AC
                   adapter, replace the battery.

    CAUTION:       In no case will AST Computer be liable for damage to the
                   system or loss of data caused by the improper implementation
                   of this technical bulletin.