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.