Browse Prior Art Database

Battery Memory Effect Detection System

IP.com Disclosure Number: IPCOM000112988D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Mito, T: AUTHOR [+3]

Abstract

Disclosed is a devise for detecting battery memory effect in a battery powered apparatus. The devise detects it by monitoring battery parameters while the battery (or battery pack) is discharged.

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Battery Memory Effect Detection System

      Disclosed is a devise for detecting battery memory effect in a
battery powered apparatus.  The devise detects it by monitoring
battery parameters while the battery (or battery pack) is discharged.

      Fig. 1 shows an example of normal discharge characteristic of a
NiCd battery.  Fig. 2 shows an example of memory effect.  In Fig. 2,
there is a voltage drop (2) between start (1) and end (3) of
discharge.  Thus, voltage changes suddenly if a NiCd battery, which
has memory effect, is discharged.  The devise is located in the
battery or in the apparatus, and it monitors voltage while the
battery is discharged.  If the device detects the drop, it regards
this symptom as memory effect.  At this time, the devise ignores
voltages over B and below A in the figures since voltage moves
rapidly in the ranges and it's hard to distinguish between memory
effect and normal curve.

      After detecting memory effect, the devise takes an action to
eliminate it.  In some apparatus, a devise refreshes the battery
automatically to remove it.  And, in another apparatus, a devise
notify user of the symptom so that user can take a right action.

      Technology of the battery isn't limited to NiCd.  NiMH, or
others are also applicable.  Battery parameter isn't limited to
voltage.  Temperature or other battery parameters can be used since
it depends on battery technology.