Browse Prior Art Database

Expanded Battery Type Recognition Method

IP.com Disclosure Number: IPCOM000109403D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Mamiya, J: AUTHOR [+3]

Abstract

Disclosed is a method of recognition for different types of rechargeable battery. A rechargeable battery is used as a power source for a notebook personal computer, and a Nickel Metal Hybrid (Ni-MH) battery has been recently developed. This battery has higher capacity than a Nickel Cadmium (Ni-Cd) battery and may be used together for a longer operation time for a machine. In case two different types of battery are attached to a personal computer, the machine shall distinguish the type of battery for charging or indicate the capacity remaining. The recognition is mechanically done by a switch provided in the machine as usual, but the method described herein need not require any additional part.

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Expanded

Battery

Type Recognition Method

       Disclosed is a method of recognition for different types
of rechargeable battery.  A rechargeable battery is used as a power
source for a notebook personal computer, and a Nickel Metal Hybrid
(Ni-MH) battery has been recently developed.  This battery has higher
capacity than a Nickel Cadmium (Ni-Cd) battery and may be used
together for a longer operation time for a machine.  In case two
different types of battery are attached to a personal computer, the
machine shall distinguish the type of battery for charging or
indicate the capacity remaining.  The recognition is mechanically
done by a switch provided in the machine as usual, but the method
described herein need not require any additional part.

      The figure shows the circuit for battery recognition.  It uses
the circuit for battery temperature sensing which is certainly
necessary for a rechargeable battery and expands the function to
recognize the battery type.  One chip micro-computer carrying out
power management finally recognizes the type of battery based on the
voltage value on BT output.  The voltage of BT output (VBT) varies
according to the resistor (R) provided in the battery pack and the
On-Off state of switch SW1 and SW2.  Here, if SW1 and SW2 would be
controlled as shown in the table, VBT is calculated on each state.
- State-1:
      VBT = VCC X RTH / ( R1 + RTH )
      RTH :  Resistance of the thermistor (TH)
- State-2:
    ...