Patent EP0731545A2 successfully refreshed from Google Patents.
EP0731545A2
Expired / Lapsed
EP
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Circuit and method for battery charge control
Assignee: Motorola Solutions Inc
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Filing: 1996-02-29
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Granted: —
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Expires: 2016-02-29
Abstract
Abstract A battery charge control circuit (10) senses the charge condition of cells in a battery pack (12, 14, 16, 18) using measurement circuit (51). Upon detection of a single under-voltage cell, the charge control circuit is placed in a sleep mode. Pack sense circuit (240) senses when the battery pack is placed in a charger. If circuit (10) was in a sleep mode, it is awakened. If any cell is measured over-voltage, the status is checked versus the other cells. If all the cells are over-voltage, the battery is considered balanced. If one or more cells are not over-voltage, control circuit (32) activates a discharge transistor (212, 214, 216, 218), discharging the cell within a hysteresis voltage below the over-voltage limit. Charge balancing of cells is continued until the cells are within a programmable hysteresis voltage of each other.
Inventors
- 👤 Troy Lynn Stockstad
- 👤 Thomas D. Petty
- 👤 Renwin J. Yee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 09:35
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/50; H02J7/52; H02J7/54; H02J7/56; H02J7/60; H02J7/64; H02J7/685; H02J7/90; H02J7/96
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
91 words
A battery charge control circuit coupled to a first battery cell, comprising: a measurement circuit (51) coupled for receiving a first battery voltage from the first battery cell and providing a status signal upon sensing an overvoltage condition in the first battery cell; a control circuit (32) responsive to said status signal for decoding a first battery control signal from said status signal; and a discharge circuit (212, 214) coupled across the first battery cell and operating in response to said first battery control signal for discharging the first battery cell.
Claim 2
Independent Claim
58 words
A method of discharging a battery cell, comprising the steps of: measuring a first battery voltage from the battery cell and providing a status signal when the battery cell is in an overvoltage condition; decoding said status signal for providing a first battery control signal; and discharging the battery cell in response to said first battery control signal.
Claim 3
Dependent Claim
128 words
A battery charge control circuit coupled to a battery cell for sensing an over-current supplied to the battery cell, comprising: a current sense resistor (11) having a first terminal coupled to a first power supply conductor and having a second terminal coupled to the battery cell; an over-current detector circuit (35) having an input coupled between said first and second terminals for sensing the over-current supplied to the battery cell and having an output for providing a driving signal; and a transistor (41) having a gate coupled for receiving said driving signal, a source coupled to the battery at a third terminal operating at a reference potential, and a drain coupled to an output terminal for providing a simulation of a thermistor in response to said driving signal.
Claim 4
Independent Claim
38 words
A method for simulating a thermistor in a battery charge control circuit, comprising:: sensing an over-current in a battery cell; detecting said sensed over-current; and activating a thermistor simulation device in response to said detection of said over-current.
Claim 5
Dependent Claim
252 words
A battery charge control circuit coupled to a battery cell, for sensing a connection of the battery cell to a battery charger, comprising: a measurement circuit (51) coupled for receiving a first battery voltage from the battery cell at first and second terminals and having an output for providing a first status signal upon sensing an undervoltage condition in the battery cell; a first logic circuit (60) having an input coupled to the output of said measurement circuit and having an output; a second logic circuit (62) having first input coupled for receiving said first status signal, a second input, and an output responsive to said first status signal; a first transistor (26) having a gate coupled to the output of said first logic circuit, a source coupled to the battery charger at a third terminal, and a drain; a second transistor (24) having a gate coupled to the output of said second logic circuit, a drain coupled to said drain of said first transistor, and a source coupled to said second terminal; and a detector circuit (240) having a first input coupled to said source of said first transistor for detecting a first voltage, a second input coupled to said output of said first logic circuit, a third input coupled for detecting a voltage at said second terminal, and an output coupled to said input of said second logic circuit and responsive to a differential of said first voltage and said voltage at said second terminal for providing an activation signal.
References Cited (Backward Citations)
No citation records indexed.
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