# US 5,698,967 A · Battery management system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,698,967 A - Document ID: US5698967A - Status: Granted - Kind: A - Application number: 08/676,799 - Filed: 1996-07-08 - Granted: 1997-12-16 - Earliest claimed: 1995-04-03 - Assignees: Electrosource, Inc. - Inventors: Jose T. Baer; Bill C. Davis; Richard J. Blanyer - Web page: https://patentgrep.com/patent/US5698967A ## CPC - H02J 7/56: Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters - B60L 53/65: involving identification of vehicles or their battery types - B60L 58/12: responding to state of charge [SoC] - B60L 58/25: by controlling the electric load - H02J 7/50: acting upon multiple batteries simultaneously or sequentially - H02J 7/80: including monitoring or indicating arrangements - B60L 2250/12: by confirmation, e.g. of the input - B60L 2250/16: by display - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 90/12: Electric charging stations - Y02T 90/14: Plug-in electric vehicles - Y02T 90/16: Information or communication technologies improving the operation of electric vehicles - Y02T 90/167: Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV] - Y04S 30/14: Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing - Y10S 320/21: State of charge of battery - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y04S: SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A battery management system for management and control of a plurality of rechargeable batteries connected in series. A programmed central processing unit communicates with a plurality of battery modules and a bulk charger. Each of the battery modules includes a rechargeable battery, a sensor node including a plurality of battery sensors and a microcontroller that processes signals generated by the battery sensors, and a direct current charger. During a charging cycle the bulk charger provides a variable bulk charging current to the rechargeable batteries connected in series and each of the rechargeable batteries receive a charging current from individual direct current chargers positioned at each rechargeable battery. During the charging cycle, the voltage and temperature of the rechargeable batteries are monitored by the programmed central processing unit by means of the sensor nodes and the bulk charging current reduced by one half when any battery voltage reaches a predetermined clamping voltage. Once the bulk charging current is reduced to approximately 1 to 2 percent of the 3-hour discharge capacity for the rechargeable batteries, the bulk charger is turned off and the direct current chargers finish each battery charge independently. ## Claims ### Claim 1 A method for monitoring a rechargeable battery comprising: monitoring a temperature of said rechargeable battery; monitoring a voltage of said rechargeable battery; incrementing a high temperature second counter when said monitored temperature exceeds a predetermined maximum temperature for a predetermined time interval; incrementing a low temperature second counter when said monitored temperature is less than a predetermined minimum temperature for a predetermined time interval; incrementing a high voltage second counter when said monitored voltage exceeds a predetermined clamping voltage for a predetermined time interval; incrementing a low voltage second counter when said monitored voltage is less than a predetermined minimum voltage for a predetermined time interval; and storing said high temperature second counter, said low temperature second counter, said high voltage second counter, and said low voltage second counter in a memory. ### Claim 2 A method for monitoring a rechargeable battery comprising: monitoring a temperature of said rechargeable battery; monitoring a voltage of said rechargeable battery; and generating a high temperature warning signal when said monitored temperature exceeds a predetermined maximum operating temperature; generating a low temperature warning signal when said monitored temperature is less than a predetermined minimum temperature; generating a high voltage warning signal when said monitored voltage exceeds a predetermined clamping voltage; generating a low voltage warning signal when said monitored voltage is less than a predetermined minimum voltage; incrementing a high temperature second counter when said monitored temperature exceeds said predetermined maximum temperature for a predetermined time interval; incrementing a low temperature second counter when said monitored temperature is less than said predetermined minimum temperature for a predetermined time interval; incrementing a high voltage second counter when said monitored voltage exceeds said predetermined clamping voltage for a predetermined time interval; incrementing a low voltage second counter when said monitored voltage is less than a predetermined minimum voltage for a predetermined time interval; and storing said high temperature second counter, said low temperature second counter, said high voltage second counter, and said low voltage second counter in a memory. ### Claim 3 A method for monitoring a rechargeable battery, comprising: monitoring at least one operating condition of said rechargeable battery; for each operating condition of said battery, monitoring an elapsed time period during which said operating condition of said battery exceeds a predetermined value; for each operating condition of said battery, monitoring another elapsed time period during which said operating condition of said battery is less than another predetermined value; and for each operating condition of said battery, storing said elapsed time periods in a memory. ### Claim 4 (depends on 3) The method for monitoring a rechargeable battery of claim 3, further comprising: for each operating condition of said battery, generating a warning signal when said elapsed time period exceeds a predetermined time period; and for each operating condition of said battery, generating another warning signal when said another elapsed time period exceeds another predetermined time period.