Method of equalizing the voltages of the individual cells of storage batteries

• US 4,331,911 A
• Filed: 02/17/1981
• Issued: 05/25/1982
• Est. Priority Date: 05/22/1978
• Status: Expired due to Fees

• Current Assignee: Robert H. Park
• Original Assignee: Robert H. Park
• Inventors: Park, Robert H.
• Primary Examiner(s): HICKEY, ROBERT
• Application Number:
  US06/234,884
• Time in Patent Office: 462 Days
• Field of Search: 320/2, 320/3, 320/8, 320/14, 320/15, 320/17, 320/18, 320/20, 320/39, 320/40
• US Class Current: 320/119
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 320/19 Charger status, e.g. voltmeter

Abstract

There is disclosed a method of equalizing the voltages of the individual cells of a storage battery that consists in the steps of,

1. providing a single input circuit type of d.c. to d.c. converter incorporating multiple output circuits equal in number to the number of cells of the battery to which it is planned that the converter will make connection, with the converter so designed and employed that, with its input circuit connected to the terminals of the battery, and one of each of its output circuits connected across one of each of the cells of the battery, flow of cell equalizing current will hold low so long as the downward departures of the voltages of the battery'"'"'s cells from average cell voltage hold below a prescribed index value.

2. providing, via method of converter design and employment, and choice of the above referred to index value, so that, for a given type, size, and prior condition of use of a battery, employment of the converter as in step 1 above can be expected to provide a cost-effective way to both favorably affect the equality of the battery'"'"'s cell voltages, and avoid cell voltage reversal during battery discharge under contemplated conditions of the battery'"'"'s use.

3. providing to connect one of each of the output circuits of the converter across one of each of the individual cells of the battery.

4. providing so that when the battery is in active use the input circuit of the converter will be energized from the battery'"'"'s terminals.

5. providing a means of indicating when the extent of inequality of the cell voltages of the battery is such as to cause converter input current to exceed a preset value.

Claims

1. The method of equalizing the voltages of the individual cells of a storage battery which consists in the steps of,providing a single input type of d.c. to d.c. converter incorporating output circuits equal in number to the number of cells of the battery to which it is planned that the converter will make connection, with the converter so designed and employed that, with its input circuit connected to the terminals of that battery, and one of each of its output circuits connected across one of each of the cells of the battery, flow of cell equalizing current will hold low so long as the downward departures of the voltages of the cells from average cell voltage hold below a prescribed index value.providing via method of converter design and employment, and choice of the above referred to index value, so that, for a given type, size, and prior condition of use of the battery, employment of the battery as set forth in step (1) above can be expected to provide a cost-effective way to both favorably affect the equality of the battery'"'"'s cell voltages, and avoid cell reversal during discharge under contemplated conditions of the battery'"'"'s use,providing to connect one of each of the output circuits of the converter across one of each of the individual cells of the battery,providing so that when the battery is in active use the input circuit of the converter will be energized from the battery'"'"'s terminals.

2. A control system adapted for use in the charging of storage batteries of a given type, which incorporates a single input circuit type of d.c. to d.c. converter incorporating multiple output circuits equal in number to the number of cells of the type of battery to which it is planned that the output circuits of the converter will make connection, with the converter so designed that, with its input circuit connected to the terminals of the battery, and one of each of its output circuits connected to one of each of the cells of the battery, flow of cell equalizing current will hold low so long as the downward departures of the voltages of the battery'"'"'s cells from average cell voltage hold below an index value that has been so chosen that employment of the converter as a means of equalizing the voltages of the individual cells of batteries of the said given type can be expected to provide a cost effective way of both favorably affecting the equality of the voltages of the battery'"'"'s cells, and avoiding cell reversal under contemplated conditions of battery use.