Method for charging an electric storage battery

• US 5,896,023 A
• Filed: 10/09/1997
• Issued: 04/20/1999
• Est. Priority Date: 10/18/1996
• Status: Expired due to Term

• Current Assignee: VB Autobatterie GmbH
• Original Assignee: VB Autobatterie GmbH
• Inventors: Richter, Gerolf
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US08/947,715
• Time in Patent Office: 558 Days
• Field of Search: 320/104, 320/162, 320/164, 322/28, 322/25, 322/27, 322/37, 324/429
• US Class Current: 320/104
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

Abstract

A method for charging an electric storage cell, in particular a lead acid battery, as the starter battery in a motor vehicle, involves the generator voltage being controlled, using the charge state of the accumulator as a controlled variable, the charge state being derived from a measurement of the no-load voltage of the storage cell at the instant of the zero crossing of the current flowing in the storage cell. The measurement of the no-load voltage is carried out within a period of from 0.1 ms to 1 ms after a zero crossing of the current in the storage cell.

Claims

1. A method for charging an electric storage cell with a generator, wherein the generator voltage is controlled using the charge state of the storage cell as a controlled variable, the charge state being derived from a measurement of the no-load voltage of the storage cell approximately at a zero crossing of the current flowing in the storage cell.

2. The method of claim 1, wherein the measurement of the no-load voltage is carried out within a period of from 0.1 ms to 1 ms after a zero crossing of the current flowing in the storage cell.

3. The method of claim 2, wherein a charging no-load voltage is measured after charging has been interrupted and a discharging no-load voltage is measured after discharging has been interrupted, wherein a plurality of the measured no-load voltages are processed to generate a mean, wherein:

the generator voltage is increased when the mean of the no-load voltages is dropping;

the generator voltage is decreased when the mean of the no-load voltages is rising; and

no change in the generator voltage takes place when the charging and discharging no-load voltages behave differently.

4. The method of claim 3, wherein:

the measurements of the no-load voltage occur at intervals of from about 0.1 to about 10 minutes; and

a mean used to calculate changes in the generator voltage is generated from about 10 to 20 measurement intervals.

5. The method of claim 1, wherein a charging no-load voltage is measured after charging has been interrupted and a discharging no-load voltage is measured after discharging has been interrupted, wherein a plurality of the measured no-load voltages are processed to generate a mean, wherein:

the generator voltage is increased when the mean of the no-load voltages is dropping;

the generator voltage is decreased when the mean of the no-load voltages is rising; and

no change in the generator voltage takes place when the charging and discharging no-load voltages behave differently.

6. The method of claim 5, wherein:

the measurements of the no-load voltage occur at intervals of from about 0.1 to about 10 minutes; and

a mean used to calculate changes in the generator voltage is generated from about 10 to 20 measurement intervals.

7. The method of claim 1, wherein:

the measurements of the no-load voltage occur at intervals of from about 0.1 to about 10 minutes; and

a mean used to calculate changes in the generator voltage is generated from about 10 to 20 measurement intervals.