Battery testing method and device

• US 4,290,021 A
• Filed: 05/01/1979
• Issued: 09/15/1981
• Est. Priority Date: 05/01/1978
• Status: Expired due to Term

• Current Assignee: Crucible Societe Anonyme 14 Rue Alringen Luxembourg
• Original Assignee: Bernardus J. Bout, Jacob J. Theron, Jacobus P Van Wyk, Michael D De Lange
• Inventors: Van Wyk, Jacobus P., Bout, Bernardus J., Theron, Jacob J., De Lange, Michael D.
• Primary Examiner(s): Moore, David K.
• Application Number:
  US06/035,274
• Time in Patent Office: 868 Days
• Field of Search: 324/426, 324/427, 324/429, 324/430, 324/432-435, 320/40, 320/48, 328/132, 328/151
• US Class Current: 324/429
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention provides apparatus for testing the condition of a battery comprising a load, means to connect the battery to the load for a predetermined interval and means to measure the battery voltage at least at the end of the interval.

The invention further extends to apparatus for successively testing the condition of a plurality of batteries comprising means for connecting one of the batteries to a given load for a predetermined interval, means for measuring the voltage of the battery at least at the end of the interval, means for determining the condition of the battery from the voltage measurement, and control means for connecting a fresh battery to the load and repeating the testing of the batteries until all the batteries are tested.

The invention also provides a method of testing the condition of a battery including the steps of connecting the battery in a charged condition to a load for a predetermined interval, and measuring the battery voltage at least at the end of the interval.

Claims

1. A method of testing the condition of a battery, comprising the steps of sequentially:

(a) connecting up the battery to a charger for a period of time sufficient to fully charge the battery;

(b) sensing the battery voltage with a first level detector;

(c) if the battery voltage sensed with the first level detector is greater than a predetermined minimum, withdrawing a predetermined charge from the battery by (c1) effecting operation of a timer, (c2) upon effecting timer operation connecting up the battery to a non-resistive constant current load, and (c3) drawing constant current from the battery with the load for a predetermined period of time determined by the timer;

(d) while the battery is connected to the constant current load, sensing the voltage thereof and comparing the sensed voltage to a voltage tapped from a constant voltage source; and

(e) operating an indicator if the battery voltage measured in step (d) is greater than the voltage tapped from a constant voltage source.

2. A method as recited in claim 1 comprising the further steps of, for a given type of battery, empirically determining the value of the constant current load, the time interval of the timer, and the voltage tapped from the constant voltage source, to provide proper predetermined values for steps (c2), (c3), an (d) for that particular battery type;

and adjusting the values of the timer, constant current load, and tapped voltage to effect proper testing of that particular battery type.

3. A method as recited in claims 1 and 2 wherein step (c2) is practiced by connecting up the battery to a transistor, and varying the bias applied to the transistor to adjust the value of the constant current being withdrawn.

4. Apparatus for testing the condition of a battery, comprising:

a first level detector for sensing battery voltage;

a timer;

a non-resistive constant current load;

a tapped constant voltage source;

a second level detector for sensing battery voltage;

voltage comparator means; and

circuitry means for;

interconnecting a battery to said first level detector;

interconnecting said first level detector to said timer so that said timer will be actuated if the battery voltage sensed by said first level detector is greater than a predetermined minimum;

interconnecting said timer and the battery with said constant current load so that said load will draw constant current from the battery for a predetermined period of time determined by the timer;

interconnecting said second voltage detector with the battery so that said constant current load; and

interconnecting said tapped constant voltage source and said second voltage detector with said comparator means to determine whether or not the sensed voltage is greater than a predetermined amount set by said tapped constant voltage means.

5. Apparatus as recited in claim 4 wherein said non-resistive constant current load comprises a transistor, and means connected to said transistor for varying the bias applied thereto to thereby adjust the value of the constant current being withdrawn.

6. Apparatus as recited in claim 5 further comprising means for adjusting the time interval of said timer, and the voltage tapped from said constant voltage source, to provide proper predetermined values for a given type of battery to be tested.

7. Apparatus as recited in claim 4 comprising means for adjusting the time interval of said timer, the value of the constant current being withdrawn by said constant current load, and the voltage tapped from said constant voltage source, to provide proper predetermined values for a given type of battery to be tested.

8. Apparatus for testing the condition of a battery, comprising:

means for withstanding a predetermined charge from the battery, said means including a transistor which comprises a constant current load, a timer for controlling the time said transistor draws a constant current load from the battery, and means connected to said transistor for varying the bias applied thereto to thereby adjust the value of the constant current being withdrawn thereby;

a battery voltage sensing means;

a voltage comparator; and

circuitry means interconnecting said battery voltage sensing means and said voltage comparator to determine whether or not the sensed voltage is greater than a predetermined amount.