Apparatus and method for carrying out diagnostic tests on batteries and for rapidly charging batteries

• US 6,259,254 B1
• Filed: 07/26/1999
• Issued: 07/10/2001
• Est. Priority Date: 07/27/1998
• Status: Expired due to Term

• Current Assignee: Midtronics Incorporated
• Original Assignee: Midtronics Incorporated
• Inventors: Klang, James K.
• Primary Examiner(s): Tso, Edward H
• Application Number:
  US09/361,487
• Time in Patent Office: 715 Days
• Field of Search: 324/426, 324/427, 324/429, 324/430, 324/433
• US Class Current: 324/427
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/386 using test-loads
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

A method and system for performing automatic and rapid diagnostic testing and charging of a battery. The diagnostic test unit utilizes a charger combined with a rapidly variable load. After inputting battery characteristics including the cranking rating (CCA or CA) and the temperature of the battery, a diagnostic ramp procedure is utilized to provide an instantaneous current versus voltage analysis to determine the instantaneous cranking value (i.e., the single crank capability at full charge) of the battery being tested. If the instantaneous cranking value of the battery is above a level determined acceptable, a sustained discharge is carried out to tax the capacity of the battery.

At the end of the constant current discharge, the current is again to determine a loaded cranking value which simulates the battery power after multiple cranking attempts. If the loaded cranking value is below a desired percentage of the cranking rating, then the battery is put into charge. If a battery cannot be acceptably charged within the time of a given number of diagnostic probes, the battery is deemed to be a bad battery. The charging steps utilized during the diagnostic testing, as well as any charging of batteries determined to be good, utilizes a novel interactive stepping procedure which allows batteries determined to be good to be recharged in a minimum period of time without overheating the battery.

Claims

1. In a battery diagnostic system, a method for performing a diagnostic test on a battery to determine if the battery is in a condition acceptable for recharging the battery, the method comprising:

automatically determining an instantaneous cranking value for the battery; and

if the instantaneous cranking value for the battery is determined to be above a predetermined level, automatically performing the further steps of;

performing a sustained discharge of the battery to generally tax the capacity of the battery;

determining a loaded cranking value for the battery that generally simulates battery power after multiple cranking attempts; and

if the loaded cranking value for the battery is above a desired percentage of a rated cranking value for the battery, deeming the battery to be in good condition for charging.

2. The method as recited in claim 1, wherein the step of automatically determining the instantaneous cranking value for the battery further comprises using a cold cranking rating and temperature of the battery in connection with a diagnostic ramp procedure to perform an instantaneous current versus voltage analysis on the battery.

3. The method as recited in claim 2, further comprising the step of accepting from a user input device the cold cranking rating of the battery and the temperature of the battery.

4. The method as recited in claim 2, further comprising the step of accepting from a temperature sensor the temperature of the battery.

5. The method as recited in claim 1, wherein the step of determining the loaded cranking value for the battery further comprises the step of ramping a current discharged from the battery from a first level to a second, lower level.

6. The method as recited in claim 1, wherein the step of determining the loaded cranking value for the battery further comprises the step of ramping a current discharged from the battery from a first level to a second, higher level.

7. The method as recited in claim 1, wherein the step of performing a sustained discharge of the battery further comprises the step of selectively placing an adjustable load in electrical connection with the battery.

8. The method as recited in claim 1, if the loaded cranking value is below a desired percentage of a rated cranking value for the battery, repeating the diagnostic test over a predetermined number of iterations.

9. The method as recited in claim 1, further comprising the step of sensing if the battery is connected to the system, and in response to a sensed connection, prompting a user for a characteristic of the battery, and using the characteristic in performing the step of automatically determining the instantaneous cranking value for the battery.

10. The method as recited in claim 1, further comprising the step of sensing the open circuit voltage of the battery and, if the open circuit voltage is below a predetermined value, performing further diagnostic tests on the battery.

11. A readable-medium having processor executable instructions for use in performing a diagnostic test on a battery to determine if the battery is in a condition acceptable for recharging the battery, the instructions performing the steps comprising:

automatically determining an instantaneous cranking value for the battery; and

if the instantaneous cranking value for the battery is determined to be above a predetermined level, automatically performing the further steps of;

performing a sustained discharge of the battery to generally tax the capacity of the battery;

determining a loaded cranking value for the battery that generally simulates battery power after multiple cranking attempts; and

if the loaded cranking value is above a desired percentage of a rated cranking value for the battery, deeming the battery to be in good condition for charging.

12. In a battery diagnostic and charging system, a method for performing a diagnostic test on a battery to determine if the battery is in a condition acceptable for recharging the battery, the method comprising:

automatically determining the instantaneous cranking value for the battery; and

if the instantaneous cranking value for the battery is determined to be above a predetermined level, automatically performing the further steps of;

performing a sustained discharge of the battery to generally tax the capacity of the battery;

determining a characteristic of the battery under load; and

if the determined battery characteristic is within a desired percentage of a rated characteristic for the battery, recharging the battery.

13. The method as recited in claim 12, wherein the characteristic of the battery is a loaded cranking value for the battery that generally simulates battery power after multiple cranking attempts.

14. The method as recited in claim 13, wherein the step of determining comprises determining if the loaded cranking value for the battery is above a desired percentage of a rated cranking value for the battery.

15. In a battery diagnostic and charging system, a method for operating the system comprising:

accepting from a user input device a characteristic of a battery; and

in response to the input of the characteristic, automatically performing the further steps of;

determining if the battery is in a condition to be recharged; and

if the battery is in a condition to be recharged, recharging the battery.

16. The method as recited in claim 15, wherein the characteristic is the cold cranking rating of the battery.

17. The method as recited in claim 15, further comprising the step of conditioning the battery after the battery has been generally recharged.

18. A method for performing a diagnostic test on a battery, the method comprising:

discharging the battery from a first predetermined amperage down to a base level amperage to determine a single crank capability of the battery;

discharging the battery from a second predetermined amperage down to the base level amperage to determine a multiple crank capability of the battery; and

determining a state of the battery using the single crank capability and the multiple crank capability.

19. The method as recited in claim 18, wherein the second predetermined amperage is higher than the first predetermined amperage.

20. The method as recited in claim 18, wherein the step of determining the state of the battery comprises deriving a resistance activation voltage for the battery using the single crank capability and multiple crank capability.