Electronic battery tester

• US 6,806,716 B2
• Filed: 01/29/2004
• Issued: 10/19/2004
• Est. Priority Date: 04/08/1999
• Status: Expired due to Fees

• Current Assignee: Jamey Butteris, Kevin I. Bertness
• Original Assignee: Jamey Butteris, Kevin I. Bertness
• Inventors: Butteris, Jamey, Bertness, Kevin I.
• Primary Examiner(s): Tibbits, Pia
• Application Number:
  US10/767,945
• Publication Number:
  US 20040183540A1
• Time in Patent Office: 264 Days
• Field of Search: 324/426, 324/427, 324/428, 324/429, 324/430, 324/431, 324/432, 702/63
• US Class Current: 324/426
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/379 for lead-acid batteries
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: G01R 31/386 using test-loads
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 6/5044 Cells or batteries structurally combined with cell condition indicating means
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An electronic battery tester includes a calibration interface. A microprocessor is configured to calibrate the battery tester by coupling to a calibrator through the calibration interface.

Claims

1. An electronic battery tester for testing a battery comprising:

a source configured to apply a signal to terminals of the battery through first and second connections of a Kelvin connection to the battery;

a differential amplifier having an inverting input, a non-inverting input and a difference input;

a first capacitor and a first resistor configured to couple a first terminal of the battery to the inverting input of the differential amplifier and thereby form a third connection at the Kelvin connection;

a second capacitor and a second resistor configured to couple a second terminal of the battery to the non-inverting input of the differential amplifier and thereby form a fourth connection of the Kelvin connection;

an electrical connection between the differential output and the inverting input of the amplifier which includes a third resistor;

a fourth resistor electrically connected to the non-inverting input differential;

an analog to digital converter coupled to the differential output of differential amplifier;

a microprocessor configured to determine a condition of the battery as a function of an output of the analog to digital converter in response to the signal applied to the battery by the source.

2. The apparatus of claim 1 including a clock coupled to the microprocessor.

3. The apparatus of claim 1 including a memory coupled to the microprocessor.

4. The apparatus of claim 1 wherein the first capacitor and first resistor are connected in series.

5. The apparatus of claim 1 wherein the source comprises a current source.

6. The apparatus of claim 1 wherein the source includes a voltage source and a switch.

7. The apparatus of claim 1 wherein the condition of the battery is a fraction of a rating of the battery.

8. The apparatus of claim 1 wherein the condition of the battery is a fraction of a rating of battery conductance.

9. The apparatus of claim 1 including a display to provide an output indicative of the battery condition.

10. The apparatus of claim 9 wherein the display comprises an LED.