Method for determining the starting ability of a starter battery in a motor vehicle

• US 6,268,712 B1
• Filed: 09/26/2000
• Issued: 07/31/2001
• Est. Priority Date: 09/26/2000
• Status: Expired due to Term

• Current Assignee: Clarios Germany GmbH & Co., KGaA (Michael Tojner, PhD, LLD)
• Original Assignee: VB Autobatterie GmbH
• Inventors: Meissner, Eberhard, Laig-Hörstebrock, Helmut
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/669,275
• Time in Patent Office: 308 Days
• Field of Search: 320/132, 320/136, 320/DIG.22, 324/427, 324/430, 324/432, 324/433
• US Class Current: 320/132
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• 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

Abstract

A method for determining the starting ability of the starter battery in a motor vehicle. The current and voltage of the storage battery are measured before starting is begun, shortly after starting is begun and at short intervals of time during the starting procedure. The current/voltage value pairs for each instant are used to calculate a resistance value and the quantity of charge drawn from the storage battery, and the rate of rise in the resistance values as a function of the quantity of charge drawn is used to derive a measure of the availability of the storage battery during the starting procedure. In particular, the gradient ΔRQ of the internal resistance as a function of the quantity of charge drawn and the turn-on internal resistance R_E are stored in an arithmetical memory as a field as a function of the charge state or of the equivalent no-load voltage (U_R) and the battery temperature and are compared with already recorded values or typical normal values.

Claims

1. A method for determining the starting ability of a starter battery in a motor vehicle comprising:

measuring current and voltage of the storage battery before starting is begun;

measuring current and voltage of the storage battery shortly after starting is begun;

measuring current and voltage of the storage battery at predetermined intervals of time during starting;

calculating a resistance value and the quantity of charge drawn from the storage battery from current/voltage value pairs for each measurement; and

determining a measure of availability of the storage battery during starting, based on the rate of rise in the resistance values, as a function of the quantity of charge drawn.

2. The method as defined in claim 1, wherein the voltage and current are measured before starting (U_VS,I_VS) and no later than about 0.02 sec. after starting is begun (U_E,I_E).

3. The method as defined in claim 1, wherein the time intervals between the voltage and current measurements are between about 0.001 and about 0.1 sec.

4. The method as defined in claim 1, wherein the time intervals between the voltage and current measurements are approximately 0.01 sec.

5. The method as defined in claim 1, wherein a voltage and current pair (U_S,I_S) is measured in a time range in which turn-on resistance R_E and resistance R_S=Δ

U_S/Δ

I_S are substantially the same, and R_S is determined as the gradient of a current/voltage line at two respective instants which are separated by a relatively long measurement period to determine an equivalent no-load voltage U_R.

6. The method as defined in claim 5, wherein the measurement period is approximately 0.2 sec.

7. The method as defined in claim 1, wherein a charge state of the battery is determined from no-load voltage before starting.

8. The method as defined in claim 1, wherein a gradient Δ

RQ of internal resistance as a function of quantity of charge drawn and turn-on resistance R_E are stored in an arithmetical memory and compared with prerecorded values or preselected normal values.

9. A method for determining the starting ability of a starter battery in a motor vehicle comprising:

measuring current and voltage of the storage battery before starting is begun;

measuring current and voltage of the storage battery shortly after starting is begun;

measuring current and voltage of the storage battery at predetermined intervals of time during starting;

calculating a resistance value and the quantity of charge drawn from the storage battery from current/voltage value pairs for each measurement;

measuring a voltage and current pair (U_S,I_S) in a time range in which turn-on resistance R_E and resistance R_S=Δ

U_S/Δ

I_S are substantially the same, and determining R_S as the gradient of a current/voltage line at two respective instants which are separated by a relatively long measurement period to determine an equivalent no-load voltage U_R for determining the charge state of the storage battery;

storing a gradient Δ

RQ of internal resistance as a function of quantity of charge drawn and turn-on resistance R_E in an arithmetical memory and comparing the gradient with already recorded values or preselected normal values;

determining a measure of availability of the storage battery during starting, based on the rate of rise in the resistance values as a function of the quantity of charge drawn.