Detecting device and detecting method for monitoring battery module

• US 8,587,317 B2
• Filed: 03/26/2010
• Issued: 11/19/2013
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: National Chung-Shan Institute of Science and Technology
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Inventors: Liu, Chin-Chuan, Mei, Li-Yang, Yang, Fu-Kwo, Wu, Jong-Lin
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): MILLER, DANIEL R
• Application Number:
  US12/748,338
• Publication Number:
  US 20110234231A1
• Time in Patent Office: 1,334 Days
• Field of Search: 324425-437, 324/512, 324/522, 324/523, 324/525, 324/526, 324/750.3, 324/538, 324/555, 324605-609, 324/691, 324/704, 324/705, 324/706, 324713-718, 320116-123, 307/10.7
• US Class Current: 324/429
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

A detecting device and a detecting method for monitoring a battery module are provided. The battery module is electrically connected to a load and includes a first battery unit, a second battery unit and a connecting device. The connecting device connects the positive electrode of the first battery unit to the negative electrode of the second battery unit. The detecting device includes a shunt, a voltage detecting module and a control module. The shunt is serial connected between the battery module and the load to measures the load current. The voltage detecting module measures the voltage difference across the connecting device between the positive electrode and the negative electrode. The control module computes the equivalent resistance across the connecting device between the positive electrode and the negative electrode according to the load current and the voltage difference. Therefore, the hazard caused by aging of the electric circuit can be prevented by monitoring the equivalent resistance, which infers the change of the assembly quality.

Claims

1. An apparatus, comprising:

a battery module detecting device (1a) connected to a battery module (2a) of a circuit, the battery module detecting device (1a) for detecting a resistance of n−

1 connecting devices (23) of n battery units and three wires (31, 32, 33), wherein n≧

2, the circuit comprising;

the n battery units, represented by battery units 1, . . . n, serially connected via the n−

1 connecting devices (23), the n battery units comprising;

a battery unit 1 (21), comprising a first positive electrode (211) and a first output electrode (212); and

a battery unit n (22), comprising an nth negative electrode (221) and a second output electrode (222); and

the n−

1 connecting devices (23), connecting two electrodes of different polarities of two battery units neighboring each other of the n battery units by fixing on the two electrodes via two locking devices (24);

a shunt (11);

a load (3) powered by the battery module (2a);

wherein the three wires (31, 32, 33) comprise a first wire (31), a second wire (32), and a third wire (33), with one end of the load (3) connecting the first output electrode (212) of the battery unit 1 (21) via the first wire (31), and another end of the load (3) connecting the second output electrode (222) of the battery unit n (22) via the second wire (32) and the third wire (33), and detecting ends, each of the detecting ends fixed by a detecting end locking device (126);

wherein the battery module detecting device (1a) comprises;

the shunt (11), serially connecting the battery module (2a) and the load (3) for measuring a load current of the load (3) running through the n−

1 connecting device (23);

a voltage detecting module (12) connected to the shunt 11 for measuring a voltage between the two electrodes of each of the n−

1 connecting devices (23), as well as a voltage across each of the three wires (31, 32, 33), wherein the voltage detecting module (12) comprises;

an analog scanning switch (123), targeting two of the detecting ends (124, 125) of the plurality of detecting ends;

a millivoltmeter (122), measuring a voltage difference between electrodes of the two detecting ends (124, 125); and

an analog/digital converter (121), converting the voltage difference between the electrodes (211, 221) from an analog signal to a digital signal;

a control module (13) for receiving the digital signal converted by the analog/digital converter (121), wherein the control module (13) is configured to;

compute an initial equivalent resistance between the two detecting ends of each of the n−

1 connecting device (23), as well as for each of the three wires (31, 32, 33), based on an initial load current measured by the shunt (11) and an initial voltage difference measured by the millivoltmeter (122) and converted by an analog/digital converter (121);

record the initial equivalent resistance as a default resistance;

calculate a quality reference, based on the default resistance as well as an instant equivalent resistance output continuously by the control device (13);

compare the quality reference value and a default threshold;

start a protection function of the battery module detecting device when the quality reference is larger than the default threshold;

generate a visual output in text messages or equivalent illustrating images, or generate an audio output from a default buzzer of the battery module detecting device (1a); and

implement an optional cut-off to stop the power provided by the battery module (2a).

2. The battery module detecting device (1a) of claim 1, including a display (14) connecting the control module (13) for displaying the equivalent resistance.

3. The battery module detecting device (1a) of claim 1, including a plurality of protection resistors (127).