Secondary cell state detector

• US 10,038,222 B2
• Filed: 07/26/2016
• Issued: 07/31/2018
• Est. Priority Date: 07/30/2015
• Status: Active Grant

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Takahashi, Yuichi
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Nasir, Taqi
• Application Number:
  US15/219,793
• Publication Number:
  US 20170033416A1
• Time in Patent Office: 735 Days
• Field of Search: 324426, 324430, 324432, 324433, 324382, 324409-411, 324678
• CPC Class Codes: B60K 6/22 characterised by apparatus, components or means specially adapted for HEVs
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60Y 2200/91 Electric vehicles
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2400/308 Electric sensors
• CPC Class Codes: H01M 10/4285 Testing apparatus
• 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 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/904 Component specially adapted for hev

Abstract

A condenser is connected to both electrodes of a secondary cell. A first switch is provided between a positive electrode of the secondary cell and a one-side plate of the condenser. An MCU turns ON the first switch when the secondary cell is in a first state to connect both electrodes of the secondary cell to both plates of the condenser, and then turns OFF the first switch. In addition, thereafter, the MCU detects a state of the secondary cell based on a differential voltage output from a differential amplifier circuit when the secondary cell is in a second state.

Claims

1. A secondary cell state detector that detects a state of a secondary cell, the secondary cell state detector comprising:

a condenser connected to both electrodes of the secondary cell;

a first switch provided between a one-side electrode of the secondary cell and a one-side plate of the condenser;

a first switch control unit turning ON the first switch when the secondary cell is in a first state to connect the both electrodes of the secondary cell to both plates of the condenser, and then turning OFF the first switch;

a differential amplifier circuit having a first input to which the one-side plate of the condenser is connected and a second input to which the one-side electrode of the secondary cell is directly connected, the differential amplifier circuit outputting a differential voltage of the first input and the second input;

a cell state detecting unit detecting the state of the secondary cell based on the differential voltage when the secondary cell is in a second state after the first switch control unit executes control;

a second switch provided between the both plates of the condenser;

a second switch control unit turning ON the second switch; and

an electrode-to-electrode voltage detecting unit detecting an electrode-to-electrode voltage of the secondary cell based on the differential voltage when the second switch is turned ON.