Two-Stage Battery Charging for Electric Vehicles

Solution Overview

Problem

Electric motor vehicles face challenges in starting promptly in cold weather due to battery temperature issues, and existing charging methods may not ensure sufficient charge before the scheduled start time, leading to inadequate power for unscheduled driving.

Innovation Solution

A charge method for electric motor vehicle batteries that includes detecting residual charge, calculating maximum charge time, and implementing a two-stage charging process: a first charge during vehicle stop and a second charge to ensure battery warm-up by the scheduled start time, with optional adjustments for temperature and unscheduled driving scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the battery is charged only until the calculated charge start time based on driving-start time, then the battery can be warmed up sufficiently by the driving-start time, but the residual charge quantity may be insufficient for unscheduled driving before the driving-start time

Engineering Contradiction:

Improvebattery temperatureVSAvoidresidual charge quantity

Core Design Contradiction:

TemperatureVSQuantity of substance

Solution Approach 1:

The charging process is divided into multiple stages: a first charge stage that provides sufficient charge quantity for unscheduled driving, and a second charge stage that warms up the battery to proper temperature by the driving-start time. This segmentation allows simultaneous achievement of both sufficient charge quantity and adequate temperature.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first charge is executed preliminarily before the driving-start time to ensure sufficient residual charge quantity is stored in the battery. This preliminary charging action guarantees that even if driving starts earlier than planned, there is enough charge available.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If the battery is charged for a long period to ensure sufficient charge quantity, then the residual charge quantity becomes sufficient, but the battery may not be warmed up sufficiently in cold season

Engineering Contradiction:

Improveresidual charge quantityVSAvoidbattery temperature

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The charging process is divided into multiple stages: a first charge stage that provides sufficient charge quantity for unscheduled driving, and a second charge stage that warms up the battery to proper temperature by the driving-start time. This segmentation allows simultaneous achievement of both sufficient charge quantity and adequate temperature.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The charging action continues from the first charge stage into the second charge stage without interruption. The second charge stage extends the charging process to ensure the battery reaches proper temperature while maintaining sufficient charge quantity, thus continuously performing the useful action of charging.

Inventive Principle:

Principle #20Continuity of useful action

3Quantity of substance

If charging is started immediately when the vehicle stops, then the charge quantity can be maximized, but the battery temperature may be insufficient for prompt driving start in cold weather

Engineering Contradiction:

Improvecharge quantityVSAvoidbattery temperature

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The charging process is divided into multiple stages: a first charge stage that provides sufficient charge quantity for unscheduled driving, and a second charge stage that warms up the battery to proper temperature by the driving-start time. This segmentation allows simultaneous achievement of both sufficient charge quantity and adequate temperature.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first charge is executed preliminarily before the driving-start time to ensure sufficient residual charge quantity is stored in the battery. This preliminary charging action guarantees that even if driving starts earlier than planned, there is enough charge available.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8188705B2Charge method and device of battery for electric motor vehicle

Publication Date: 2012.05.29 MAZDA MOTOR CORP

AI summary

The present invention is a charge method of a battery for an electric motor vehicle, in which a battery is charged by an outside electric source. A residual charge quantity of the battery is detected before charging. A maximum-quantity charge time Ttotal which is required for the residual charge quantity of the battery becoming the maximum quantity is calculated based on detection result. A driving-start time tds of the electric motor vehicle is estimated. A first charge is executed so as to be started from a driving stop of the electric motor vehicle, continued for a period of time which is shorter than the maximum-quantity charge time Ttotal, and completed before the driving-start time tds. A second charge is executed so as to be started after the first charge is completed and completed at the driving-start time tds.