Dynamic Battery Charging Method Optimizing C-Rates by SOC

Solution Overview

Problem

Conventional battery charging methods that aim for fast charging result in increased heat dissipation and rapid battery degradation, leading to reduced output and capacity.

Innovation Solution

A battery charging method that determines optimal charge C-rates for each State of Charge (SOC) section by comparing voltage capacity ratios, allowing for fast charging while minimizing battery degradation by maintaining performance similar to slow charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If constant current charging is performed with a high C-rate to achieve fast charging, then charging time is reduced, but heat dissipation increases and battery degradation accelerates

Engineering Contradiction:

Improvecharging speedVSAvoidheat dissipation and battery degradation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The charging process is segmented into multiple SOC sections (0-20%, 20-50%, 50-80%, 80-100%). Each section uses a different C-rate optimized for that specific charge level, allowing fast charging in mid-range SOC while using lower C-rates at critical levels (0-20% and 80-100%) to minimize heat and degradation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The C-rate is made dynamic rather than constant. The charging current automatically adjusts based on the current SOC level, transitioning between different C-rates as the battery charges. This dynamic adjustment optimizes charging speed while preventing excessive heat and degradation at critical charge levels.

Inventive Principle:

Principle #15Dynamics

2Loss of time

If constant current charging is performed with a high C-rate to achieve fast charging, then charging time is reduced, but battery capacity and output are reduced due to degradation

Engineering Contradiction:

Improvecharging timeVSAvoidbattery capacity and output

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The charging process is segmented into multiple SOC sections (0-20%, 20-50%, 50-80%, 80-100%). Each section uses a different C-rate optimized for that specific charge level, allowing fast charging in mid-range SOC while using lower C-rates at critical levels (0-20% and 80-100%) to minimize heat and degradation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The C-rate is made dynamic rather than constant. The charging current automatically adjusts based on the current SOC level, transitioning between different C-rates as the battery charges. This dynamic adjustment optimizes charging speed while preventing excessive heat and degradation at critical charge levels.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP2947748B1Battery charging method and battery management system therefor

Publication Date: 2018.04.18 SAMSUNG SDI CO LTD

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AI summary

There are provided a battery charging method. The method includes (a) obtaining voltage capacity ratios for a reference charge C-rate and N (N is an integer of 1 or more) charge C-rates which are larger than the reference charge C-rate, the voltage capacity ratio being defined as a ratio of a voltage variance to a capacity variance depending on a change in SOC (state of charge) of a battery when the battery is charged with each of the C-rates, (b) comparing the voltage capacity ratio of the reference charge C-rate with each of the voltage capacity ratios of the N charge C-rates, and then setting a charge C-rate among the N charge C-rates so that a difference in voltage capacity ratio is minimized for each of SOC sections, and (c) charging the battery with the charge C-rate that is set for each of the SOC sections.