EV Battery Pack SOC Tracking for Usage Estimation

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Solution Overview

Problem

Existing systems face challenges in estimating the usage status of electric vehicles without vehicle data, particularly in battery pack rental services where vehicle data such as speed and mileage are difficult to obtain.

Innovation Solution

A vehicle usage status estimation system that acquires time-series battery data from a removable battery pack during charging, identifies State Of Charge (SOC) transitions, and estimates running status based on these data to infer user behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vehicle data acquisition systems are installed in electric vehicles to monitor usage status, then measurement precision of usage status is improved, but device complexity increases

Engineering Contradiction:
Improveusage status measurement precisionVSAvoidvehicle system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the data acquisition function from the vehicle system and relocates it to the battery pack. The battery pack independently measures its own SOC (State of Charge) values and stores them, eliminating the need for vehicle-mounted terminals and complex data acquisition systems. This resolves the contradiction by achieving precise usage status measurement through a simpler, decentralized approach.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The battery pack performs self-monitoring and self-recording of its SOC values during charging and discharging cycles. The battery pack autonomously stores time-series SOC data in its own storage unit, eliminating dependency on external vehicle systems. This self-service mechanism achieves accurate usage status tracking without adding vehicle system complexity.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If vehicle-mounted terminals are used to record time-series vehicle information, then measurement precision of usage status is improved, but ease of operation deteriorates due to limited applicability

Engineering Contradiction:
Improveusage status measurement precisionVSAvoidsystem applicability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent makes the battery pack a universal data source that can serve multiple functions: power storage, SOC monitoring, and usage status recording. Since all electric vehicles with battery packs can utilize this approach, it eliminates the limitation of requiring specific vehicle-mounted terminal hardware. The battery pack becomes a multi-functional component that works across different vehicle types and rental models.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If battery packs are rented for short periods with frequent charging, then productivity of battery pack rental service is improved, but loss of information about long-term degradation increases

Engineering Contradiction:
Improvebattery pack rental turnoverVSAvoidlong-term degradation information
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent implements preliminary action by continuously recording SOC values at each charging cycle before the battery pack is returned. The time-series SOC data is stored in the battery pack's memory during each rental period, creating a cumulative historical record. This preliminary data collection ensures that even with frequent short-term rentals, the complete usage history is preserved for long-term degradation analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system establishes feedback by transmitting the accumulated time-series SOC data from the battery pack to the server after each charging cycle. The server processes this feedback data to calculate usage status and track degradation over time. This continuous feedback loop ensures that information is not lost despite frequent rental turnovers, as each charging cycle reinforces the historical record.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4657701A1Vehicle usage situation estimation system, vehicle usage situation estimation method, and vehicle usage situation estimation program
Publication Date: 2025.12.03 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP4657701A1 patent drawingFigure 1
  • EP4657701A1 patent drawingFigure 2
  • EP4657701A1 patent drawingFigure 3

AI summary

In a vehicle usage status estimation system (10), a data acquisition unit acquires, while a battery pack (30) currently or previously mounted on an electric vehicle (40) is connected to a charging apparatus (20), time-series battery data covering a period during which the electric vehicle (40) is used from the battery pack (30) via the charging apparatus (20). An SOC transition identification unit identifies a transition of SOC (State Of Charge) of the battery pack (30) since completion of previous charging of the battery pack (30) used in the electric vehicle (40), based on the time-series battery data. A running status estimation unit estimates a running status at a time of use of the electric vehicle (40) by referring to the transition of SOC.