The global shift towards electric vehicles (EVs) has underscored the importance of effective battery management. Cell balancing and State of Charge (SoC) estimation are two critical aspects of this.
Cell balancing ensures uniform charge levels among cells, reducing variations, enhancing efficiency, and prolonging battery life. SoC estimation, on the other hand, prevents battery overcharging and over-discharging. It aims to provide users with the available runtime of an EV.
The global EV battery management system market, valued at 1.42 billion U.S. dollars in 2021, is projected to grow at a compound annual growth rate (CAGR) of 17.2% from 2022 to 2027, reaching 5.67 billion U.S. dollars in 2027.
This underlines the increasing acknowledgment of the significance of cell balance and State of Charge (SoC) estimates in Electric Vehicle (EV) battery management. The article will also explore how SoC estimation helps prevent battery overcharging and over-discharging in EVs while informing users about the available runtime.
Overview of Patents on Cell Balancing and SoC Estimation in EV Battery Management
Here’s an in-depth overview of some notable patents on cell balancing and SoC estimation in EV battery management:
Cell Balancing Patents
- US20190109468A1: This patent relates to a method for battery cell balancing in a battery system. It applies a combination of active and passive cell balancing to optimize cell balancing under different conditions. The main purpose of such systems and methods is to maintain homogeneous conditions between all cells of the battery, thus allowing optimal operation in terms of efficiency, stored energy, and lifetime.
- US20190199106A1: This discloses a battery cell balancing system that contains a switch mode circuit employing voltage sensors across the cells and current sensors on the balancing legs to enable reliable and efficient cell balancing during battery charge. The signal from the current sensor is provided to the controller, which modulates the switch mode dividers (SMDs) based on signals from the current sensors to limit the current through the balancing legs to no more than a threshold current magnitude.
SoC Estimation Patents
- CN111337839A: This patent discloses a system and a method for SOC estimation and balance control of an electric vehicle battery management system. The system comprises an acquisition module, a conversion module, a communication module, a SOC estimation module, and a balance module. The method realizes balance management by calculating the SOC value of the battery when the electric quantity of the battery is inconsistent, is safe to use, and prolongs the battery’s service life.
- CN112557907A: This patent discloses a SOC estimation method of an electric vehicle lithium-ion battery based on GRU-RNN. It involves collecting historical data on the lithium-ion battery in the charging and discharging process, preprocessing it, and constructing a training and test set.
The GRU-RNN network model is trained using the training set, and the trained model is evaluated using the test set. If the model doesn’t meet the requirements, parameters are adjusted, and the model is retrained until the SOC estimation precision and robustness meet the requirements. This method makes SOC estimation more convenient and effective.
Companies Implementing Cell Balancing and SoC Estimation in EV Battery Management
Here are the companies and their patented implementations in the field of SoC estimation and cell balancing:
- EV Power Australia, REAP organization, American Edition Company, Beijing Significant Power Technology, and Harbin Guantuo Power Equipment Company: These companies have advanced Battery Management System (BMS) goods, likely including patented technologies related to SoC estimation and cell balancing.
For instance, Beijing Significant Power Technology has a patent for a full-life-cycle joint estimation method for SOC and the capacity of a power battery.
This method uses real-time battery system aging data, extracts temperature change parameters under multiple aging stages based on a model, and establishes a battery model containing information on the multiple aging stages.
- Texas Instruments: Texas Instruments offers an automotive-grade battery management IC with active cell balancing capabilities. This company has been associated with the Impedance Track™ battery-fuel-gauging technology, a proprietary algorithm that learns battery capacity and impedance over time to accurately calculate the state of charge (SOC) and remaining capacity.
The product, known as bq76PL536-Q1, is based on TI’s PowerPump charge-shuttling technology. They also have a reference design for a 16-cell lithium-ion battery active balance system. - Lithium Balance AS: Lithium Balance AS holds a patent for a method for battery cell balancing in a battery system. The patent applies a combination of active and passive cell balancing to optimize cell balancing under different conditions. The system includes a cell monitoring block configured to monitor the voltage or a related quantity across individual cells in a battery cell module.
Ongoing Patent Applications in EV Battery Management
The growth of the EV sector in EV battery management has led to a surge in patent applications for new EV inventions. Companies across the globe are racing to file patents for advancements in battery technology.
For example, between 2005 and 2018, the European Patent Office reported an increase of 14% in the international patent families for electricity storage, of which 88% related to battery technology.
In the context of EV powertrains in India, a total of 529 patents were filed in the given period.
In 2020, Suzuki and Piaggio submitted numerous inventions to enhance the placement of batteries in electric two-wheelers.
One of the recent inventions filed in 2021 is IN202141012385A, which is owned by TVS. This patent specifically deals with the arrangement of two electric motors in the powertrain of vehicles with two or three wheels.
End Note
The significance of cell balancing and State of Charge (SoC) estimation in EV battery management cannot be overstated. The outlined patents showcase cutting-edge solutions, such as active and passive cell balancing methods and advanced algorithms for precise SoC estimation. Companies like EV Power Australia, Texas Instruments, and Lithium Balance AS are at the forefront, implementing these patented technologies in their Battery Management Systems (BMS).
As the EV sector continues to surge, ongoing patent applications indicate a fervent race for innovation in battery technology. On this site, we provide a comprehensive resource for further exploration and insights into the latest advancements in EV battery management through patented technologies. We club together patents that address the same problem, providing a streamlined and efficient way to navigate through the vast landscape of patents. It is handy for R&D teams, helping them generate insights from patents and drive innovation.
To learn about the world of patented technologies in EV battery management, visit our website for more details and up-to-date insights. Your journey toward innovative EV solutions begins here.