Temperature Sensors for EV Battery Monitoring

Abstract Lithium-based batteries (LiBs) are integral components in operating electric vehicles to renewable energy systems and portable electronic devices, thanks their unparalleled density, minimal self-discharge rates, favorable cycle life. However, the inherent safety risks performance degradation of LiB over time impose continuous monitoring facilitated by sophisticated battery management (BMS). This review comprehensively analyzes current state sensor technologies for smart LiBs, focusing on advancements, opportunities, potential challenges. Sensors classified into two primary groups based application: optimization. Safety sensors, including temperature, pressure, strain, gas, acoustic, magnetic focus detecting conditions that could lead hazardous situations. Performance optimization such as optical-based electrochemical-based, monitor factors charge health, emphasizing operational efficiency lifespan. The also highlights importance integrating these sensors with advanced algorithms control approaches optimize charging discharge cycles. Potential advancements driven nanotechnolo... Read More

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Temperature measurement apparatus for battery modules that improves assembly efficiency and accuracy of temperature sensing. The apparatus has a holder with an alignment hole, a substrate with a temperature sensor, and protection members on both sides. A support member aligns the substrate with the hole. This prevents random movement of the sensor during assembly. Insulating members between the battery and terminals further prevent sensor misalignment. This reduces errors by fixing the sensor position and simplifying assembly compared to double-sided soldering.

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Battery cell design and pack protection to prevent thermal runaway in lithium-ion batteries. The battery cell has temperature labels at different positions. If the temperature difference between them exceeds a threshold, it indicates an abnormal state. When detected, the cell's charging/discharging switch is turned off to prevent further use, and a fire extinguisher inside the cell activates to prevent thermal propagation.

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Method for detecting electrical fault states in removable battery packs using integrated temperature sensors. The method involves measuring the temperature of the battery pack using a first monitoring unit with integrated sensors, and measuring the temperature of individual cells using temperature sensors within the battery pack. The pack's monitoring unit evaluates both temperatures and adapts charging/discharging currents based on the combined data. If the cell and pack temperatures differ by more than a threshold, it indicates local temperature differences. This enables more accurate compliance with cell specifications and prevents faults. The method involves connecting the battery pack and device with contacts for power, signals, and temperature monitoring.

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Abstract This paper proposes a versatile thermal management solution utilizing phase change material (PCM) for compact 21700 battery modules. First, flame-retardant and heat-conductive pouring sealant is utilized to encapsulate the PCM. The impact of diameter number PCM columns on performance module evaluated by single-factor multi-objective optimization methods. Then, low-temperature heating scheme film heaters devised module. results indicate that heat generation diminishes as working temperature rises, whereas it escalates with an increase in discharge rate. When 8 inner outer heights are 66 mm 13 mm, maximum difference controlled at 45.6 C 4.61 C, respectively. With power 13.6 W, average may from -5 11.7 25 minutes, resulting differential 4.6 C.

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The increasing adoption of electric vehicles (EVs) necessitates advancements in battery management systems (BMS) to enhance safety, performance, and longevity. This comprehensive review explores advanced tools technologies integral modern BMS, emphasising their roles optimising EV efficiency safety. Key areas discussed include the application machine learning algorithms for predictive maintenance, sensor integration accurate system monitoring, thermal solutions mitigate overheating risks. Additionally, highlights innovative use digital twins real-time diagnostics cloud computing expansive data analysis. These collectively improve reliability functionality crucial broader acceptance success market.

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Battery cell assembly with accurate temperature measurement for improved safety and a manufacturing method for it. The assembly uses a thermistor to measure the temperature of the battery cell. The thermistor is mounted on the PCB outside the cell, and a thermally conductive adhesive is added between the thermistor and cell to transfer heat. This allows accurate temperature measurement compared to when the thermistor is isolated. The adhesive bridge enables direct thermal connection between the cell and thermistor.

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Integrated thermal switching and sensing devices for electrical connectors that provide overtemperature protection and monitoring for electrical components like batteries. The devices are integrated inside the connector body and thermally coupled to the component terminals. They have a thermal switching element and a thermal sensor in parallel. When the component temperature exceeds a threshold, the switching element opens and the sensor resistance increases. This signals an overtemperature to an external control device. The switching element prevents further current flow while the sensor provides a temperature alert.

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Method for producing a traction battery for electric vehicles that enables rapid and inexpensive production of the battery while enabling accurate temperature measurement. Each battery cell in the module has a separate temperature sensor. The sensor is mounted on a metal carrier that is welded to the cell housing. This allows direct thermal contact between the sensor and the cell housing for accurate temperature measurement. The connector that electrically connects the cells is also welded in the same step.

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Electric vehicles (EVs) are pivotal in reducing greenhouse gas emissions and achieving sustainable transportation goals. However, lithium-ion batteries (LIBs), the primary energy source for EVs, face critical thermal management, safety, long-term efficiency challenges. This study proposes an integrated battery management system that combines a waterethylene glycol-based liquid cooling mechanism with high-conductivity copper tubing to enhance LIB performance, longevity, safety. Through COMSOL multiphysics simulations, this examines behavior under varying operational conditions. The results indicate 20% reduction temperature peaks, maintaining optimal range of 15C 35C, thus mitigating risks runaway. Experimental validation using infrared thermography imaging confirms system's efficiency, showing maximum recorded 43.48C load conditions, significantly lower than unmanaged systems. Beyond work integrates advanced strategies, including state-of-charge estimation, predictive fault diagnostics, active optimization, cell balancing. analysis further reveals proposed improves heat diss... Read More

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Battery thermal management systems (BTMS) ensure the safety and performance of lithium-ion batteries, which power electric vehicles. However, designing an effective BTMS is challenging due to batteries' complex behaviour sensitivity temperature variations. This review comprehensively explores current vital technologies trends in BTMS, explicitly focusing on analysing various cooling control strategies. To discuss four primary technologies: air cooling, liquid immersion phase change material (PCM) cooling. The advantages disadvantages each technology are compared terms cost-effectiveness, applicability, limitations when dealing with high-energy-density batteries. Furthermore, delves into discussion strategies data prediction methods for emphasizing importance advanced analysis optimising battery safety. Different strategies, such as passive, active, hybrid control, introduced evaluated. Data methods, artificial neural networks, fuzzy logic, machine learning, also presented discussed. comprehensive provides in-depth understanding while serving a valuable reference future research appli... Read More

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Temperature sensor for battery modules in electric vehicles that has a housing made of a specific polymer composition that allows high flow properties and good heat resistance. The polymer composition contains a thermotropic liquid crystalline polymer and has a melt viscosity of 300 Pa-s or less and a deflection temperature under load of 170° C or more. This allows the sensor to have high flowability during molding and processing while also having good short-term heat resistance during operation. The combination of low melt viscosity and high DTUL provides a balance between processability and heat resistance for the temperature sensor housing material.

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System and control methodology for heating and charging battery packs using AC power, enabling rapid and efficient thermal management. The system integrates AC power delivery with a temperature-controlled heating circuit, where the heating element is controlled by a temperature sensor. The charging circuit includes rectifier switches, a transformer, and a series switch. During charging, the charging circuit injects AC current into the battery through the series switch, while the heating circuit injects DC current through a transformer and series switch. This synchronized operation ensures uniform heat distribution across the battery pack.

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Thermal regulation system for vehicle batteries that provides safe and reliable operation of high-power batteries in vehicles. The system uses a closed fluid network with a pump to circulate dielectric heat transfer fluid through the battery modules. Temperature sensors monitor the battery and the fluid. A control unit switches between free circulation, heating, and cooling modes based on sensor readings. This allows precise temperature control of the batteries without relying solely on ambient cooling or active cooling devices.

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A liquid cooling module for vehicles that simplifies the deployment of a temperature sensor to monitor cooling fluid temperature inside the module. The module has a cold plate with a protrusion on one side. The circuit board is attached to the main body of the cold plate using the protrusion as a fastener. The temperature sensor is located on the circuit board adjacent to the protrusion. The sensor is connected to the protrusion using a thermally conductive medium to measure the cooling fluid temperature. This eliminates the need for a separate installation process for the temperature sensor.

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System for controlling battery temperature and power consumption in electric vehicles to avoid battery voltage drop without sacrificing driving range. The system has a temperature sensor, heater, battery controller, and drive controller. When the battery temperature is low but charge is high, the drive controller instructs the battery controller to heat the battery. When the battery temp is low and charge is low, the drive controller limits power consumption. This prevents voltage drop due to increased internal resistance when heating is stopped. By balancing heating and power limits, the system extends battery life without sacrificing range.

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A portable device for testing multiple temperature sensors simultaneously in the field without requiring user intervention to select which sensor to test. The device automatically tests each connected sensor in sequence and provides results for leakage current, functionality, and temperature accuracy. It can detect short circuits, broken sensors, and disconnections. This improves efficiency compared to manually testing one sensor at a time.

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ABSTRACT A ratiometric timedomain temperature sensor is presented in this work. The frontend of the generates two temperaturedependent currents: proportional to absolute (PTAT) and complementary (CTAT), which bias ring oscillators, first PTAT clock second CTAT clock. clocks are combined within an alldigital sigmadelta converter consisting up/down counter, a FlipFlop, 12bit counter. occupies area only 0.019 mm 2 , gives it advantage over vast majority smart sensors 180nm technology, including some lower nodes. min/max accuracies measured 12 parts 0.6/+6.6C achieved with 1point 2.7/+2.3C 2point trimming. nominal resolution 0.3C (effective 0.37C ENOB 8.8 bits) measuring range 40 125C.

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Electric vehicle (xEV) battery durability significantly impacts the long-term operation, consumer satisfaction, and market adoption of xEVs. As driving range diminishes over time, it affects service life lifecycle GHG emissions. Measuring full xEV batteries in laboratory tests presents technical logistical challenges, necessitating representative measurements for parameterizing numerical models. These models are crucial predicting performance rely on high-quality experimental data. While aging trends under extreme temperatures documented, cell thermal contact conditions suitable direct model input not well characterized. This study investigates lithium-ion cells from three types, cycled at constant currents C/40 to 1C, between 15 C +45 C, 1000 cycles a multi-year campaign. Stable isothermal were achieved using custom-built liquid immersion baths with forced convection, highlighting fundamental electrochemical behaviors by decoupling complex self-heating typically monitored air environments. The data inform validate physics-based temperature-dependent durability, providing oper... Read More

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Electrical module and battery pack design for improving voltage and temperature collection accuracy in electric vehicles. The design brings the cell voltage and temperature sensors closer to the module's electrical interface to reduce signal transmission length. This is done by integrating the sensor circuitry into the module instead of using separate sensors and cables. The module has a cells contact system to collect voltages and temperatures, and an on-board cell supervision circuit with analog front ends to convert the signals. This reduces the length of analog signal transmission compared to conventional designs with separate sensors and cables. The closer proximity of the sensors to the module interface reduces transmission path interference and improves voltage and temperature accuracy.

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