Thermal characteristics of selected EV and HEV batteries

Abstract

Battery management is essential for achieving desired performance and life cycle from a particular battery pack in Electric and Hybrid Vehicles (EV and HEV). The batteries must be thermally managed in addition to the electrical control. In order to design battery pack management systems, the designers need to know the thermal characteristics of modules and batteries. Thermal characteristics that are needed include heat capacity of modules, temperature distribution and heat generation from modules under various charge/discharge profiles. In the last few years, we have been investigating thermal management of batteries and conducting tests to obtain thermal characteristics of various EV and HEV batteries. We used a calorimeter to measure heat capacity and heat generation from batteries and infrared equipment to obtain thermal images of battery modules under load. In this paper, we will present our approach for thermal characterization of batteries (heat generation, heat capacity, and thermal images) by providing selected data on valve regulated lead acid, lithium ion, and nickel zinc battery moduledcells. For each battery type, the heat generation rate depends on the initial state of charge, initial temperature, and charge/discharge profile. Thermal imaging indicated that the temperature distribution in modules/cells depends on their design.

Towards an Ultimate Battery Thermal Management System: A Review

“…It is therefore inevitable that BTMS is typically associated with the process of retaining the operational temperature at an optimal level through keeping the temperature gradient within a relatively narrow range [48]. The BTMS must be designed to suit automotive criteria, which include [49,50]: being lightweight, easily packaged in the desired application-for example, EVs-and they must be compact, reliable, cost-effective, easy to assembly and placed in an appropriate position [51][52][53].…”

Mechatronics design and experimental verification of an electric-vehicle-based hybrid thermal management system

“…The thermal dynamics of a battery as well as cooling systems for EVs and HEVs were modeled in Pesaran and Keyser. 5 Various types of TMSs were examined to control overheated conditions inherent at high power outputs. Ye et al 6 proposed that thermal management effectively enhances the battery discharge efficiency and extends the battery life cycle.…”

An Examination of Thermal Features’ Relevance in the Task of Battery-Fault Detection

“…When the cell is damaged, overloaded or overcharged, it generates additional heat [4], which underlines the importance of temperature monitoring included as a part of the modern BMS. Temperature sensors must be placed directly on the cell surface, or inside the cell itself for proper functioning.…”

“…However, there are other types of sensors, developed especially for BMS purposes. Semiconductor CMOS sensors can provide high accuracy and linearity [4]. Flexible micro temperature sensors can be fabricated into the cells to provide high accuracy measurement with a short response time [5].…”

“…An infrared thermography, such as in studies of the thermal characteristics acquisitions [4] and factory diagnostics [5], was applied mostly for onsite inspections. Such an estimation of a battery condition according to its temperature leads to the overall difficulty and cost decrease while the performance remains the same or at least comparable.…”