Batteries

The special risks associated with conducting crash tests on E-Vehicles can be divided into two main categories; 1) thermal activity inside the battery (resulting from electrical or mechanical abuse) may lead to energetic emission of harmful and/or flammable gases, thermal runaway, and potentially fire, and 2) the risk of electrocution. Procedures to ensure protection from all types of risk must be integrated into the entire crash test process. This informational report is intended to provide guidance in this endeavor using current best practices at the time of this publication. As both battery technology and battery management system technology is in a phase of expansion, the contents of this report must then be gaged against current technology of the time, and updated periodically to retain its applicability and usefulness.
The scope of this document is to provide an understanding of the risks and an overview of the techniques established to reduce the likelihood that an event would cause harm to laboratory personnel and/or property. A laboratory considering E-Vehicle crash testing should work closely with the E-Vehicle manufacturer to identify and understand the risks associated with shipping and handling of their vehicle (pre and post-crash), storage of the vehicle (pre and post-crash), battery system diagnostics procedures, and operation of the vehicle.

This document applies to a Plug-in Electric Vehicle (PEV) which is equipped with an onboard inverter and communicates using the Smart Energy Profile 2.0 Application Protocol (SEP2). It is a supplement to the SEP2 Standard, which supports the use cases defined by J2836/3™. It provides guidance for the use of the SEP2 Distributed Energy Resource Function Set with a PEV. It also provides guidance for the use of the SEP2 Flow Reservation Function Set, when used for discharging. It is not intended to be a comprehensive guide to the use of SEP2 in a PEV.

This document describes a test procedure for rating peak power of the Rechargeable Energy Storage System (RESS) used in a combustion engine Hybrid Electric Vehicle (HEV). Other types of vehicles with non fossil fuel primary engines, such as fuel cells, are not intended to use this test procedure.

This SAE Recommended Practice describes the vibration durability testing of a single battery (test unit) consisting of either an electric vehicle battery module or an electric vehicle battery pack. For statistical purposes, multiple samples would normally be subjected to such testing. Additionally, some test units may be subjected to life cycle testing (either after or during vibration testing) to determine the effects of vibration on battery life. Such life testing is not described in this procedure; SAE J2288 may be used for this purpose as applicable. Finally, impact testing, such as crash and pothole, is not included in this procedure.

This SAE Recommended Practice defines a standardized test method to determine the expected service life, in cycles, of electric vehicle battery modules. It is based on a set of nominal or baseline operating conditions in order to characterize the expected degradation in electrical performance as a function of life and to identify relevant failure mechanisms where possible. Accelerated aging is not included in the scope of this procedure, although the time compression resulting from continuous testing may unintentionally accelerate battery degradation unless test conditions are carefully controlled. The process used to define a test matrix of accelerated aging conditions based on failure mechanisms, and to establish statistical confidence levels for the results, is considered beyond the scope of this document.
Because the intent is to use standard testing conditions whenever possible, results from the evaluation of different technologies should be comparable. End-of-life is determined based on module capacity and power ratings. This may result in a measured cycle life different than that which would be determined based on actual capacity; however, this approach permits a battery manufacturer to make necessary tradeoffs between power and energy in establishing ratings for a battery module. This approach is considered appropriate for a mature design or production battery. It should be noted that the procedure defined in this document is functionally identical to the USABC Baseline Life Cycle Test Procedure.

This SAE Recommended Practice provides for common test and verification methods to determine Electric Vehicle battery module performance. The document creates the necessary performance standards to determine (a) what the basic performance of EV battery modules is; and (b) whether battery modules meet minimum performance specification established by vehicle manufacturers or other purchasers. Specific values for these minimum performance specifications are not a part of this document.

This SAE Recommended Practice provides for common battery designs through the description of dimensions, termination, retention, venting system, and other features required in an electric vehicle application. The document does not provide for performance standards. Performance will be addressed by SAE J1798. This document does provide for guidelines in proper packaging of battery modules to meet performance criteria detailed in J1766.

This SAE Information Report contains definitions for HEV and EV terminology. It is intended that this document be a resource for those writing other HEV and EV documents, specifications, standards, or recommended practices.

Recommended information for an objective evaluation of an emerging or alternative energy storage device or system by a potential user for any stationary application is covered in this document. Energy storage technologies are those that provide a means for the reversible storage of electrical energy, i.e., the device receives electrical energy and is able to discharge electrical energy at a later time. The storage medium may be electrochemical (e.g., batteries), kinetic (e.g., flywheels), electrostatic (e.g., electric double-layer capacitors), thermal, compressed air, or some other medium. Devices recharged by non-electrical means, such as fuel cells, are beyond the scope of this document. The document provides a common basis for the expression of performance characteristics and the treatment of life-testing data. A standard approach for analysis of failure modes is also provided, including assessment of safety attributes. The intent of this document is to ensure that characterization information, including test conditions and limits of applicability, is sufficiently complete to allow valid comparisons to be made.

Various battery systems are discussed so that the user can make informed decisions on selection, installation design, installation, maintenance, and testing of stationary standby batteries used in uninterruptible power supply (UPS) systems. This guide describes how the UPS battery charging and converter components can relate to the selection of the battery systems. Design requirements of the UPS components are beyond the scope of this document. Battery back-up systems for dc-output rectifiers are also beyond the scope of this document.