IEC 63115-2-2021 pdf Secondary cells and batteries containing alkaline or other non-acid electrolytes – Sealed nickel-metal hydride cells and batteries for use in industrial applications – Part 2: Safety

5 General safety considerations General 5.1 The safety of sealed nickel-metal hydride cells or batteries requires the consideration of two sets of applied conditions: a) intended use; b) reasonably foreseeable misuse. The manufacturer can use “cell block(s) or monobloc(s)” instead of “cell(s)” for any test that specifies “cell(s)”. The manufacturer can use “battery pack” instead of “battery” as the test unit in this document. The cell manufacturer shall clearly declare the test unit for each test. Cells or batteries shall be so designed and constructed that they are safe under conditions of both intended use and reasonably foreseeable misuse. It may also be expected that cells or batteries subjected to intended use shall not only be safe but shall continue to be functional in all respects. It is expected that cells or batteries subjected to misuse may fail to function. However, even if such a situation occurs, they shall not present any significant hazards.
5.5 Terminal connectors The size and shape of the terminal connectors shall be such to ensure that they can carry the maximum anticipated current. External terminal contact surfaces shall be formed from conductive materials with good mechanical strength and corrosion resistance (see appropriate corrosion tests, e.g. IEC 60068-2-60 and IEC 60068-2-11). Terminal connectors shall be arranged so as to minimize the risk of short circuits. Terminal connectors shall be marked to indicate polarity. 5.6 Assembly of cells into batteries If there is more than one battery housed in a single battery enclosure, cells used in the assembly of each battery shall be of the same design, be of the same chemistry and be from the same manufacturer. Manufacturers of cells shall specify current, voltage and temperature limits so that the battery manufacturer and/or designer may ensure proper design and assembly. Batteries that are designed for the selective discharge of a portion of their series connected cells shall incorporate circuitry to prevent operation of cells outside the limits specified by the cell manufacturer. 5.7 Quality plan The manufacturer shall prepare and implement a quality plan that defines procedures for the inspection of materials, components, cells and batteries and which covers the whole process of producing each type of cell or battery. Manufacturers should understand their process capabilities and should institute the necessary process controls as they relate to product safety. 5.8 Type test conditions A battery system that is used outside of its operating region may exhibit hazards originating from the cells or batteries. Such risks shall be taken into consideration in order to prepare a safe test plan. The test facility should have a sufficient structural integrity and a fire suppression system to contain the conditions of overpressure and fire that may occur as a result of testing. The facility should have a ventilation system to dilute gas which might be produced during the tests.