Article 480 Storage Batteries
Informational Note: The following standards are frequently referenced for the installation of stationary batteries:
- IEEE 484, Recommended Practice for Installation Design and Installation of Vented Lead-Acid Batteries for Stationary Applications
- IEEE 485, Recommended Practice for Sizing Vented Lead-Acid Storage Batteries for Stationary Applications
- IEEE 1145, Recommended Practice for Installation and Maintenance of Nickel-Cadmium Batteries for Photovoltaic (PV) Systems
- IEEE 1187, Recommended Practice for Installation Design, and Installation of Valve-Regulated Lead-Acid Batteries for Stationary Applications
- IEEE 1375, IEEE Guide for the Protection of Stationary Battery Systems
- IEEE 1578, Recommended Practice for Stationary Battery Electrolyte Spill Containment and Management
- IEEE 1635/ASHRAE 21, Guide for the Ventilation and Thermal Management of Batteries for Stationary Applications
- UL. 1973, Standard for Batteries for Use in Stationary, Vehicle Auxiliary Power, and Light Electric Rail (LER) Applications
- UL. Subject 2436, Outline of Investigation for Spill Containment for Stationary Lead Acid Battery Systems
- UL 1989, Standard for Standby Batteries
- UL Subject 1974, Standard for Evaluation of Repurposed Batteries
Cell. The basic electrochemical unit, characterized by an anode and a cathode, used to receive, store, and deliver electrical energy.
Nominal Voltage (Battery or Cell). The value assigned to a cell or battery of a given voltage class for the purpose of convenient designation. The operating voltage of the cell or battery may vary above or below this value.
Informational Note: The most common nominal cell voltages are 2 volts per cell for the lead-acid systems, 1.2 volts per cell for alkali systems, and 3.6 to 3.8 volts per cell for Li-ion systems. Nominal voltages might vary with different chemistries.
Sealed Cell or Battery. A cell or battery that has no provision for the routine addition of water or electrolyte or for external measurement of electrolyte specific gravity and might contain pressure relief venting.
Storage Battery (Battery). A single or group of rechargeable cells connected together electrically in series, in parallel, or a combination of both, and comprised of lead-acid, nickel-cadmium, or other rechargeable electrochemical types.
Informational Note: The battery manufacturer's installation and instruction manual can be used for guidance for acceptable materials.
Informational Note: Conductors sized to prevent a voltage drop exceeding 3 percent of maximum anticipated load, and where the maximum total voltage drop to the furthest point of connection does not exceed 5 percent, may not be appropriate for all battery applications. IEEE 1375—2003, Guide for the Protection of Stationary Battery Systems, provides guidance for overcurrent protection and associated cable sizing.
Informational Note: Conductors are commonly pre-formed to eliminate stress on battery terminations. Fine stranded cables may also eliminate the stress on battery terminations. See the manufacturer's instructions for guidance.
(3) An arc flash label in accordance with acceptable industry practice
Informational Note: NFPA 70E-2018, Standard for Electrical Safety in the Workplace, provides assistance in determining the severity of potential exposure, planning safe work practices, arc flash labeling, and selecting personal protective equipment.
(4) Date the calculation was performed
Exception: List items (2), (3), and (4) shall not apply to one-and two-family dwellings.
Informational Note No. 1: See NFPA 1—2018, Fire Code, Chapter 52, for ventilation considerations for specific battery chemistries.
Informational Note No. 2: Some battery technologies do not require ventilation.
Informational Note No. 3: For additional information on the ventilation of stationary battery systems, see IEEE Std 1635—2012/ASHRAE Guideline 21—2012 Guide for the Ventilation and Thermal Management of Batteries for Stationary Applications.
For battery racks, there shall be a minimum clearance of 25 mm (1 in.) between a cell container and any wall or structure on the side not requiring access for maintenance. Battery stands shall be permitted to contact adjacent walls or structures, provided that the battery shelf has a free air space for not less than 90 percent of its length.
Informational Note: Additional space is often needed to accommodate battery hoisting equipment, tray removal, or spill containment.
Informational Note: IEEE 1187—2013, IEEE Recommended Practice for Installation Design and Installation of Valve-Regulated Lead-Acid Batteries for Stationary Applications, provides guidance for top clearance of valve-regulated lead-acid batteries, which are commonly used in battery cabinets.