480.10 Battery Locations
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.