According to NFPA 855, individual energy storage system units should generally be separated by at least three feet, unless the manufacturer has conducted large-scale fire testing (part of UL 9540A) to prove a smaller distance is safe. This prevents a fault in one unit from spreading. • The distance&32;between battery containers&32;should be 3 meters (long side) and 4 meters (short side). If a firewall is installed,&32;the short side distance can be reduced to 0. Our firm concurs that maintaining an aisle not only facilitates access but also. Battery Energy Storage Systems, or BESS, help stabilize electrical grids by providing steady power flow despite fluctuations from inconsistent generation of renewable energy sources and other disruptions. Someone must still work on or maintain the battery system. An exception dictates that where live parts are not accessible during routine ESS maintenance,voltage exceeding 100 volts is.