NFPA 110’s 2025 edition opens the door to reliability-centered maintenance—and new starting-battery chemistries.

Emergency and standby power is a facilities problem before it is a brochure problem. When utility power fails, the generator, transfer switch, starting batteries, and fuel system either perform—or they don’t. NFPA 110, Standard for Emergency and Standby Power Systems, is the performance baseline many Authorities Having Jurisdiction (AHJs) and owners still treat as the reference for those systems. The current edition is 2025.

Confirmed from NFPA and industry briefings that quote the 2025 text: the edition expressly permits reliability-centered maintenance (RCM). Section 8.1.3 states that reliability-centered maintenance shall be permitted. The standard defines RCM as a structured framework for choosing the mix of maintenance activities that sustains operational reliability while keeping operation and support safe and economical. NFPA’s own product page for the 2025 edition lists RCM and new annex material on RCM program adoption among the headline updates. That is permission for a risk-based maintenance strategy—not a blank check to drop required performance outcomes. Annex language used in industry briefings warns that RCM should not jeopardize the maintenance objective that underpins Level 1 and Level 2 EPSS readiness.

The same edition widens allowed starting-battery chemistries. Where the 2022 text limited starting batteries to nickel-cadmium or lead-acid, the 2025 text (5.6.4.5) allows nickel-cadmium, lead-acid, nickel-zinc, lithium-ion, or other stored-energy technology capable of providing sufficient established prime-mover cranking cycles. Maintenance language in 8.3.6 also separates maintainable batteries (electrolyte access) from non-maintainable batteries, and specifies monthly testing methods for non-maintainable units—conductance, ohmic, carbon-pile load, or cranking-voltage-drop testing—alongside weekly inspection expectations for Level 1 starting and control batteries.

Fuel-tank sizing also changed for longer-class systems. For classifications of 24 hours or less, the main fuel tank still needs a minimum capacity of at least 133 percent of the low-fuel sensor quantity. For classifications greater than 24 hours, the 2025 text sets that floor at 100 percent of the low-fuel sensor quantity—where the 2022 edition had required 133 percent across the board. Facility teams should treat that as a design and documentation change to verify against the adopted edition and the AHJ, not as a reason to run tanks dry.

FRG operational interpretation (not a legal or compliance finding): If you own or operate generators that support life-safety, mission-critical, or lease-critical loads, the useful move is a gap check—not a slogan. Confirm which edition your jurisdiction has adopted. Ask whether your maintenance program is still purely calendar-based or whether an RCM framework has been written down, approved, and tied back to the failure modes that actually kill starts. Inventory starting-battery chemistry and match the monthly test method to maintainable versus non-maintainable construction. Re-check fuel-tank capacity against class and the low-fuel sensor setpoint. None of that replaces the full NFPA 110 text, manufacturer instructions, or AHJ direction.

When a facility is preparing for exit, consolidation, or critical-power refresh, those same records—maintenance strategy, battery test evidence, and fuel capacity basis—travel with the asset story. That is where schedule risk and residual value meet.

If you are planning a generator assessment, critical-power refresh, or facility exit that includes gray-space plant, discuss the project with Facility Recovery Group and bring the current maintenance and fuel records to the first call.