Because the fire-panel battery exists to protect life, its evidence trail is the most demanding in the backup family: a type-tested control standard, a dedicated power-supply standard with quantitative standby and recharge tests, a system-compatibility standard, national application and US counterparts, and the cell-level performance and safety documents beneath them all. Paper C assembles that stack for a nickel-metal hydride pack, explains what each test proves, and shows how a supplier can front-load the documentation so a panel's EN 54 (or UL 864) declaration rests on traceable, test-house-recognised evidence.
EN 54-2 is the type-test standard for the fire control and indicating equipment. Its requirements frame everything the power supply must support: a fire signal indicated within ten seconds; operation under single-fault conditions, including an earth fault or a short circuit on one part, without losing the ability to report other zones; mandatory functions and a defined set of optional functions whose presence is declared; and unambiguous indication of alarm, fault and disablement states. The battery is tested indirectly but relentlessly here, because every one of these functions must continue when the PSE is running on its standby source.
For the pack supplier this means the cells must deliver a rail stable enough that single-fault resilience, rapid alarm indication and zone isolation all behave identically on battery as on mains - which returns to the low-impedance, flat-plateau characteristics established in Papers A and B.
EN 54-4 is the battery's own standard and carries the quantitative heart of the evidence. Its type tests include the standby-and-alarm duration test, in which the PSE, fed by its battery after mains removal, must sustain the quiescent load for the declared period - 24 hours, or 72 where required - followed by the full alarm load for at least 30 minutes. They include the recharge test (80 percent within 24 hours, full within a further 48), output-voltage and ripple tests, battery-presence and fault supervision tests, and environmental tests over the declared range. Passing these is what allows the CE mark under the construction-products regulation for the PSE component.
The NiMH supplier supports these tests with delivered-capacity data at the actual quiescent and alarm currents and across the temperature range, so the duration test result is predictable. The pack's end-of-life margin - established through the Annex E calculation - ensures the type-test result does not erode below the requirement during service.
A fire system is more than its panel, and EN 54-13 addresses system compatibility: when components from different sources are combined, the assembled system must still meet its requirements, which includes the power supply's ability to carry the real, fully loaded configuration - every detector, module and notification appliance the installed system actually contains, not only the panel in isolation. EN 54-14 provides planning, design, commissioning and maintenance guidance, and national standards such as BS 5839-1 (with its Annex E battery calculation in the current edition) translate the European requirements into UK installation practice, including the 24- versus 72-hour standby decision based on monitoring and occupancy.
This layer is why the battery must be sized to the installed load schedule: a PSE that passes EN 54-4 with a nominal load can still under-serve a densely populated system unless EN 54-13 compatibility and the Annex E sum are applied to the real device list.
For products sold into North America the parallel frame is UL 864, the standard for control units and accessories for fire-alarm systems, read with the NFPA 72 national fire-alarm and signalling code. UL 864 imposes its own standby and alarm duration requirements - historically 24 hours standby plus five or fifteen minutes of alarm depending on configuration, with 60 hours for certain monitored/non-monitored cases - along with battery-charging, supervision and single-fault provisions that mirror the European logic in substance while differing in detail. A pack designed to the more demanding 24-plus-30 EN 54-4 envelope, with documented capacity and a stable rail, is well placed to satisfy the UL 864 duration and supervision tests as well.
Supplying a single NiMH pack family with the capacity and evidence to clear both EN 54-4 and UL 864 simplifies dual-certification product lines and avoids maintaining separate battery designs for adjacent markets.
Beneath the fire standards sit the cell documents. IEC 61951-2 provides the standard charge/discharge methods, charge retention and the reference endurance of at least 500 cycles, framing the pack's capacity and float-life claims; the animated fade curve illustrates how capacity declines under continuous float, faster in a warm enclosure - the quantity the end-of-life derating protects. IEC 62133-1 establishes sealed-nickel safety under charging, short circuit, forced discharge and mechanical/thermal abuse, with NiMH's venting, non-propagating failure mode well matched to a life-safety enclosure. UN 38.3 summaries and a nickel-chemistry declaration then clear transport, and NiMH is not subject to lithium-battery restrictions - a genuine advantage for urgent replacement-pack shipments to fire-system service companies.
Together these give the panel maker performance-characterised, safety-proven, shippable cells rather than generic components whose evidence would otherwise have to be reconstructed at type-test time.
Assembled in order, the evidence closes completely: EN 54-2 fixes the resilient functions the supply must maintain; EN 54-4 type-tests the 24/72-hour standby plus 30-minute alarm duty and the recharge windows; EN 54-13 confirms the fully loaded system is compatible; BS 5839-1 Annex E and UL 864/NFPA 72 cover national application and the US market; IEC 61951-2 characterises the cell; IEC 62133-1 proves its safety; and UN 38.3 clears it for freight. A NiMH supplier that provides matched-lot records, delivered-capacity curves at the real loads and this documentation stack lets a fire-panel manufacturer declare, certify and maintain a life-safety backup with no evidentiary gaps.
Papers A through C complete the engineering case - duty, sizing and certification - for nickel-metal hydride in the fire alarm control panel, where the battery's quiet 24-hour watch and decisive 30-minute alarm are, quite literally, the difference between an orderly evacuation and silence.
Weijiang Power supplies certified 24 V NiMH packs for fire-alarm panel and PSE manufacturers: IEC 61951-2 capacity, endurance and charge-retention reports, delivered-capacity curves at your quiescent and alarm currents, IEC 62133-1 sealed-nickel safety evidence, UN 38.3 summaries and nickel-chemistry shipping declarations, sized to EN 54-4 and aligned with BS 5839 Annex E and UL 864. Send your load schedule and target markets and we will assemble the life-safety evidence file.
