A graded intruder alarm is only as certifiable as its evidence trail. The panel carries the EN 50131 series declaration, but that declaration rests on a stack of lower-level proof - the power-supply clauses of EN 50131-6, the cell-performance methods of IEC 61951-2, the sealed-cell safety requirements of IEC 62133-1, and the transport evidence that lets the finished product ship by air and road. Paper C assembles that stack, explains how each test is run and what it proves, and shows how a NiMH pack supplier can front-load the documentation so the panel's own certification is a matter of assembly rather than rediscovery.
The evidence trail begins at system level with EN 50131-1, which defines the four security grades and four environmental classes and states the functional expectations to which every subsystem - including power - must conform. A manufacturer first fixes the intended grade (most commercial systems are Grade 2; higher-risk sites Grade 3) and environmental class (typically Class II indoor general). Those two choices determine almost everything downstream: the standby hours, the temperature range over which they must be delivered, and the depth of fault and tamper supervision the power subsystem must support.
The animated evidence stack shows how the system standard sits above the dedicated power-supply standard, which in turn sits above the cell-level standards. Skipping a layer - quoting a cell datasheet against a system-grade requirement, for example - is a common certification gap, because the tests operate at different levels and prove different things.
EN 50131-6:2017 is the dedicated power-supply standard and the heart of the battery evidence. Its tests include the graded standby-duration test, in which the supply, with a battery charged per the manufacturer's method, is disconnected from the mains and required to sustain the declared normal (and, where specified, alarm) load for the grade's minimum - 12 hours for Grade 1 and 2 Type A, 24 hours for Grade 3 and 4 and for Type B. It includes the changeover test, which verifies that switching between mains and battery and back raises no alarm, tamper or fault. It includes the recharge test, requiring return to 80 percent within 72 hours, and a series of output-voltage, fault and supervision tests.
For the battery supplier this means the pack must be characterised not just for nominal capacity but for delivered capacity at the standby current and across the declared temperature range, with a documented end-of-life margin. A pack that meets the standby duration only when new and cold does not support a robust grade declaration.
Below the system standard sits the cell-performance standard for portable sealed rechargeable nickel-metal hydride cells and batteries, IEC 61951-2. It defines the standard charge and discharge methods, the 20-degree-C reference capacity test, charge retention after storage, endurance - a reference minimum of 500 cycles under its prescribed regime - overcharge behaviour and long-term or permanent charge behaviour. These methods give the panel manufacturer a common, defensible language for what the cell will do, rather than relying on a supplier's bespoke figures.
The animated fade curve illustrates why endurance and charge-retention data matter in a standby product: a pack held at readiness loses usable capacity gradually, and faster in a warm enclosure. IEC 61951-2 supplies the controlled test conditions; the designer applies the derating that maps those conditions onto the panel's real, warmer life. The curve is illustrative, but the standard behind it is not - it is the reference a notified body recognises.
Safety for sealed nickel cells is governed by IEC 62133-1 (the nickel half of the IEC 62133 pair; lithium is Part 2), with the current edition consolidating requirements for operation under intended use and reasonably foreseeable misuse. Its test programme covers continuous low-rate charging, external short circuit, forced discharge and the mechanical and thermal abuse cases appropriate to the chemistry. Passing IEC 62133-1 is the evidence that the cell will not vent dangerously or ignite under the fault conditions a panel enclosure can realistically present.
This is a genuine advantage for aqueous NiMH over lithium in a safety-grade product: the abuse envelope is forgiving, the failure mode tends to vent rather than propagate thermal runaway, and no lithium-specific protection PCB is required to achieve a safe cell. The pack still needs sensible fusing and insulation, but the safety case is simpler and well understood by test houses.
Before the product reaches an installer it must ship. Sealed NiMH cells and packs travel under the UN Manual of Tests and Criteria Section 38.3 (UN 38.3) test summary regime, and under the IATA/ICAO and ADR rules nickel-metal hydride is classified as not subject to the lithium-battery restrictions: properly packaged NiMH is not regulated as a dangerous good in the way lithium is, which materially simplifies air freight and small-parcel logistics. A supplier that provides the UN 38.3 test summary and a chemistry declaration removes a recurring shipping bottleneck.
National application standards add the final overlay. In the UK, PD 6662 maps the EN 50131 series onto British installation practice and police-response policy, while DD CLC/TS 50131-7 gives application guidance; other countries add their own annexes. These do not change the cell, but they can change the stated standby scenario - which is why the pack's capacity margin, established in Paper B, has to absorb national variations without redesign.
The practical payoff is a documentation pack assembled once and reused across panel variants: IEC 61951-2 capacity and endurance reports establishing the cell's performance baseline; IEC 62133-1 safety reports establishing the abuse envelope; UN 38.3 summaries and chemistry declarations for shipping; matched-lot and internal-resistance records for the welded pack; and a delivered-capacity curve at the panel's standby current and temperature range that lets the EN 50131-6 standby and changeover tests be predicted before they are run. With that stack in place the panel's graded declaration rests on traceable evidence, the annual maintenance test becomes a confirmation rather than a gamble, and the insurer or notified-body review proceeds without surprises.
Together, Papers A through C move from the electrical duty, through the sizing and chemistry decision, to this certifiable evidence trail - the complete engineering case for a NiMH standby pack in an intruder alarm control panel.
Weijiang Power supplies certified NiMH standby packs and the documentation behind them: IEC 61951-2 capacity and endurance reports, IEC 62133-1 sealed-nickel safety evidence, UN 38.3 test summaries and not-subject-to-lithium-restrictions shipping declarations, matched-lot pack records and delivered-capacity curves at your standby current. Tell us your target EN 50131 grade and environmental class and we will assemble the cell-level evidence your panel declaration needs.
