Support & Technical Resources
Tools, guides and reference for specifying, installing and maintaining fire detection — a battery calculator, our explainer guides, where to find manuals, and how to reach our engineers. From Midland Fire Direct, a BAFE SP203-1 certified fire detection supplier.
On this page: battery calculator · guides · manuals · quick reference · getting help
Fire alarm battery calculator
Size a fire alarm panel's standby batteries to BS 5839-1:2025 Annex E. Enter the panel's currents and standby period; the tool returns the minimum capacity and the next stocked battery size. For the method, the worked example and the FAQs, see the full fire alarm battery calculator guide.
Enter the panel's figures and press Calculate.
Calculated per BS 5839-1:2025 Annex E: minimum capacity = 1.25 × [(I₁ × T₁) + D × (I₂ × T₂)], where 1.25 is the ageing factor and D is the alarm de-rating — D = 1 where the battery's 20-hour rate (Cmin/20) is at least the alarm current, otherwise D = 1.75 (or the battery manufacturer's figure). A 24 V panel needs two 12 V batteries of the resulting capacity, wired in series. Always confirm against the panel manufacturer's data and the system design.
Fire detection guides
Manuals & documentation
Installation, commissioning and user documentation comes from the manufacturer's official sources — we index where to find it rather than hosting copies, and we supply the relevant documentation with equipment orders. The Gent manuals & documentation hub covers the Nano, Vigilon, conventional Xenex and S-Quad families and links the official Honeywell sources; for software and commissioning tools, see the Gent fire alarm software & commissioning tool page. For other brands — Morley-IAS, Xtralis VESDA and FAAST — or a specific revision, contact us with the model and we will point you to the current document.
Fire detection how-tos
Reducing false alarms
Unwanted alarms — from cooking fumes, steam, dust or a detector sited too close to a source — are the most common fire-alarm nuisance and a frequent reason systems get ignored. Multi-sensor detectors that combine optical smoke and heat sensing, like the Gent S-Quad family, discriminate better between a real fire and everyday activity than single-sensor smoke detectors, and choosing the right detector type for each area — heat rather than smoke in kitchens, for example — cuts false alarms further.
Conventional vs addressable systems
A conventional system divides a building into zones of hard-wired circuits, so the panel reports "a device in zone 3". An addressable system gives every device its own identity on a loop, so the panel names the exact detector or call point. Conventional suits small, simple buildings; addressable suits larger, networked or phased sites where finding a fault quickly matters. See conventional systems and the addressable Gent by Honeywell and Morley-IAS ranges — or the BS 5839 categories guide for how the specification drives the choice.
Detector families and what each senses
Fire detectors sense different things: optical smoke detectors for smouldering fires, heat detectors for hot, fast-developing fires or dirtier environments, multi-sensor detectors that combine both, flame detectors for the radiant energy of a flame in high-risk industrial areas, and aspirating systems that draw air to a central sensor. The right mix depends on the fire risk and conditions in each area of the building.
Fire alarm terms, in plain English
A few terms that come up constantly: a manual call point (MCP) is the "break-glass" unit that triggers the alarm by hand; a VAD is a visual alarm device (a beacon) for where sounders alone aren't enough; a loop is the wiring circuit an addressable panel runs devices on, a zone the area a conventional circuit covers; quiescent current is the draw in normal operation and alarm current the draw with everything sounding — the two figures the battery calculator needs; and a VRLA battery is the sealed lead-acid standby battery a panel uses.
Aspirating smoke detection (ASD) basics
Aspirating smoke detection draws air from the protected space through a network of pipes to a central, highly sensitive detector, giving very early warning before smoke is visible. It suits high-value, high-airflow or hard-to-access spaces — data centres, warehouses, cold stores and heritage buildings — where spot detectors would respond too late or be difficult to reach for maintenance. See Xtralis VESDA and Honeywell FAAST.
Lithium-ion off-gas detection
Lithium-ion batteries vent gas before they reach thermal runaway. Off-gas detection senses those early gases — ahead of smoke or heat — to give warning in battery stores, EV charging areas and battery energy-storage systems, where a conventional fire detector would react too late. Li-ion Tamer is the specialist off-gas system we supply for this.
Getting technical help
Most of our customers are fire alarm engineers and maintenance companies, and our team answers product and specification questions on the phone every day. Call 0844 997 0001, use the contact form, or request a quote. To get a useful answer fastest, have the panel make and model to hand, and for battery sizing the quiescent and alarm currents from the panel data.
Running an older Gent estate? We hold legacy Gent spares and can advise on like-for-like replacements — call with the panel model and part number. And where the job needs design, installation, commissioning or a maintenance contract rather than supply, our services team covers that too.
Tell us the panel — we'll do the rest.
Send the panel model or the part numbers and we'll match the equipment and quote the stocked items same-day.