Battery Backup Emergency Lighting Buyers Guide

Quick Picks

Overview

Battery backup emergency lights (often called “unit equipment”) are standalone fixtures with integrated batteries. During normal power, they charge and stay on standby. When the power does fail, they automatically take over—keeping halls, stairs, and exit paths lit for at least 90 minutes.

Big picture: emergency lights are required by national building and fire codes in all commercial facilities (UL 924, NFPA 101, OSHA). They must activate on loss of power, provide enough illumination for safe egress, and last the full runtime. You’ll find them in office buildings, schools, retail centers—nearly every place the public or employees may need to exit in the dark.

Why It’s Required

Building codes make emergency lighting mandatory for most occupied spaces. The Life Safety Code (NFPA 101) and OSHA regulations require a reliable, 90-minute emergency light source for all commercial, industrial, and institutional buildings. That’s why unit equipment is ubiquitous: it’s a simple, cost-effective way to meet these rules and keep occupants safe.

• Code references: Key passages include NFPA 101 7.9 (Emergency Lighting Requirements), OSHA 1910.37 (Exit Routes), and NEC 700 (Emergency Systems).
• Coverage: Lights must illuminate all aisles, corridors, stairwells, and exits—to at least 1 foot-candle minimum, 0.1 fc minimum at floor (per NFPA 101).
• Activation: Units must sense loss of normal power and switch on automatically (typically under 1 second).

AHJ tip: Your local Authority Having Jurisdiction (fire marshal or building inspector) enforces these requirements. Always confirm any additional state or municipal rules (e.g., NYC and Chicago codes) during design.

Key Buying Features

To pick the right unit, focus on the features that drive real-world performance, reliability, and inspection success:

• Lamp brightness: higher output (measured in lumens) covers more floor area or larger rooms. LED optics vary from wide flood to narrow spot—choose based on ceiling height and spacing.
• Battery type: Sealed lead-acid (SLA) batteries are common and low-cost, but modern lithium iron phosphate (LiFePO₄) packs offer longer life and quicker recharge.
• Housing durability: thermoplastic (plastic) units are lightweight and budget-friendly, while steel or die-cast housings resist abuse and heat (often required in stairwells or industrial areas).
• Environment rating: if installing outdoors or in wet locations, look for NEMA-rated, gasketed housings. Cold-weather models include heaters for freezing temps.

Note: All UL 924 lights will provide the baseline 90 minutes of emergency runtime. The differentiators are how much area they illuminate (brightness), how robust they are (construction), and how they ease upkeep (self-testing, faster recharge, etc.).

Battery Runtime, Voltage & Wattage (Made Simple)

A standard emergency light runs for ≥ 90 minutes on battery. How far that gets you depends on:

• Battery capacity (Wattage): Batteries are sized by watts (or volt-amps) for 90 minutes. E.g., a 18 W unit can support 12 W of lamps for 90 min (12 W × 1.5 h = 18 Wh). Exceed that load, and runtime drops.
• Lamp load (Wattage): Each lamp head draws a certain wattage. Two 5.4 W LED heads = 10.8 W load. An 18 W unit handles that easily; a 12 W unit would fall short of 90 min.
• Circuit voltage: Most units accept 120 V or 277 V AC (auto-sensing). This is separate from battery output, which is low-voltage (often 6 V, 12 V, or similar DC to the lamps).

Rule of thumb: Always leave at least a 10–20% wattage buffer when sizing battery units. That covers LED manufacturing tolerances, cold temperatures (which reduce battery output), and aging (capacity loss over time).

Top Use Cases

Battery units are versatile and found in almost every building type. A few scenarios and tips:

• Office & Retail: compact, low-profile units blend into ceilings and walls. Place at 50-foot intervals in halls.
• Warehouses: high-output units with MR16 lamps can reach tall ceilings and wide open areas—spaced far apart.
• Schools & Hospitals: self-testing models minimize time spent on required monthly and annual checks.
• Apartments & Hotels: use decorative or recessed units in lobbies and corridors to maintain aesthetics.

Outdoor note: Choose wet-location units for any area exposed to the elements (rain, snow, humidity). NEMA 3R/4X enclosures and gasketed seals are a must for reliable operation outside.

Installation Best Practices

• Mounting height: Typically 7–10 feet above floor for optimal light spread. Don’t mount so high that light won’t reach the egress path.
• Circuit type: Connect to an unswitched power source (so it’s always charging). If on a switch, use a listed emergency transfer device.
• Branch identification: Per NEC, mark circuits and breakers supplying emergency lights as “Emergency” for clarity.

Pro tip: Always perform a push-button test after installation to verify the lamps and charging circuit work properly. Adjust the lamp heads to eliminate any dark spots along the egress route.

Maintenance Tips

• Monthly: Press the test button for ~30 seconds—confirm lamps light and status LED is normal.
• Annually: Perform a full 90-minute discharge test building-wide; replace weak batteries.
• Watch Indicators: Self-test models blink or change color to flag faults—don’t ignore them.

Battery care: Most batteries last 3–5 years. Replace them proactively if runtime falls short. In high-temperature areas, consider heat-resistant models or remote battery cabinets to prolong life.

Featured Emergency Lights

Solid, proven picks to cover common scenarios:

E-1 Series Compact LED Emergency Light

Ultra-compact, budget-friendly, and easy to mount. Twin adjustable LED heads, dual-voltage (120/277 V), and a Ni-Cd battery for the 90-minute baseline. Great for corridors, offices, and utility rooms.

CAEM Steel Emergency Light – Chicago Approved

Rugged steel housing for tougher environments and jurisdictions that require metal (e.g., Chicago). High-output LED heads, sealed lead-acid battery, and dependable ≥ 90-minute performance.

HPEM High-Performance Emergency Light

High-lumen MR16 heads for longer spacing in big rooms. Efficient LiFePO₄ battery delivers long life and fast recharge. Optional self-diagnostics simplifies testing.

RMR-16-WP Wet-Location Emergency Unit

Weather-resistant, gasketed construction with LED MR16 heads for exterior doors, covered walkways, and loading docks. Cold-weather options available.

FRM Recessed Emergency Light

Architectural look: the fixture hides in the ceiling and deploys pop-out LEDs during outages. Ideal for lobbies and finished spaces where you want safety without visual clutter.

Alternatives

Non-electrical exit signs: Photoluminescent (glow-in-the-dark) and tritium signs label exits with no wiring or batteries—great where power is difficult or as a maintenance-light option. They complement, not replace, area lighting. See Photoluminescent Exit Signs and Tritium Exit Signs.

Central systems: Inverters or generators can power multiple fixtures from one source—useful for large sites. They centralize maintenance but add cost/complexity. Many facilities use a mix: unit equipment for most areas, central backup for critical spaces.

Conclusion & Next Steps

Pick the right mix of brightness, runtime, and durability, then wire it to unswitched power, test monthly, and log the results. Do that, and you’ll pass inspections—and more importantly—keep people safe when it counts.

• Map your egress routes and place fixtures for overlapping coverage
• Size batteries with a buffer for cold temps and aging
• Use remote-capable units to extend down long corridors
• Upgrade to wet-location/metal housings where the environment demands it