A Common Misconception About Battery-Powered Exit Signs
When Billy’s Motel was told it needed two exit signs at either end of the pool area, the news didn’t surprise him. But what did surprise him was the electrician’s quote to run new conduit and dedicate a power circuit to both signs—$700 or more, with the usual unknowns. Billy’s first thought: “Can’t I just install a battery-powered exit sign?”
Do Battery-Powered Exit Signs Exist?
Billy’s electrician dismissed the idea outright. Undeterred, Billy searched online and found what looked like a battery-powered exit sign from an international site. Despite hefty shipping costs, he ordered two. Months later, they arrived, and—after a few translated instructions—he wired the batteries and celebrated as both signs lit up.
But by the time he returned from celebrating, both signs had failed. He replaced the batteries, got a reinspection, and... they failed again. Billy finally realized what many facility managers learn the hard way: battery-only exit signs don’t exist in a compliant, long-lasting form.
Why Battery-Only Exit Signs Are a Myth
While many LED exit signs include a battery backup, they are not designed to run indefinitely without a wired power source. UL 924 compliance requires that exit signs operate for at least 90 minutes during a power outage, not full-time. A sign that only runs on batteries would burn through power quickly, and wouldn’t meet code standards or performance expectations.
What Are the Real Alternatives?
1. Photoluminescent Exit Signs
Photoluminescent Exit signs use glow-in-the-dark technology. The sign face contains a pigment that absorbs ambient light while the building is occupied. In the event of a power failure, it glows for at least 90 minutes—meeting UL 924 requirements.
These signs are ideal for areas that remain lit during occupancy, such as hallways, lobbies, or stairwells. They are available in two styles:
- Glowing background with dark letters
- Glowing letters on a dark background
Note: PL signs are not recommended for locations that are typically dark while in use, such as storage rooms or theaters.
2. Self-Luminous Exit Signs (Tritium-Based)
The only fully self-powered exit sign is the self-luminous tritium sign. These signs contain tritium, a radioactive gas sealed in glass tubes, that glows continuously without external power or charging. They are ideal for remote locations, outdoor breezeways, and environments where power access is impossible.
Available with 10-, 15-, or 20-year lifespans, self-luminous signs are widely used in places like movie theaters, transit stations, and industrial facilities. They require no electricity, no batteries, and no maintenance.
There are two important considerations:
- Regulatory Oversight: These signs are regulated by the Nuclear Regulatory Commission (NRC), even though the radiation is less than that of a smoke detector.
- Lead Time: Tritium signs often have long lead times due to production and regulation delays.
Fully Compliant, No Wiring Required
Both photoluminescent and self-luminous exit signs are UL and ETL listed, meet 90-minute emergency duration requirements, and require no wiring or batteries. For facility managers like Billy, they offer code-compliant solutions without needing to rewire your entire breezeway.