Many times over the years I have heard the statement, “My emergency light does not work, it must be defective.” Nine times out of ten, the unit is not defective but the battery is dead.
There are numerous reasons why the battery is dead. Two of the most common are the misapplication of the battery to the environment in which the unit will be installed, and failure to inspect and maintain the units.
The majority of emergency lights are supplied with a maintenance-free sealed lead calcium battery. These batteries typically have a 5–7 year life span as long as they are maintained in an environment between 60° - 80° F. As the temperature of the battery’s environment gets above the recommended range, the chemical reactions within the battery are accelerated, leading to a diminished battery life. As the temperature gets below the recommended range, the chemical reactions are slower which reduces the output of the battery.
The environment that the emergency lighting unit will be installed plays a very important part in selecting the type of light and battery to use. It’s like picking out the proper vehicle to use when going off-roading. A Corvette will work initially, but when the conditions get to be extreme, it will fail.
There are four main types of battery being used in emergency lighting: Maintenance-free sealed lead calcium; Refillable lead acid; Maintenance-free sealed nickel cadmium; and Refillable nickel cadmium. Each of these battery types have their own characteristics and applications.
As already mentioned, the maintenance-free sealed lead calcium battery has a 5 – 7 year expected life in an environment of 60° - 80°F. The refillable lead acid battery has an 8 – 12 year life expectancy in an operating environment of 32° - 105°F. These batteries are shipped in a dry state and must be filled with sulfuric acid at the time of installation. Over time as the battery goes through the charging stages, water is evaporated from inside, reducing the battery level and exposing the interior plates. The fluid level must be maintained with distilled water. The maintenance-free sealed nickel cadmium battery has the widest operating range, with an expected life of 12 – 15 years in an environment of -4° - 158°F. The refillable nickel cadmium battery has the longest expected life, 20 – 25 years, and can operate in the coldest of conditions, -22° - 140°F. These batteries also require maintenance. They are initially charged with an alkaline solution of Potassium Hydroxide and are refilled like the lead acid batteries with distilled water.
The second major reason for battery failures is that the emergency light has not been inspected and maintained as is required. The Life Safety Code (NFPA 101) requires periodic testing of emergency lighting equipment under Section 7.9.3 of the code.
The basics of the code states that:
- Functional testing shall be conducted at 30-day intervals for not less than 30-seconds;
- Functional testing shall be conducted annually for not less than 1-1/2 hours if the emergency lighting system is battery powered;
- The emergency lighting equipment shall be fully operational for the duration of the 1-1/2 hour test; and
- Written record of visual inspections and tests shall be kept by the owner for inspection by the authority having jurisdiction.
(Excerpted from Life Safety Code 2003)
Most end-users / building owners do not even know that this code exists. Many places state that they do not have the time, the money or the manpower to spend on inspecting these units. Many people have gone to using the self-test / self-diagnostic emergency lights to make it easier to comply with the code. However, the Life Safety Code also requires written records of inspection of these units at 30-day intervals.
In short, we are talking about the safety of lives. Proper battery applications and emergency light inspections are very important; it could be your life or that of a loved one.
For more information on BIG BEAM Emergency Systems, Inc., call Paul Markee at 815-459-6100 or email pmarkee@bigbeam.com.
