Sealed Lead-Acid Batteries and Emergency Lights

All emergency lights require internal batteries to make them function. These batteries are essential to supply power to the lamps, in the case of a power outage. As such, they must be rechargeable, with a charge time of less than 24 hours and provide enough electrical current to keep the lamps lit for a minimum of 90 minutes when the unit is activated.

• 
  6 Volt 4.5 Amp Replacement Emergency Light Battery
  $12.99
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• 
  4.8 Volt 700mah Nickel Cadmium Emergency Light Battery Pack
  $12.99
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There are two types of rechargeable batteries used in emergency lights:

• Lead-Acid batteries
• Nickel-Cadmium batteries

Each of these two have certain advantages and are utilized in specific emergency light applications. Essentially, nickel cadmium batteries are used in thermoplastic emergency lights, where small size is an important consideration.

View our selection of Emergency Light Batteries

Most emergency lights, including steel emergency lights, wet location emergency lights and hazardous location emergency lights use lead-acid batteries. The primary reason for this are:

• Lower acquisition cost
• Higher capacity in amp-hours stored
• Capacity and self-discharge are not highly affected by temperature

Lead-acid emergency light batteries are available in 6, 12 and 24 volts and a wide number of wattage capacities to meet every need. For applications where a remote lamp head is attached to the unit, please indication this need when purchasing so that higher capacity batteries can be installed in the unit.

Emergency Light Batteries come in a variety of shapes and sizes. The 6 volt 4.5 amp sealed lead acid battery is one of the most common models found in emergency light fixtures. It is affordably priced and can ship today.

Lead-acid Battery Maintenance

Lead-acid batteries in emergency lighting are essentially maintenance free. Unlike earlier lead-acid batteries, the ones used today are sealed. This means that there is no requirement to check the water level in the battery and add to it as needed.

The monthly testing of the emergency light unit, using the test button, also tests that the battery is functioning. However, as part of the annual checking of the emergency light unit, disconnecting the battery and checking its voltage is required.

When checking any battery’s voltage, the measured voltage should be slightly higher than the nominal voltage. For example, a new 12 volt battery that is fully charged will normally read 13.2 volts. As the battery ages, the chemical components used to create the electrical charge lose their potential, this is indicated by a reduction in this fully charged voltage. A battery that checks at its stated voltage is very near the end of its life expectancy.

While you can check your batteries with a multi-meter, you are better off using an actual battery tester. The difference between the two is that the batter tester will put a load on the battery and measure the voltage under load. A multi-meter will only check the existing voltage, without any load. In some cases, a battery may check “good” with a multi-meter, but “bad” when put under load.

Replacing Batteries

Batteries should only be replaced with the same type. There are three issues here when we are referring to type:

• Material composition (lead-acid vs. NiCad)
• Voltage
• Amperage capacity

The voltage and amperage need to be the same to insure that your lights will illuminate to the right brightness level and remain lit for the required 90 minutes of time. Too low a voltage will cause your lights to be dim; while too high a voltage will blow the bulbs. An amperage rating of less than the original will not insure that your lights remain lit for the full 90 minutes in a power outage situation.

Replacing lead-acid batteries with nickel-cadmium causes problems in that the charging circuit is different for the two. Lead-acid batteries typically recharge in 24 hours, while NiCads recharge in 3-1/2 hours. The two battery types are manufactured with different connections to aid in identifying them. Lead-acid batteries typically have screw terminals, while NiCad batteries typically have wires attached to them.

Call us today at 800-480-0707 for more information on emergency light batteries, to ask a question, or place an order. Representatives are standing by so please call today.

By Jonathan Carter