Battery life for emergency lighting

[lyledunn]

Manufacturers of self contained emergency luminaires, the type used in many buildings, either maintained or otherwise,in the past recommended a battery replacement after 5 years. I was wondering, given advanced battery technology does such a precaution still have to be taken

 

[coolfish]

Depends on the type of battery. Some batteries, although may have a listed life of 10 years, may fail in 3. Most would require replacement in no more than 7. Only a few will actually last 10 years or more. Or course, this also depends on the number of discharge and charge cycle, temperature, charging current, and a number of factors.

You can check reliability data for different types of batteries. In the absence of such data, I would consider manufacturer's recommendations.

 

[margaret695]

I have the notion that the five and ten year listed life whatever for emergency batteries may be determined in a similiar manner to the listed number of hours for metal halide lamps.

Like when sometimes the lamps start burning out way prior to the hours listed in lamp manufacturers' catalogues and clients start calling me about their dark parking lots and I of course call the lamp manufacturer..... the stock response is that the listed of hours is a "mean" of the test data...... meaning that a certain percentage burn out prior to the listed hours and a certain percentage burn out after the listed hours.

Therefore, in my opinion, following the manufacturer's recommendations is the way to go.

 

[porf]

For your consideration:

http://www.ccl-light.com/docs/exit/exit3.html

No batteries required.