Emergency Light Output Voltage To Battery

[Ravenvalor]

Hello,

I have a customer who has 19 - Cooper Lighting emergency lights model# CC-8 that use 12-volt, 18aH batteries. Should the output voltage from the emergency light to the battery under 'power on' conditions be 13-volts or higher? Can I measure the voltage with the batteries connected to the light? I called the manufacturer's technical support and the person that I spoke with seemed to indicate that the voltage probably should be at least 13-volts and that it was okay to test the voltage with the battery connected.
I normally do not spend any time testing emergency light output voltage but these particular ones look expensive.

Thanks,,,

 

[tom baker]

Thst sounds maybe a little low for float voltage. Do all the ems read the same?.
How old are the batteries?

 

[Ravenvalor]

Thst sounds maybe a little low for float voltage. Do all the ems read the same?.
How old are the batteries?

Most of them are reading about 13.5-volts. Some are reading 14 - 16-volts.
One is reading 11.5-volts. Two are reading 12.5-volts.
Some of the batteries that are still testing good could be as old as 19-years.
Some of the batteries that are testing good and bad could be as old as 8-years.
And some of the batteries that are also testing good and bad are only 2-years old.
Not seeing any patterns. The age of the battery does not seem to correlate with it being good or bad.
Thanks for the help.

 

[rnatalie]

Assuming we're talking about gelled-electrolyte lead-acid batteries (the most common), the charging voltage should never exceed 14.1V. Float charging can be between 13-13.8V and current limited (no more than1% of the battery rating). Charging a depleted battery can go up to currents around 25% of the capacity (that's just a rule of thumb, the units are different).

 

[Ravenvalor]

Assuming we're talking about gelled-electrolyte lead-acid batteries (the most common), the charging voltage should never exceed 14.1V. Float charging can be between 13-13.8V and current limited (no more than1% of the battery rating). Charging a depleted battery can go up to currents around 25% of the capacity (that's just a rule of thumb, the units are different).

Hey I appreciate the help....
The batteries are lead -acid.
Do you have any ideas why some of these voltages are reading higher than 14.1V? They did have a power outage a few weeks ago that lasted a full day. Do you reckon the batteries that are reading higher than 14.1V may be bad batteries?
Thanks....

 

[rnatalie]

They can go up a tad higher if they are flooded cell lead-acid. The lower voltages/currents are to keep from causing the gel to disintegrate.