Lights with Battery Packs

Benihana

Member
Location
Suffolk County, NY
Occupation
Electrical Engineer
This is a dumb question.

When a light is provided with a battery pack, will it always remain ON? Even in an instance where the light switch for that light is powered off? Or are they provided with something that allows it to sense when the actual normal power source is lost, which then kicks the battery on.

Any help greatly appreciated!
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
When a light is provided with a battery pack, will it always remain ON? Even in an instance where the light switch for that light is powered off? Or are they provided with something that allows it to sense when the actual normal power source is lost, which then kicks the battery on.
They have only one power input. The charging voltage also keeps the light off.
 

Strathead

Senior Member
Location
Ocala, Florida, USA
Occupation
Electrician/Estimator/Project Manager/Superintendent
This is a dumb question.

When a light is provided with a battery pack, will it always remain ON? Even in an instance where the light switch for that light is powered off? Or are they provided with something that allows it to sense when the actual normal power source is lost, which then kicks the battery on.

Any help greatly appreciated!
You can look up a typical wiring diagram. Just type in Bodine. In general, they have a hot, neutral and switch leg input. The hot usually gets interrupted by a test switch. Many of them today have 0-10V out and often times reduce the lumens of the LED's when on battery power.
 

raberding

Senior Member
Location
Dayton, OH
Occupation
Consulting Engineer
I think they can be switched. 3 wires - the unswitched ckt; a switch leg; neutral.
So they can be on-off like a "normal" light. Or if power is lost, they are an "emerg" light.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I too the OP to be asking about an egress light unit.

Yes, emergency ceiling lights have an always-hot feed to keep the battery charged and to sense power loss, and a switched feed for optional manual light switching to avoid running down the battery.
 
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