For emergency lighting, what battery types are the most commonly used?

There 2 main approaches to this. Either you use a CBS(Central Battery System), in which contains many batteries and provide power to the emergency lighting until the generator starts, or you have 24VDC batteries beside each lighting fixture.

1. Wet Cell Batteries (Lower Cost, Heavy weight, maximum 1 to 2 years life time depends on usage). These are the same batteries use in vehicles.

2. Gel Batteries  (Heavy weight, costly, longer life than Lead Acid batteries)

3. Dry batteries (Lighter weight, more costly, longer life) 

Different Chemical Compositions:

1. Lead Acid

2. Nickel-Cadmium (NiCd)

3. Nickel-Metal Hydride (NiMH)

4. Lithium (Li)

5. Lithium Ion (Li-Ion)

6. Lithium-Ion Polymer (Li-Po)

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.

There are two types of Battary are used in emergency lighting:

1. Sealed lead acid batteries - low cost, 

2. Nickel-cadmium batteries - high cost but more life

Moreover, it might be self-contained battery system (Light fixture contain small battery with re-charging circuit) or CBS system where the batteries are located in specific Room/Rooms and through special panel it fed the Emergency light.

Depending on the Surrounding Environment, if you can provide ventilation and not bear cost then go for the Led-acid(low life) but a better approach is to used sealed Nickel Cadmium batteries for they save your maintenance cost and are more durable

lead acid battery are use in emergency light commonly used

It is depend on type of light fixture. Example if light fixture is having inbuilt battery type than that battery will be dry-cell type. Or if light fixture is having 110V DC converter than station battery bank will be wet cell type.

• Sealed lead-acid batteries (the same type used in cars)
• Nickel-cadmium batteries

Mostly Two types of batteries are used:

• Sealed lead-acid batteries (the same type used in cars)
• Nickel-cadmium batteries

we can use led acid battery for emergency light.

Lead acid batteries or dry cell batteries