Introduction
A lighting device with an emergency battery pack switches on mechanically once a building experiences an influence outage. Emergency lights square measure normal in new industrial and high occupancy residential buildings, like faculty dormitories, apartments, and hotels. Most building codes need that they are put in older buildings still. All emergency lights and lighted staircase signs use an emergency power supply for powering the lamps. To ensure continuous readiness and operation of the emergency lightweight, these batteries square measure reversible. Electronic equipment at intervals the emergency lightweight each charges the battery and ensures that it stays charged. How to select a NiCd battery or lead-acid battery for it? Let’s move to urge the solutions.
What Kinds of Emergency Battery Pack Applied in Emergency Lighting?
A variety of various battery varieties square measure utilized in emergency lighting. Most varieties square measure as followed:
1. Lead-acid battery.
These were usually used until recently in self-contained emergency lighting, like a twin-spot, and square measure is still widely utilized in central battery systems. Outside these specific applications, lead-acid batteries square measure currently seldom utilized in emergency lighting.
2. Nickel calcium battery (NiCd).
Cadmium is very deadly and is one every of solely half a dozen substances illegal by the EU’s RoHS Directive. However, AN exemption is in situ for
batteries in rechargeable emergency lights as a result of until recently there are few appropriate alternatives. NiCd batteries square measure wide utilized in complete emergency lighting and emergency conversion kits. Take a complete staircase sign as AN example. Most of those use nickel metallic element (NiCd) batteries, placed within the fitting.
3. Nickel-metal binary compound battery (NiMH).
These batteries square measure wide utilized in place of NiCd in emergency conversion kits wherever they need some (slight) benefits in some applications. It’s common that a NiMH battery to consist, during this example, of 5 cells. Visually, the most distinct is that NiMH cells square measure slimmer than NiCd cells.
4. Lithium battery.
There square measure many varieties of metallic element batteries and they are getting widely used a lot for emergency lighting. They need several benefits over lead-acid, NiCd, and NiMH thus their use is increasing speedily.
Which Types of Emergency Battery Pack Ought to Be Chosen in Emergency Lighting?
Nowadays, many varieties of batteries square measure used most in emergency lighting, however which one is best for it?
Advantages of lead-acid batteries:
1. Lowest value
2. Higher resistance to heat and cold
Disadvantages of lead-acid batteries:
1. Larger size
2. Heavier weight
3. Should stay upright
4. Broken by “deep cycling” (allowing the battery to lose charge)
Advantages of nickel-cadmium batteries:
1. Smaller size
2. Lighter weight
3. Maybe oriented in any direction
4. Longer life
5. Liable to extremes of warmth and cold
Disadvantages of nickel-cadmium batteries:
1. Higher value
2. Should be entirely discharged sporadically (the annual take a look at takes care of this)
3. Have a “memory” so if it’s not charged the primary time, it ne’er can settle for a full charge
What’s a lot of, typically, lead-acid batteries square measure utilized in steel enclosure emergency lights and nickel-cadmium batteries square measure utilized in thermoplastic housing emergency lights. Lithium iron (LFP) batteries appropriate for emergency lighting?
Lithium iron phosphate (LiFePO4, or LFP) square measures alright suited to use in emergency lighting.
When compared with alternatives like nickel-metallic element (NiCd) and nickel-metal binary compound (NiMH), metallic element iron phosphate (LFP) batteries have many advantages:
1. Energy efficiency.
LFP is a lot of economical than NiCd in two ways in which.
A. Self-discharge.
All reversible batteries lose charge over time, however, with LFP the speed is merely 3-5% per month. NiCd will lose V-day within the initial twenty-four hours, falling to 10-20% per month (depending on temperature) subsequently. The result of this is often that the charger in an emergency fitting with NiCd or NiMH batteries is functioning virtually frequently, whereas the charger in AN LFP circuit is functioning at low current in brief and rare bursts.
B. Charge efficiency.
Energy is lost within the variety of heat throughout the charging method of any battery. With LFP the charge potency is extremely high, about 95%. With NiCd, the charge potency is additionally terribly high, however solely within the earlier stages of charging. Once the battery reaches the seventieth capability heat starts to be generated and also the charging potency falls to 85%. It is often important as a result of traditional use a NiCd battery in AN emergency lightweight fitting is frequently trickle-charged to stay at close to 100 percent capability.
2. Long life.
LFP batteries have very little memory result thus their performance remains virtually constant until they reach the finish of life, typically outlined as seventieth of rated capability. Typically, an LFP battery can have a lifetime of 8-10 years.
The performance (power storage) of NiCd and NiMH declines speedily with each charge/discharge cycle, order that they generally ought to be modified when three or four years. The routine testing of emergency lighting needed by SB 5266 contributes to shortening the lifetime of NiCd batteries. It’s conjointly common for NiCd batteries in new-build comes to fail within their initial year of life if they need been totally put in the construction section once the mains power would unremarkably be shifted utterly nightlong. The ensuing nightly discharge and daily recharge degrade the NiCd batteries to the purpose that they’ll flow from for replacement within the primary year of occupation.
3. Extreme temperature performance.
A. High temperatures.
LFP is unharmed by ambient temperatures up to 60ºC, whereas NiCd and NiMH can only tolerate 55ºC and 50ºC respectively.
In low temperatures, LFP performs well down to -20ºC, but NiCd and NiMH will not deliver the charge needed to run emergency lighting below 0º
B. Environment.
Cadmium is banned under the RoHS Directive because it is a dangerous pollutant. Cadmium is highly toxic. Cadmium is highly toxic to almost all animals and many plants. It is also very persistent in the environment and is not easily combined with other elements that would render it harmless. NiCd batteries, therefore, have to be recycled with great care. LFP batteries must also be recycled, but the materials used are inherently less harmful than those used in NiCd and NiMH batteries. Cadmium has limited future use. Now that superior alternatives to cadmium are available for use in batteries it is to be expected that the RoHS directive will be amended to eliminate the exemption that has been allowed till now (2020).
How to Step by Step Replace the Emergency lightweight Battery Pack?
STEP ONE – Take a screwdriver and open up the housing.
Most emergency lights can take a Philips head, although some venturous locations of vandal-proof luminaires can use a special hex driver bit. Hopefully you or your maintenance department unbroken the enclosed bit once the device was purchased.
STEP TWO – Find the right wires for the emergency battery pack
Currently since you just have removed the plate you may be given millions of wires (don’t worry it’s normal). A number of these red, black, blue, or white electrical wires can lead from the AC electrical passage to a voltage electrical device that results in the shift circuits. One, two or many wires connect the printed circuit to the battery.
STEP THREE – Chose your emergency battery pack
Counting on your emergency lightweight, the emergency power supply can either be a sealed lead-acid (SLA) or Nickel metallic element (NiCd) battery kind. SLAs tend to appear like baby automobile batteries, whereas NiCd typically fit traditional social unit abdominal aortic aneurysm batteries, sealed in an exceedingly protecting plastic shrink wrap. Most batteries can slide out of the unit once the leads are off from the + and – contact points. Some cells are going to be housed in an exceeding harness that you want to additionally take away.
Conclusion:
There are several selections for emergency lightweight and emergency battery packs, by collecting all this info before ordering a replacement battery for your emergency lightweight, you’ll higher compare the obtainable choices and opt for the right one to satisfy your desires and your budget. Quality emergency lightweight batteries will facilitate creates your home or your business safer throughout an influence outage.
