Emergency Lighting 1

This little piece follows on from out previous lighting segment which involved people making their own emergency lighting from LED strip powered by a regulated 12 volt supply from a car battery as these are cheaply obtained and most practical people can make them to suit their applications and needs. What if you lack the ability and confidence to make your own or you physically cannot make your own because of injury or illness and underlying medical conditions; or just because you are not a practical person who cannot be bothered.

We will look at the latest technologies and understand their meanings and look at some of the recent advancements in lighting technologies and decipher this into understandable language so people can cut through the sales spiel and rhetoric and make informed choices and not become ripped off.

What is emergency lighting? Basically it is any form of lighting which has a basic function or functions and in its basic form we can see this in hotels in what is called maintained lighting and non maintained lighting and understand what it does and why. In a hotel you have to cater for people of all ages and abilities and generally you have your normal lighting switched on as most hotels are dark and this is maintained lighting; if the hotel had an incident such as a fire or other reason it lost power the maintained lighting would go out and the owners potentially have many guests who cannot see which is normally fine until they have to evacuate the hotel. In such cases the non maintained lighting kicks in and is triggered either by a power loss to a lighting unit or by a light level sensor or both as non maintained lighting incorporates a battery pack which is trickle charged by the mains power until it is charged and if this mains power is not detected it switches the battery pack on to power the lighting.
In many instances the emergency lighting would only be to illuminate signs such as emergency exits and in larger hotels this would highlight the emergency egress such as a way to the stairs, and the actual emergency route from that part or section of the hotel. In posher hotels their longer and darker corridors would potentially have ambient lighting which is just enough lighting to light the route of the emergency exits and include other areas such as stairwells for a specified time such as for 30 minutes before the batteries die. Some hotels have these ambient lighting units in more upmarket rooms.

Now we need to understand our needs and requirements and bring this knowledge together to make informed choices of what type of lighting we need and why, and what style of lighting we need and for what period of time we may need it for as a unit with a runtime of 2 hours is no good if our power is off for 5 hours.

Possibly the most popular enhancement in recent years to lighting is the LED as these have improved massively to the point where they are more powerful than traditional filament bulbs and consume less power for the same light output and it can come in a range of colours. Single chip LED’s were traditionally only machine made and this cheapens them to less than that of a traditional filament bulb which makes them attractive and as they are purely machine made they have a more consistent quality and are more durable than a traditional filament bulb and they can be easily waterproofed which is another bonus.
Our second best enhancement is LED control electronics as traditionally you had an LED driver which provides control of either the supply voltage or the supply current to a maximum number of LED’s and this is important as an LED will continue to suck current to the point it will blow if the current is not controlled.

As LED technologies advanced the single LED chip became more powerful and emitted more light for less power consumption and also ran hotter and some ran so hot they self destructed through heat damage and to improve the life of the LED they discovered they lasted better if run at or around 60° centigrade which was apparently the sweet spot for most applications. Technologies advanced further and they discovered that they could manufacture even smaller LED’s and they had the machines to do it and they could better control the heat if they manufactured these LED’s and fitted them to a heat conducting substrate and chose aluminium as it was readily available in foil and could be had as a thick foil. Using an aluminium substrate was a good thing as not only did it conduct heat away and cool the individual LED chips but it equalised the heat between individual LED chips so they all ran at the same consistent temperature which equalised both voltage and current consumption and the light output of each individual LED. These new substrates containing many individual LED chips were called an LED array or simply array for short and had become so small they needed identifying and in equally simple terms they were numbered in accordance with their size and of you read the last article on LED strip you will notice reference to the 2835 chips.
Originally we had the 5050 chip and this designated the array as 5.0mm X 5.0mm so the chip was 5mm square and these early arrays are all but obsolete now and currently the 2835 array is the most popular size and is 2.8mm X 3.5mm so a rectangle and not a square.

Control electronics also moved on and kept up with the LED advancements and became equally smaller and better controlled the power to the LED by controlling both the voltage and current and were so small they could be mounted with an LED array on the substrate and they were all connected by gold or other threads made from precious metals. When the control chip could control a number of LED arrays we got the LED tapes which could be cut and they were wired series parallel and the chip controlled a specific number of LED’s for that section of the LED tape. We also got a new kind of LED array which was also wired series parallel and the control chip was installed on the LED array to give something called a COB or Chip On Board and you merely soldered your power supply wires to it and the chip did the rest.
More advancements came with the Lithium Ion battery (Li-on) as these were cheaply made solely by machines and they replaced the then normal rechargeable batteries which were generally either AA or AAA sized Nickel Cadmium (Nicad) cells or Nickel Metal Hydride (Ni-Mh) cells which were often used to replace dry batteries. These early rechargeable batteries had a major issue and this was they were only 1.2 volts each and a dry battery was 1.5 volts and if you replaced a dry battery with a rechargeable cell you lost 0.3 volts per cell and if your item required 6 V it would need 4 X dry cells or 5 X Nicad or Ni-Mh cells to replace them to maintain your required 6 volts or you only got 4.8 volts with 4 X rechargeables and they replaced the voltage by using the current capacity instead.
Li-on cells were totally different and unlike a traditional rechargeable cell they could discharge nearly all their capacity in one hit and this gave a tremendous discharge rate which, if unchecked could be dangerous and cause fires; but they came with a nominal battery voltage (NBV) of 3.7 volts. This was useful as traditional rechargeables had a NBV of 1.2 volts and 3 connected in series had a NBV of 3.6 volts.

Our final advancement was that of charging the battery or batteries and again battery control chips kept up with battery advancements and again some tiny charging control circuits were introduced and they became known as smart charging controllers as they could differentiate between different battery chemistries and charge them as required. Many also had a maintenance function which would revive many batteries and these ensured batteries were always charged to their optimum.

Now we are fully up to date we can disseminate some of the technologies and begin with the early LED systems fitted with LED drivers as these are known as first generation systems and are very poorly equipped when compared to the later systems. These later systems came with COB technologies and were called COB chips or COB arrays and had the on board COB chips to control both voltage and current and were called second or latest generation technologies and many also had Li-on batteries and smart charging for on board batteries, we want the latest generation.

For the purposes of this article I will refer to Amazon as everyone can access this and our first problem is that many lights use the same components and are merely badge engineered versions of the same lantern and we must watch carefully for this particularly as you can often get the same item with a different badge much cheaper. Many other lanterns use the same internals and currently the 30 chip LED array seems popular as many different makes use it and as this comes as a COB unit the control electronics are also the same and the only major difference could be the batteries which could be of a cheaper brand or smaller or lower output than other models so the devil is really in the detail.

What are our needs and requirements and how many emergency lanterns do I need and what type do I need as they come as dry battery, rechargeable batteries, wind up charging and solar charging and some have many of these features. What do I want to illuminate? Why do I want to illuminate it and what can I do with other things.

Light output is measured in Lumens and a 50 lumen tactical torch with the light focused through a lens would easily light up a distance of 100 metres with a spot beam but put that same 50 lumen LED in an omnidirectional lantern (shines the light all around) and it wouldn’t be as bright as a candle. For an average room I would suggest 400 to 1000 lumens is ideal and I would suggest going for a temperature of 6000K as this is Kelvin and bright daylight is around 6400K and getting nearer to bright sunlight means you can see more and if you go for the softer 3000K you will get a warmer light but will see less. Remember the brighter the light the shorter the burn time (running time) before the battery is flat and for an emergency lantern I would aim for a burn time of around 4-5 hours as a minimum and remember the long burn times of some lanterns are only at low power settings and not at normal power settings so watch for this.
Using a rechargeable lantern with a suitable light output is fine but if it has only one setting then its run time will be fixed by the state of the battery charge and as your eyes become acclimatised to the dark you can turn your lighting down if you have multiple light settings to increase your run time and turn it back up if you need the light to go to the toilet for example. Much the same applies to those powered by dry cells. You can select another option of having a lantern permanently plugged in and if the mains power goes off the lantern switches on automatically as these lanterns are available, albeit it at a price, and are handy for elderly, disabled, or inform people who regularly get up and need the light.
How many emergency lanterns do I need? This question should be rephrased to how much lighting do I need for the people in the property as children will automatically demand a lantern for the pettiest of reasons as they have been raised with abundant light upon demand and having a single lantern to go to bed is not a reasonable use of light generally. Many adults will not need a light to go to the toilet or bed but this can be combined with what other light sources do I have as many prepared properties also have multiple torches which can also be used away from a lantern meaning the lantern can remain in one spot to illuminate it.
If you may need to go outside you need a lantern which will cope with the weather conditions and as a minimum your lantern must be water resistant to rain and remember if you have a log burner you may have to go outside to collect wood or you may need to light a garage or shed to collect tools to repair something or even look in drawers for torches. In reality a power outage can last for several minutes or many hours and having a second lantern increases your run time as your first lantern may run flat and you simply switch on your second lantern as a lit property in a power cut is less likely to become a target as it says someone is up and potentially watching and if I break in I will be seen and heard. If you have a lantern using dry cells you only need keep spare batteries and run time is less of an issue as you simply replace the batteries if they become flat and your run time lasts until you run out of batteries.

If you have a lantern using dry cells you may have another option and this is to use rechargeable cells and if a single Lithium Ion battery is 3.7 volts and 3 X rechargeable Nicad or Ni-Mh are 3.6 volts then they are generally interchangeable as the unit may require 3.5 volts incoming voltage and both these exceed this. In many cases many models actually advertise the fact you can run rechargeable batteries instead of dry cells and this is down to the electronic controller as many use the same type across their model range for scales of economy to both charge rechargeable Lithium cells and run the LED chip and if this is charged from a USB port it must be able to handle above 5 volts incoming from a USB socket. If it can also be charged from a vehicle cigarette lighter it must also be able to handle an input in excess of 12 volts and potentially 24 volts of a lorry or commercial vehicle. This also means you are only limited by quantity of charged cells you have combined with the number of dry batteries you have.

Other charging options exist and many people keep making the same mistakes and the other options are solar and wind up lanterns and a pure wind up lantern generally runs for 20 minutes from 1 minute of winding but it isn’t that simple is it. In one word YES it is that simple and in another word NO it isn’t that simple and this comes down to your lantern.
Basic wind up lanterns use older wind up technologies and actually this is a good thing as you are only charging capacitors which are actually storage capacitors and will charge up reasonably rapidly and discharge slowly hence 1 minute of winding for 20 minutes of light, and actually these older types are my preferred option. Other types of wind up lanterns swap storage capacitors for small batteries known as on board batteries as they are contained within your electronics to maintain your systems and are popular in computers, dash cameras, and other electronic items to maintain their memory which means they are designed for continual charging and slow discharging. Wind up or kinetic charging for on board cells does not work as these on board cells are designed for slow charging over many hours and do not respond well to rapid charging and this quickly damages them and can literally trash them in one rapid charge which will render your lantern scrap.

Solar charging is the latest technology and again is full of pitfalls for the unwary and many people fall for the spiel and pure sales talk and end up with a poor product which simply doesn’t deliver what it was supposed to deliver. Many people assume you can put the lantern in the sun and it will charge it but to date the small solar panels fitted to these units in inadequate as it will NOT provide sufficient power to charge a battery and unfortunately many people have found this out the hard way and lost money. Many people make the same incorrect assumptions that if they stand their solar lantern on a window sill it will stay charged and this is incorrect as solar charging requires something called ultra violet light to charge and most modern windows have a coating on to block out the ultra violet light so immediately an inadequate system fails through lack of UV light. When you see the adverts claiming this wind up product will give you unlimited light and act as a 5000Ma power bank and run solely from a wind up system you know this is at best misleading information and at worst pure lies designed to part a fool from his/her money. Most solar lanterns also have a rechargeable battery which are charged by a USB connection and often advertise them as requiring 5 hours to recharge so ask how a 1 minute wind can replace the charge a dedicated charger cannot and the answer is simple, it cannot.
In a best case scenario it would appear that a solar charger with direct exposure to the sun may overcome something called “internal discharge” which is something all batteries have and this is that over time they lose some of their charge and solar may slow this down or replenish some of it.

This raises the question of how many lanterns do I need and where do they fit into my emergency lighting scheme and generally I would suggest one focal point for a fixed lantern and generally this would be the living room or kitchen where the family normally congregates. I would suggest the brightest lantern goes here and remains here and should be located in a position which offers the best light output and lights essentials such as a gas cooker which may be used to boil water for drinks or cook food if it is the electricity which is out.

What type of lantern should it be? Normally a rechargeable lantern with multiple light settings would be ideal and if you are congregating in the kitchen and living room you need two lanterns and if you leave your kitchen lantern on and use its lowest setting you will increase its burn time and be able to see it if you re-enter the kitchen and turn it back up.

Do these have to be rechargeable li-on cells, no they can be the older Ni Mh cells if you have dry cell lanterns and they support these rechargeable batteries and they can be beneficial as a set can be left in a lantern and even if they partially discharge over time they will often provide enough light to allow you to fit charged cells to your second lantern. Once this is illuminated you can run your first lantern until it runs flat and swap its discharged cells for fully charged items and use your second lantern to provide the light to enable this.
Can I have a standard Li-on lantern with USB charger and a second dry cell lantern which supports rechargeable NiMh cells, yes of course and if you run your Li-on lantern flat you still have your NiMh lantern to rely upon and if you buy bulk packs of cells and keep them charged you can have several battery changes.

What about torches and can they be used alongside lanterns, in a word yes because emergency lighting is not simply about one type of lighting and encompasses a mixture of lighting to suit your needs and requirements and a third lantern maybe used to illuminate stairs for example. It may be left on its lowest setting at the bottom of the stairs to clearly mark the stairs and if someone needs to go upstairs they turn the lantern brightness up and take it upstairs with them and when they come back down they turn the brightness back down and return the lantern to where it was. Someone may find a torch useful to get to a car for example or to go down the garden or simply to identify any medication they are on and take it or make connections to their consumer unit from any generator they may have so they can run mains power during a power cut.

Is a standard USB rechargeable lantern the best option, no because every case is different and some people may prefer the dry cell lanterns with the capability to run the rechargeable Ni-Mh cells and use a digital charger to recharge them? Normally these come with the charger unit which is supplied from a 12 volt transformer which is plugged into the wall socket and delivers 12 volts to the charger and if you have one of these chargers they often come with a car charger so you can plug the charger into your cigarette lighter to get the 12 volts it requires. If you have two 3 cell lanterns and buy a bulk pack of 12 X rechargeable cells you can use 6 cells in your two lanterns and put four cells in your charger and plug it into your car’s cigarette lighter to charge them and four of your remaining 6 cells will be charged and the remaining cells can be charged after.
If you really want more flexibility then another option exists and this is either the car or leisure battery and currently the most popular can battery is called the 039 battery and you can get these for under £40 by judicious shopping. Leisure batteries are more durable and cost more money and basically they last longer and stand more abuse then a car battery but either can be fitted with a cigarette lighter socket and most auto electrical supply outlets supply them cheaply and you wire them to your battery and you have a cigarette lighter socket. Plug your charger into this and it will charge your rechargeable batteries and as long as your car or leisure battery is charged it will give hours of recharging for your rechargeable battery cells for your lanterns.

If you followed the earlier version of emergency lighting and decided to get yourself a leisure/car battery and bought some lighting strip and made your regulated circuits and your power goes off you may need sufficient light to recover them from storage and install them in your home. You can recover your battery and put it in its designated spot and often these will be in a shed or garage and the lantern light will be useful in recovering them as unlike a torch you can put the lantern down and use two hands to get everything out. Once in the house the same lantern can be used to attach the connections to your home made lights so you have your home illuminated leaving only the more obscure areas to be lit and you can use your lanterns for this.

What it does show us is that lanterns are an integral part of emergency lighting and if your power is off and it is anticipated to be off for less than an hour then for most people a couple of lanterns would suffice; if your electricity is going to be off for longer periods then your lanterns are useful in recovering and installing other systems to cope with longer periods of lost electricity. As every need and requirement is different it would be for the individual to decide how, what, and where for their own specific systems.

Its official; electricity is going to be cut off for up to 3 hours at a time to save energy for heating and it has been announced today, thursday so working out a lighting scheme for emergency lighting is now more important than ever, but this is pure stupidity IMO and in many others.

Lets get to the crux of the matter here as this is rather silly as those switching over to heat pumps know they operate solely upon electricity so switch the electric off and no heat pump and already they contradict themselves and if you have gas, oil, or most other types of heating the boiler is controlled by electronics which require??? yes you guesed it electricity. The reality is that it isn't so people can heat their homes at all as by cutting the electricity you cut nearly all forms of heat as they rely upon electricity to run them and particularly their circulation pumps.

The only way around this is to have either an open fire burning coal or a log burner burning logs.