Here comes OSRAM Nightlux

After using the Ikea DIODER light for a while, I am starting to feel that sensor activated lights can be pretty useful, especially if it is battery powered as it can be extremely convenient to set-up and there is no need for any unsightly cabling.

And so, I was searching for a motion-sensor activated light to shed some light to commonly used places such as the toilet. I think it is quite wasteful to power up florescent tubes only for 1-2 mins at a time at night especially when the lifespan of florescent tubes depend partially on the number of on-off cycles. Current LED technology is good enough to offer relatively usable light output while using little electricity and this makes it practical to use batteries to power them.

So, here comes the OSRAM Nightlux. Its not a new product. A date stamp on mine has the year 2007 on it. Got it for $19.90 from AMK hub's fairprice. It is by no means cheap for a product with only 3 ultra-low power LEDs but it is worth the price. As I shall explain below:

 

Yeah, I was so excited that I ripped it out without taking a picture first. As mentioned in the packaging, it uses 3x AAA batteries, operates by sensor and knows to turn on only when there is low light. I have to say that the light sensor is pretty good. My toilet is rather dark even in the day but it doesn't waste energy by turning on in the day. The motion sensor has quite a good range too. It switches on the moment I walk into the toilet. I didn't have to find some strategic spot to place it so that it can detect me.

 Of course, its a far cry from my main toilet lighting it is good enough for me to do anything I need to do in a toilet.

 Yep, its on! The lights are rather directional and can be swiveled up and down. The LEDs are not bright enough if designed to be a "floody" light. Hence, the reflectors make the beam slightly focused so that the light only goes to where you need it to. Its a slight trade off but its a well thought out design.

 Here's the back of the light where there is a switch for OFF, 10sec, 60sec and constant ON. I would prefer if there is a 30sec option, but I'm fine with it being on for 60sec. A word of caution, after it switches off, it takes about 3sec to turn on again.

 The back plate contains a strong magnet for sticking on to metallic objects. It comes included with a metallic plate with sticky tape on it. Unfortunately, the sticky tape isn't sticky enough. Mine dropped from a height of about 1 metre. Sob Sob.

The magnetic back plating.

Yep, it doesn't switch on in the day. The finish and build is very sturdy and it is a nice addition to a clean tiled wall. The 3 LEDs take a total of 0.3W(rated) which means the batteries should last about 13 hours of continuous usage. Again, if I were to activate it 10 times a day, I mean night, then it should last about 2 and a half months, which is pretty good.

I will be fixing this to the ceiling once I get my hands on stronger sticky tape. If it works well then maybe I'll get more of these for other parts of my house


UPDATE:

After 7 months of using this, I decided that it was time to get another one to light up my room. It is particularly useful for me because at times I needed to enter my room simply to take something out of there. Previously, I would have to switch on my fluorescent lamps for less than a minute before switching them off. Fluorescent lamps don't like on-off cycles as it reduces their lifespan.

Using this to provide just enough light for me to get around my room reduces the need to switch my main lights on.

There are also several things that I have noted along the way:

Changing 3x AAA is a chore
Devices that use odd numbers of batteries make it difficult for battery changes as there will always be 1 lone battery sitting out from the rest. This is annoying because that lone battery will have to be used separately from the batch it came with so you can't "pair" up capacities together.

It works even under very low voltage
Since I didn't always use 3 similar batteries in the Nightlux, I turned to mixing and matching batteries. When it became dimmer again, I checked the batteries with my voltmeter to see which one was the culprit. At times, I found the dead battery to be less than 0.5v. Surprising that the Nightlux could operate even with such a significant voltage drop. It is difficult to notice the drop in brightness since I use it only for very basic purposes. I consider this its strength and also its weakness because on one hand, the circuitry is very versatile, but on the other, it will damage rechargeable batteries if they was allowed to run this low before charging. Hence, I strongly recommend against using rechargables in this product. If only there was a low-voltage warning light...

The light sensor is very smart
Most motion sensor lights would simply turn on when they sense motion, regardless of the brightness of the location. You know the designer of this product have thought long and hard when coming up with this little thing.

If it was using AA batteries instead...
The Nightlux would last about 6 months per battery change. This is more economical considering that AAs have more than 2x the capacity as AAAs but comes at a similar price.

Ikea DIODER drawer light!

All those who knows me would know that I really like lights and batteries. While I was browsing IKEA's furniture online, I chanced upon a little LED strip light called the "DIODER LED battery-operated lamp f/drawer". The reason for quoting the full name is because there are many other LED strips in the DIODER range of lights.

There is very little information about the product on the website

1) Designed for a drawer
2) Has a motion sensor (sleek sia!)
3) Turns on for 15sec when there is ambient light (open drawer) and 5sec when totally dark (closed drawer)
4) Takes 6 AAA batteries (Wah lao eh, so many!)




 




*picture belongs to IKEA

When I came home with the product, it struck me that I never really need to light up my drawer. I couldn't remember when was the last time I had to grab something from my drawer when my room is completely dark.Other than that, I have to say that the design is really well thought out for a drawer light; the placement and the range of the sensor is perfect for a drawer. The light is directed at an angle so it lights up most parts of the drawer.

 

6 LEDs spread along the entire strip. Very clean and neat layout. No switches, just motion sensor.

Tada! And behold, there is light!

The whole package is very light. It comes with screws for a permanent fixture but a simple double-sided tape should suffice. The sensor is on the "negative" side of the battery compartment and is facing in the opposite direction of the LEDs, which is perfect for using it in a drawer. The light has a warm colour temperature which resembles the lovely incandescent lamp but without the low efficiency. I found that it uses a negligible  0.2mA on stand-by (to power the motion sensor) and 87mA when lighted. The current draw is quite acceptable for AAA sized batteries. A typical AAA alkaline has a 900mAh, which means it should last 10hours of constant usage. Now, assuming that I activate it 10 times a day, one set of batteries should last me 8months. The designer probably thought of this so that you don't have to change batteries too often and waste money on batteries. Battery powered LED lighting is always centred around efficiency and this is no exception.

The backside of the strip. Again, a clean flat surface that is suitable for double-sided taping. I chose to stick 3M's velcro tape for easy removal so that it is a lot easier to change the batteries next time.

 Here's an option for those who like to put their face near to the printer to see a nice printout being born.

Coolest printer ever!

 Here's with the battery tube removed. I'll recommend that you buy the 10pack IKEA AAA batteries since it sells for SG$2.50

A close up on the cheery yellow batteries that IKEA sells. 

 Instead of using this in a drawer, which is pretty useless for me, I chose to put it in my wardrobe.

 Really sleek lighting without the need for wires. Excellent stand-alone light.

 Here's from another view. An LED strip works very well for lighting up wardrobes with lots of obstructions as it does not form harsh shadows that a single LED light source would.

It works nicely for times when I just need to get a piece of clothing from my room without switching on my main room lights. Even in a rather dark room, it still lights up for 15sec. It would be nicer if it lights up for a longer period though. Maybe 30sec or 1min will be great.

It is not much but it does light up well enough for me. Being a warm coloured light, the colour rendition is pretty good. Great for picking out clothing. The DIODER is activated from sliding the wardrobe door past it. The sensor range has a maximum of 10cm. However, if placed too close to the sliding door, the light reactivates after lighting up. Check before securing it permanently!

Another view with the wardrobe door closed. It makes for a good night light. However, 15sec is only good enough for me to put down my glasses and head straight to bed. It would perfect if it could be adjusted to light up a for 30sec instead of the short 15sec.

UPDATE:

Problem regarding continuous re-activation:
1)My first set of batteries died after just 1.5months of use! But that is because there were a few times when I took it out to play and stuck it back in my wardrobe without noticing that it was continuously re-activating itself. Always check if distance of the door from the sensor is causing the light to re-activate. Check during daytime and nighttime as it seems that having ambient light may affect the distances where it re-activates continuously.

Signs of battery weakening:
2) One thing I noticed when the batteries were nearing the end of its life was the increasing likelihood of missed activation. I.e. the sensor misses detection when I open the wardrobe door too fast. After changing the batteries, it activates no matter how fast I open the door. You can take that as a cue to re-charge your batteries if you are using rechargables!

Termination voltage is suitable for recharables:
3) The 3rd thing and probably most important thing I noticed was that the dead 6x alkaline batteries was at 6.50V. This translate to 1.08V per cell. That means that you are unlikely to over drain and damage your expensive NiMh cells in the event of continuous re-activation. Not sure if it is purposely designed this way, but this is very thoughtful!

LEDs seem regulated:
4) Unlike cheap lighting products that will dim as the batteries go weaker, I did not notice a change in brightness even during the last days of my batteries.

In all, I am quite impressed by how much thought has been put into this product(whether knowingly or unknowingly). Now I dare to use rechargables for this product. It is not only elegant not only in looks but also its electronics. It is rather high in price, $29.90 for a 6 LED strip light, compared to the DIY option. However, it looks a lot sleeker and a lot smarter.

How to use public transport in Singapore more effectively

A recent video about "changing 5'Cs" of Singapore stated that a car in Singapore costs as much as 19 of the same car in the US. That is quite sad considering that most Singaporeans don't earn 19 times the salary of an American. Nevertheless, life goes on and public transport is the way to go in Singapore. Buying a car as a young adult is like committing financial suicide. A "budget" Toyota Vios, the kind of car used by beginner drivers, now cost a whopping $120,000+ (http://www.sgcarmart.com/new_cars/newcars_pricing.php?CarCode=10397). This means that if you decide to set aside $1000 per month as installment, you'll only complete your purchase in 10 years, which is, the time when your COE ends...

As much as I love driving and cars, I know that the only time when I can well afford a car is when I am near retirement. Sob sob. For now, I'll either get a cheap and cheerful motorcycle or spend even less by taking bus and mrt. Sadly, for a small country, our public transport is not fast enough to catch up with the country's fast paced lifestyle. So, I present to you 2 simple steps to minimize the pain in taking public transport in Singapore.

1. Make technology work for you! Minimize your dwell time at bus stops.

It sucks to arrive at your bus stop only to see your bus leave just before you can run. Now, you can know what time these buses arrive in advance.

Download the app "SG Nextbus" on your smartphone to find out how long it takes for your bus to arrive. Especially useful if you live quite a distance from your nearest bus stop because you can pick up the pace if you know that a bus is arriving soon. Better than strolling most of the way and pulling a Usain Bolt near the bus stop. Or better yet, don't even leave your house until the time is right. Bus stops are the worst places to dwell in.

2. Make use of distance fares! Minimize your dwell time at bus stops (again)

Shit happens once in a while. You arrive at your bus stop and the bus you are waiting for is taking eternity to arrive. We all know that shitty feeling.

Well, you could either wait till your bus arrive (chances are, that elusive bus is going to be very packed by the time it arrives) or you could hop on another bus that takes you in the general direction of your destination. Chances are, there will be several buses that go the same way for the first couple kilometers. Get moving and alight at a bus stop as far as your bus takes you in the direction of your intended travel. Chances are, you will end up at a bus stop with other buses available that can possibly take you to your destination. By moving forward, you also open up the possibility of overtaking buses that can take you to your destination. When that happens, alight, hop on your intended bus and smile. There were several times when my next alternate bus arrives in less than 5 mins after alighting.

Its nice to know that we are no longer penalized for bus transfers (up to 5 transfers).



Well, these are the two methods I use for myself and I found them quite useful at reducing the time I wait for buses. I used to drive to school but now that I have graduated and jobless, my brothers now have priority over the family car and I have to use public transport most of the time. Truth be told, I really hate public transport. Buses are slow and unreliable and trains are often packed. In other countries, taking public transport is only a phase in life, in Singapore it is likely to be something people will be doing for life. I wish I could do something with public transport in Singapore but since I probably can't, these are the little things I do to make my own transportation less of a chore. I hope you find them useful and if you have any methods to share with me, do tell me too!

Different typs of batteries and which to choose

When was the last time you had to deal with batteries? Chances are, the batteries that you'll have to deal with are rechargeable batteries that are built into your phone or removable camera batteries. Manufacturers of tech gadgets are increasingly building their power sources inside the gadget or have their own removal battery design. They do this partially to make sure that the power source is reliable and suitable for the gadget's power requirement and partially to make sure that you have to go back to them to purchase batteries.

There are also some companies that leave it to the consumer to use replaceable consumer batteries. For these, it is important to choose the correct battery type such that your equipment works in the best possible way and to reduce unnecessary costs. There are many websites that you can read up on to know about battery choices. But they are usually rather technical and they assume that you have some basic physics knowledge.

A very comprehensive write up. Very long also - http://batteryuniversity.com
A simple table comparing common battery types - http://michaelbluejay.com/batteries/
A collection of battery/electronics guides. Also with an awesome database of battery capacity, characteristics of many brands and models - http://www.candlepowerforums.com/vb/showthread.php?133440-Flashlight-Electronics-Batteries-Included-Threads-of-Interest

First things first. There is no such thing as "the best battery" for everything unless you don't mind spending on the most expensive batteries and not using them to their max potential. I'll start from the most expensive to the cheapest non-rechargeable followed by rechargeable batteries

Non-rechargeables

1. Lithium

Dominated by Energizer, this type of battery has the best performance amongst other non-rechargeable for high drain devices. They are have extreme long term reliability and wide temperature tolerance. Downside is, they are damn expensive and costs as much as rechargeable batteries.

Best for: Devices that are expected to use up batteries within hours or less (cameras, video cameras, flash units, high power torch lights). Since they are so expensive, it makes sense to use them as backup batteries when your rechargeables are drained. Otherwise, use them for devices that you are likely to depend your life on. Coin size lithium batteries are also used in watches.

Price: About $5-7 a piece for AA and AAA in NTUC.

2. Alkaline

Offered by several brands. Cheaper brands are likely to have lower capacity. For example, I bought a pack of 10 AA batteries from IKEA at $2.50. According to tests done by forumers of candlepowerforums, they do have significantly less capacity than Energizer ones. But that is ok since they are so cheap! Long time ago, battery powered devices use very little power and alkalines were amazing. But now, with gadgets becoming smaller and requiring higher power, alkalines have not caught up with the demands of current day consumer electronics. Although they are supposed to have comparable or even more energy than Lithium batteries, their capacity decreases proportionally to how fast you drain it. Alkalines become less and less value for money the faster you drain them. Using them to power digital cameras is just a spectacular waste of money. However, they do have the tendency of leaking after keeping for a long time and may corrode the metal parts of your stuff.

Best for: Devices that run intermittently and have really low current requirements. Things like remote controls, clocks, radios, and stuff that are expected to last for weeks and months (or more than ~10hours of continuous use) on a single set of batteries. This is the only way to make full use of the high capacity. However, don't put them in devices that you may forget about.. because they may leak and destroy it.

Price: About $1-2 a piece for AA and AAA usually. Cheaper brands are fine since you are using them for low power and non-critical devices.

3. Carbon Zinc

Usually marketed as "Extra heavy duty" batteries. This is one of the oldest type of battery available and also used to serve devices of its time. In the 21st century, carbon zinc is super light duty! Again, they are suitable for devices that are suitable for alkalines, except that they have lower capacity then them. The only reason why I have Carbon Zinc batteries in my possession is because they came with things I bought. They are a good alternative for alkaline for bigger sized batteries such as the C and D size if you don't want to pay for an alkaline equivalent. But then again, I rarely have any devices that use such large batteries anymore. Maybe boomboxes? Who uses them now anyway? Do you even know what they are? Gosh, I am old.

Price: Depends on the shop selling them. They are supposed to be very cheap. I don't have any prices for reference.

Rechargeables

A. NiMH types
These are commonly available. The capacity goes up to about ~2500mAh for AA size but don't always believe what the label says. Most companies have the tendency to lie about their rated capacity and their batteries almost never achieve the claimed capacity. Until one day, a company decided to be honest about their rated capacity. Till now, Sanyo is the only company that is truthful about their battery capacity. Their "Eneloops" line of low self discharge batteries (meaning that you can charge them up and leave the batteries alone for a year or more and they will still retain a significant portion of the charge. The change in design brought about more than just low self discharge, but also a more resilient battery that lasts significantly more charge cycles than other brands (1500 cycles compared to the usual 500 cycles). To me, that is quite an improvement because their batteries cost the same as other brands and yet they offer so much more. Forumers from candlepowerforums swear by it.

Best for: This is probably the most versatile battery chemistry. Unlike alkalines or carbon zinc, this chemistry can take repeated high power usage without much loss in usable capacity, making them a good choice for cameras and high power torch lights. Although this is very good, they still need proper care in order to achieve their longevity and performance. Be sure not to drain the batteries completely by recharging them once you know they are getting weak and invest in a good charger that can sense when the batteries are full. Avoid 15min fast chargers. And no, there is no need to insist on draining it very low before charging it.

Price: about $5 a piece (AA)

B. Lithium-ion


These batteries are usually found in laptops, handphones and electric vehicles because they have the highest energy density, which allows them to store a lot of energy without being too heavy. These are not sold in its basic form, but rather, they are sold as battery packs and internal batteries because they require more care than NiMH batteries. They may explode if treated improperly, hence, most consumer products have safeguards in place to minimize the chance of this happening.

To take care of this battery type, try not to drain it too low. Once your computer or phone reaches 20%, try to charge it up already. Don't wait till reaches 5% or lower. This is called "deep discharge" and it is really bad for the battery. These batteries are supposed to last 300-500 cycles if you take care to minimize the number of times the battery undergo deep discharges.

In general, rechargeable batteries make a lot more sense than non-rechargeables because they perform well and can be charged so many times that it more than makes up for the higher initial cost. However, they need to be taken care of. The user must know how to treat it in order to reap the benefits.

How to get a lot more from your portable mobile charger

Again, I'm writing about portable chargers for handphones... Having a phone that uses up its internal battery fast is such an inspiration for finding new methods or products that help extend the life of its internal battery.

So far, I've always been plugging in my iphone into my portable charger only when the phone is about to be dead. That is probably how everyone uses their portable charger, no doubt. But the problem is, using a battery to charge another battery is just a waste of energy because of all the loses involved. Try touching your phone when its charging. It gets warm, doesn't it? This heat produced is due to all the inefficiencies in the circuits.

So, to get the most out of your portable charger, stop it from charging the phone battery if possible - make your phone run directly from the portable charger. If its not possible, especially when you use an iphone, there is a solution. However, this method needs planning and foresight. Instead of plugging in your portable charger when your phone is almost dead, plug it in when your phone has 100% charge. This way, the phone will not use the energy from the portable charger to charge the internal battery, but will simply run the phone off the portable charger.

I tried this and got bored since my portable charger didn't cut off after a long while of watching youtube videos, surfing 9gag and chatting. The only drawback was that it was awkward operating my phone with the portable charger stuck to it. This will work best if your portable charger is designed as a protective case. Something like this.

A movie of 3 idiots

Watched a bollywood film named "3 idiots" while on a bus back to Singapore. I was initially put off by the title but after hearing a few friends speak highly of that movie, I had to watch it for myself. The movie revolves around a prestigious engineering college in India which is ran by a obnoxious principal who believed in very strict rote learning, scoffed at any form of creativity and had little empathy for failure. In short, he was the principal that everyone loved to hate. Then, in came a bright freshman who was at odds with such a mindless education system, displayed his rebellion towards the principal and his school while, at the same time, being the top student. This student then, in the course of chasing the principal's daughter, ended up indirectly convincing the principal that education need not be so rigid and life need not be such a cold and harsh rat race.

What I wrote doesn't even come close to justifying how good the movie is and its critique of the Asian expectation of 望子成龙, 望女成凤 mentality and our tendency of minding how other think of others think of our own children if they chose an unconventional career path or if they simply didn't do well in school. In a way, children can be a huge source of pride or shame for parents. I can kind of relate to the film because my parents somewhat falls in the same category of people that the film portrayed. I really liked the scene where *spoiler alert* Farhan said to his dad when he told him that he wanted to be a wildlife photographer instead of an engineer, which was what his father had hoped for him since Farhan's birth. His dad, who was infuriated when Farhan confessed that he skipped a job interview to be an engineer, told Farhan that he was concerned about how his colleague (I presume) would think of Farhan if he knew that Farhan was going to be a photographer instead of a well paid engineer. Farhan, sobbingly replied that he didn't care of what his dad's colleague thought of him because he didn't raise him and he didn't sacrifice to provide him with the comfort that saw him through his college days, Farhan affirmed that it was his dad's feelings that he cared about and hoped that he would understand his choice. *spoiler end*

Well, go watch it.  (:

Finally, the Higgs Boson.

After such a long time and so much effort spent on searching for the elusive Higgs Boson, the good people of CERN has finally managed to isolate this hard to find particle. As a physics person, I am really glad that we are one step closer to knowing more about our universe. This is because, at this point of time, the most coherent way of explaining our world is though The Standard Model. This model is a collection of knowledge that had been acquired throughout many many years of scientific endeavor. Admittedly, there is still some things that are not accounted for but hey, its work in progress.

The standard model attempts to link all the known fundamental forces (electromagnetic, weak, strong) by reducing their interaction into an exchange of particles. Its been very successful except that it does not account for mass. Everyone knows the concept of mass and gravity. We feel it everyday but it is still very mysterious because we don't know what causes it? Issac Newton found out how gravity worked and was able to make predictions of how stellar objects move, Einstein improved it and explained that mass causes the bending of space-time, sucking everything towards itself. Peter Higgs, the guy who suggested the existence of the Higgs boson, found inconsistencies in the Standard Model that may be fixed by the addition of gauge bosons. In layman terms, why the hell doesn't light have mass? Why do massy particles even have mass in the first place? So, the Higgs Boson is the particle which is kind of responsible for mass in the theory of The Standard Model. If the Higgs Boson could not be found, then it means that what we think we know about anything with mass could be VERY WRONG. So, yay!

The Higgs boson, which is predicted to be "very massive" in terms of energy, meant that a lot of energy has to be used to create it, which is why CERN's particle accelerators span several countries. Their accelerators accelerate charged particles in opposite directions and make them slam into each other as they meet on the other side of the circular loop. slamming extremely energetic particles together will result in an explosion that creates new particles from the energy of the initial colliding particles. Most particles created are those that we already know. Some of these particles are extremely unstable while they are in isolated while some interact very weakly. These two issues pose a problem for detection and thus it is a pain in the ass to identify them.

The Higgs Boson goes a long way towards validating the our current knowledge of our world in terms of the Standard Model theory and gives us more room to expanding into the unknown. On this weighty subject, it is time to log off and prepare for my Vietnamese test!

Tampines Bike Park

A recent visit to Tampines Bike Park had me wondering why did it take so long for me to visit that biking trail. Well, it sucks to live so far from such an awesome bike park. I live in the northern part of Singapore and it is really exhausting to cycle from where I live to Tampines. If I tried, I would be too tired even before I got off road.

How to get there:
If you search for "tampines bike park" on google maps, you will not find it. The location pins are nowhere near the place. It is along tampines ave 9, at the junction of tampines ave 7. On google maps in satellite view, you would be able to see the brown meandering trails set upon the untouched patches of green, surrounded by construction sites and HDB flats. Thats it!

When I was at the entrance, I thought it was some closed up area and I was tempted to believing that the actual trail is the small rocky part on the right on the entrance. But I was entirely wrong. I think most people would have the same thinking since the mountain biking scene in Singapore isn't really developed and no one would expect a nice gated entrance to a bike trail. Especially so when Mandai's Track 15 requires one to crawl under a gate with a keep-off sign.

Upon entering, there is a sign in/out booth which reminds me of guard duty during my army days.

What facilities are there:
Normally, bike trails have 0 amenities. You get there, you ride, you get out. But this bike park left me very surprised. There are quite a few porta toilets, a big parking area that is free and the best part is, they have a place to wash our bikes! The only place that has these 3 facilties that I know of are golf courses. These are places where people pay shit loads of money to enter, but this bike park is completely free. I have no idea who is paying for all these, but I hope it lasts!

The ride:
 If you have ridden in Pulau Ubin's Ketam Bike Park, you will be in familar grounds. There are many routes to take and they are clearly demarcated according to their difficulty levels. My friend fell at a blue square grade trail for beginners. Clearly, it is not a walk in a park.

There is also a separate area for bike trials. The route looked really awesome with all the humps and curves. Would love to ride through the course if only my front brake cable didn't went loose when I was there.

What to look for in an everyday-carry (edc) torch light?

As a battery and torchlight enthusiast, I believe that everyone should carry some sort of light with them, EVERYDAY. No, it does not need to be super bright or super chunky. Just a small reliable light that works when you need it to. I rarely get the chance to use my trusty LRI Photon III but when have to, I'm really glad that I have it with me. Two years ago, my friend and I had to walk through a short unlit underpass in Orchard area. Having my light on my keychain means that it is extremely easy to find and it allowed us to see about 1-2 metres in front of us. We couldn't see that much because we entered the underpass from inside a brightly lit building and our eyes needed time to adjust to the sudden darkness. But still, my trusty little keychain light is enough to guide us through the steps and emerge on the other side of the road. In this situation, we only needed the light for about 1 minute or so. But that 1 minute of light reduced a potentially clumsy situation into a simple stroll.

My broken at tattered blue Photon III

My dad bought this for me when he traveled to the US many years ago on a business trip and it has been on my keychain since. Fortunately or unfortunately, in Singapore, the country where I live in, blackouts are extremely rare and street lamps are virtually everywhere. But that doesn't mean that we should be complacent and not have a torch light with us! Well, if you have a smartphone, chances are, it has an LED light that works as a flash for the in-built camera and it can double up as a torch light. Given the battery that most cellphones use, the in-built LED light will probably be brighter than most keychain lights. However, turning the light on does drain the battery a lot faster than normal. So, why not bring along an EDC light?

What qualities should we look for in an EDC light? In short, I think something like Photon III makes a very good EDC light.

1) Compact and light: Being small means that it is easy to carry around and it will always be with you whenever you need it. For the smallest form factor, lights that use coin sized batteries offer the smallest package while (usually) giving decent runtime

2) Reliability: Just like an insurance policy, and EDC light is rarely used but it needs to be relied upon whenever the situation requires. Lights with low maintenance are necessary. In this case, the battery plays a very huge role since most LED torch lights do not need much care. Use only lithium batteries as they do not leak, have an extremely long shelf life of 10 years (some forumers say 20 years). Most coin sized batteries are either lithium or alkaline types (not interchangable and their sizes differ). So choose one that can accept lithium.

3) Lock out or auto-off function: A light that is moved around all the time has the possibility of having it turned on accidentally. To prevent this from happening, some brands adopt either methods to prevent the light from draining the battery accidentally.

An EDC light need not be very bright or last for many many hours on a single set of batteries. Anything with a simple 5mm nichia led will do just fine because sometimes a little light is all that is necessary to change a potentially dangerous situation into a minor inconvenience.

I hope this little write up can help you choose your EDC light  :)

A review of my dad's emergency iphone battery charger (SKU18197)

Finally decided to do a little review on my "emergency" iphone charger.

Iphone users know how often "emergencies" crop up when they forget to recharge their phone up the night before. You know your battery isn't going to survive till the end of a long day when you leave your house in the morning with 60% charge or less, especially so when the phone serves up many different purposes in 1 single day. I find that the need for a portable charger arises most often when I am heading out with my friends for a day packed with activities. A day like this will mean that I won't be coming across any free power sockets, and even if I do, I probably won't be in one place long enough to get a substantial charge. So, this is where my "emergency" charger comes in.

In simple terms, an "emergency" charger is a battery encased with a circuit board and a connector that charges the internal battery of a phone, nothing more. At this point in time, I have two of these little critters. One handed down from my dad. Typically, these chargers contain a Lithium-polymer battery, the same type of battery that is inside an iphone. This type of battery have the highest charge density and adequate performance to provide substantial energy to your phone. To me, it is the best battery type for the job because other battery types such as Alkaline, Carbon Zinc or even Ni-MH rechargables just do not have the juice to give an iphone a good charge. Sure, carrying more of these batteries will mean more charge but it is worth the trouble?

So, here's mine. It looks suspiciously like SKU18197 from dealextreme except that the battery capacity is a little different.

Polished metal top surface. The button on the right is for checking the amount of charge left.

It says 1900mAh at the back but it is not going to be easy to verify.

The front portion has a protruding connector for charging the iphone.

While the back port is for recharging the unit. Entirely compatible with the original USB charging cable. 

The blue indicator leds light up when charging. It fits quite well despite having a protective silicon cover in the way. Also, the connector fits well despite being a non-official iphone product - it is not too loose and it feels quite sturdy. I feel confident enough to put it in my bag and let it do its business. It does get slightly warm when charging and does not produce a high pitch inductor whine (common for cheaply designed circuits).

So how fast does it charge?

To test this charger, I set the alarm for every 15 mins (except the last reading which is 10mins away) to check its progress while it is charging. The wifi is turned off while 3G and cellular data is left on to reflect typical "standby" drain from the iphone. My phone's initial charge is 38% and I ended my test with 83% - an increase of 45% charge. As this is to test the charging speed, I did not completely drain the emergency charger. Typically, it gives me about 50% plus and minus 5% depending on my phone usage. The charging speed is fairly constant, providing an addition of 10% charge for every 15mins. This is consistent with the fact that the iphone can be set to charge up at constant rate (possibly USB charging current of 500mA), which is about half the charging speed from using the original wall charger.

Overall, I think the charging speed is sufficient. Moreover, the faster the emergency charger charges the iphone, the more strain it puts on the battery, resulting in more heat, less usable capacity and lower number of charge cycles. These are physical limitations that must be considered during the design to give the maximum battery boost to the iphone given the limited capacity and the small size of the emergency charger.