Feb 252016
 
A solar cell on the top, and an array of LEDs on the bottom, and a rechargeable batter inside make up the Deckey Solar Light.

A solar cell on the top, a motion sensor and array of LEDs on the bottom, and a rechargeable battery inside make up the Deckey Solar Light.

As travelers, we spend appreciable time away from our home, and an unoccupied home is an appealing target for burglars.

There’s very little we can do to make our homes impregnable.  We can harden them somewhat, but that’s all.  We could add surveillance systems that may aid in the subsequent identification and prosecution of burglars, and modern camera systems can even give us the added frisson of participation in our own burglary by being able to watch it, real-time and live, over the internet on our phone as it happens.

We can add interior lights on timers that semi-randomly go on and off; even radios or televisions too, to try and create the appearance of someone living in our home.  But an experienced criminal will spot other telltale signs – curtains that remain unchanged, unclaimed packages on our doorstep, trash bins that don’t go out or come in, and so on.

There’s one other small thing we can do, both as another boost to security and also for our personal convenience while at home.  We can add some sensor-activated outside lights.  Many criminals are nocturnal, and fear the light.  Shine a light on them, and they scurry away again.

Modern advances in sensor technologies, photo-electric panels, batteries and LED lights, have revolutionized the traditional ‘outside light’.  It is now possible to realistically place lights around your property, more or less wherever you wish, and not to need to worry about running power to them.  That’s a tremendously liberating freedom that opens up many new places where it would be nice to put a light.

Higher efficiency photo-electric cells, higher capacity/lower cost rechargeable batteries, and wonderfully efficient everlasting bright LEDs that give out huge amounts of power while requiring only a trickle of power all make for truly functional and useful stand-alone lights.  Wrap that all together with lower and lower costs, and you can now get good units for as little as $25.

I was asked to review one such $25 unit, the Deckey Wall Light.  Although I have some outside lights, they are hard-wired ones and I only turn them on when I’m expecting a visitor, and I hate the hassle of having to clamber up a ladder to reach and replace the bulbs every few years.

So I happily agreed to try one out (as witness this review now).

The unit arrived in a nice enough cardboard box.  There was the unit itself, plus a set of mounting screws and a ‘pokey thingy’, and a brief set of instructions in somewhat opaque ‘Chinglish’, and a mounting template.

Not stated anywhere, but something I’d recommend, is removing the protective clear film from over the photo-electric cell.  I expect the film absorbs some amount of light energy, while adding no value in exchange, so peel it off.

I unscrewed the battery cover to see inside, and was greeted by a generic rechargeable 18650 Lithium-ion battery – the most common and economical type of Li-ion battery, and the same sort that powers Tesla cars.  If it should ever need replacing, you can do so as easily as replacing an AA battery in any other type of appliance – just pop it out of its holder and pop in a replacement (they can be purchased for $5 or so on Amazon and elsewhere). I measured a 3.76V charge on it so presumably the battery had been reasonably pre-charged at the factory, which was nice.

The unit comes switched off, of course.  You can either press the on-off switch after removing the battery cover plate, or use the ‘pokey thingy’ – something a bit like an unfolded paperclip, such as comes with iPhones – to reach in the access hole and press it on and off without needing to remove the battery cover plate.

The unit was not at all heavy and made of plastic rather than metal.  It was so light that I didn’t bother with the two mounting screws.  I simply used a piece of tape to affix it to the smooth surface of my guttering, so mounting it was tremendously simple.

The unit is rated at providing 440 lumens of light.  In comparison, a regular 60W light bulb provides about 800 lumens of brightness, so it gives a bit more than half the ‘light’ of a 60W bulb.  But because the light is in one direction, its ‘focused’ light is more closely comparable with the omnidirectional light of an incandescent bulb.

The light comes from a grid of 20 LEDs, and there’s a diffuser over them to soften the light and not dazzle you from a series of single bright point sources.

The unit is said to be IP-65 water resistant, so you don’t have to worry if it is exposed to rain or snow.

The Unit in Operation

Easy.  During the day it does nothing, while the photo-electric cell quietly converts sunlight into electricity, which is stored in the Li-ion battery.  When the sun sets and night falls, the unit automatically switches into low power operating mode, and sends out a dim glimmer of light that reaches out a small way around it.

When the unit’s built-in IR sensor detects something moving, it then switches to full power for the period of time it detects movement and some extra time subsequently, before then lapsing back to low power mode.

Then the next morning, the sun rises, and the unit returns to charging mode again.

I noticed a couple of differences between its claimed performance and its actual performance, one good and one not quite so good.

The good variation was the sensitivity of the IR detector.  It is rated to be sensitive to movement out to 10 ft (3 meters), but it would readily detect small movements on my part, 15 ft away.  That gives you more flexibility about where you locate the unit and more ‘radius’ within which it will come on.

On the other hand, sensitivity is an issue that needs some compromise.  Too sensitive and the unit will come on due to ‘false alarms’ and small animals, too insensitive and it never comes on at all.  I’ll not argue against a 10′ – 15′ range of sensitivity as being a good compromise area.

My dog kindly agreed to test the unit as well, and it would trigger from almost as far away when she moved in and out of the sensor’s range.

The not quite so good difference – it is stated to have a 30 second timer, so that the unit stays on for 30 seconds after movement is no longer detected.  I timed it in the 12 – 13 second range, never anything like 30 seconds.

This, like sensitivity, is also a double edged sword.  If the delay period is too short, then the light flickers on and off too much; if it is too long, then you’re using up too much charge after the reason for the light turning on has ended.  Again, I’m not going to take sides on this, and will merely observe that its ‘dwell’ time was only about half the stated 30 seconds.

Is the Photo-Electric Cell Powerful Enough?

Does the unit take in enough charge each day from the sun to operate each night?  As best I can tell, the answer appears to be ‘yes’, although this is very dependent on how much time each night the unit is operating in high-power rather than standby mode.  I’ve been using my unit now for five nights, and in a shaded occluded part of Seattle in mid winter – hard to think of a worse case scenario for getting as little solar power during the day to recharge than that!

Actually, my use-case scenario is even worse.  The solar panel is angled towards the northwest and is blocked from the south, meaning that very little light ever falls directly on the cells.

Wherever possible, you should try to have the solar cells facing as directly south as possible (if you’re in the northern hemisphere) so as to get the best exposure to direct solar energy.  But in my case, with only an hour or two at the end of the day where the sun shines obliquely from a westerly direction and catches the solar panel, that still seems to be enough to maintain sufficient charge for the night’s operation.

The Li-ion battery seems to have a reasonably good capacity (2200 mAh) so it can store up enough charge for a couple of days of operation should the sun fail to appear at all for several days in a row.

Is the Light Bright Enough?

Well, if you’re like me, there’s no such thing as a ‘too bright’ light, particularly for security purposes.  But if you’re not actually wanting to instantly blind your innocent visitors with a light equivalent to that of ‘a thousand suns’, then applying a more reasonable measure, the answer is ‘sort of’.

Could you use it to read a newspaper column at 10 yards?  Absolutely not.  But could you use it to safely see your way across a driveway, and avoid obstacles that might otherwise have been in your path?  Within a similar sort of radius, and for a semi-circle around the unit, yes.

These are intended as supplemental area lights, not as higher intensity local task lights.  Will a single one of these cause a determined burglar to run away?  Probably no, not at all (especially with their shorter than advertised dwell time).  But that introduces the next consideration.  Why get only one?  They’re only $25 each.  Why not get half a dozen, and line your driveway or house exterior with them, one every 10 – 15 ft?

When the unit is on standby, the LEDs give off a dim glow, a bit like weak moonlight, for a small area around the unit.  But, in standby mode, they don’t need to be full on, because there is nothing around that ‘needs’ the light.  Instead, the standby lighting acts as a sort of distant beacon so you know where to head towards in order to then trigger, at about 15 ft, the full powered lighting.

Summary

Tremendously easy to install, and expected to give years of no-maintenance operation once mounted, these are affordable and effective lights to ring around the perimeter of your house, to add to pathways, and so on.  Available on Amazon for $24.99

  One Response to “Solar Powered Outside Light for Security and General Convenience”

  1. […] written a couple of recent articles about solar powered outside lights and portable LED lights suitable for traveling with.  But the as yet unanswered question is […]

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