After christmas, I had some giftcard money and was looking for a flashlight to replace my failing Maglite. I saw the Nebo 5620 on Amazon, and for 35 bucks, I thought I might as well give it a try. Its advertised at 310 lumens, and while I highly doubted that claim, there were no reviews to verify it true or untrue. It arrived well packaged in an acrillic container, with batteries in the light itself, an extra set of batteries (3 aaa), and a lanyard. Instead of having to click the button for all the functions, there is a selector wheel on the back of the light, so you may just spin to the selected setting and hit the rubberized, glow in the dark button on the back. It has a 10, 50, and 100 perent setting, along with strobe and SOS. Another funtion is called the "stealth ring", which is a small metal ring on threads that hides a plastic red ring that otherwise glows when the light is on, which is later pictured. The focus, or "zoom" of the flashlight is also quite effective. Fully zoomed,the flashlight illuminates a small area brightly for around 200 yards, and the box says 216. Zoomed out, the light (on 100%) illuminated my entire yard, from the ground to the tops of trees, more dimly of course.The overall construction of the light is surprisingly good. The machining is clean, the threads are even and work well, and feels solid in the hand. Only gripe is the setting adjustment wheel rattles slightly, but it itself if "clicky". Stated battery life is 2 hours on 100%, 5 on 50%, 12 on 10%, and 60 on strobe/SOS. If a person was to weapon mount, it would have to be modified as there is a non removable belt clip attached to the body. Beware, shitty noob iphone pictures ahead. The pictures of the light out in the dark do not do it justice AT ALL, as iphone cameras are not exactly known for their light gathering abilities. I have never done a review before, so go easy.


In package



Extra battteries and lanyard



Out of package


Lens


Stealth ring disengaged


Stealth ring engaged


Setting adjustment ring at back of flashlight


On, off button


Flashlight adjusted to wide illumination


Flashlight adjusted to precise illumination


Light with stealth ring disengaged


Stealth ring engaged


Focused illumination at 100%


Focused illumination at 50%


Focused illumination at 10%


Wide view illumination at 100% (most impressive)

*ANY* LED flashlight that runs on 3AAA batteries is crap, plain and simple.





They usually run direct drive off the batteries, with no regulation
circuitry. LED's need about a minimum of 3.8 volts to run efficiently,
so 3 AAA batteries drive the LED at an initial voltage of about 4.8
volts, and the flashlight looks really bright...


to begin with.





But, under drain, the alkaline batteries lose voltage very quickly, and
within even 30 minutes of run time, they can be putting as little as 50%
of initial lumen output. Triple A batteries just don't contain much
energy.





Three AAA batteries only have a little more capacity than a single AA
cell. There is no way to get around the laws of physics: claimed lumen
output and run times are generally greatly exaggerated. Yes, you might
get 6 or 8 hours of 'runtime', but for all but 1 hour, or less hours,
the LED is putting out very little light.





Alkaline batteries also have internal resistance which is a result of
how the chemical reaction works to produce electricity. Alkaline
batteries work best at low current draw: around 30 to 50 milliamps.
Drawing more current than that greatly overtaxes the battery cell,
resulting in lower lifespan.





This is why almost all of the better, high ourput LED flashlights use 1 or 2 of those
relatively expensive Cr123 lithium cells.



The reason is two fold:
lithium batteries have greatly increased energy density, compare to the
same size alkaline battery. They contain much more energy (electrical
potential) than an alkaline battery. The produce about 3.3 volts when
new, and, unlike alkaline cells, are able to efficiently supply current
up to and exceeding a 1000 milliamp draw, with no loss in battery life.





Also, lithium cells drop much, much less in voltage over their lifespan,
than alkaline batteries do. They start out around 3.3 volts, and when
they are nearly exhausted, they are still producing 2.7 to 2.8 volts.





Even if a flashlight has a halfway decent design, it will ALWAYS be severely limited if it is powered by 3 AAA batteries.