A number of the DX lights are available in 18650 only or multipower (both CR123s and 18650). I realize they require difference circuits. Are there any generalizable findings about comparing these? Which is likely to be brighter? Give longer runtime? What are the advantages and disadvantages of each? Is there a difference between the multipower running 18650 and primaries? Is there a difference between the singlepower 18650 and the multipower running 18650?
Multipower vs. Singlepower
- Thread starter davidra
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Fallingwater
Flashlight Enthusiast
Differences in brightness do not depend on the presence of more than one mode.
The advantage in having more than one level is that whenever you don't require a full-power Beam Of Death, you can use dimmer levels that preserve battery life and don't hurt your night vision, or don't reflect all over the place and blind you when you're trying to work on something.
There are two disadvantages I can see in multimode lights. The first are the ever-present strobe and SOS modes, which can be a pain if you don't need them and the interface isn't designed in such a way that you can avoid them. The second one is that there are some flashlights that have as many as 20 modes, divided in three groups. I don't know about you, but I don't want to have to read a guide and/or fiddle with a flashlight for hours in order to use it.
There are some lights (such as the 18650 U2 Cree clone) that only have two modes, with the dimmer one provided by a resistor in the tailcap. Those tend to be less efficient, but at least they don't bug you with strobe and SOS...
As far as I know, there are no primary lithium 18650 cells.
For more information, please link the flashlights you're interested in.
I'm not talking about modes; in fact, I never used the word mode. I personally don't care about anything other than high or low. I'm asking about differences in performance in lights that can only be powered by 18650 or those that can be powered by either 18650 or 123 primaries.
Like:
This http://www.dealextreme.com/details.dx/sku.8537
versus this: http://www.dealextreme.com/details.dx/sku.8672
Like:
This http://www.dealextreme.com/details.dx/sku.8537
versus this: http://www.dealextreme.com/details.dx/sku.8672
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VidPro
Flashlight Enthusiast
the 2 you listed seem to be same.
but to answer your question, there is some generalities that can be made about the 2 curcuit types that are used.
one that is good for the max 4v (listed as 4.2) and one that is good for the 9v.
but most of the 18650 lights that will take 2x3v batteries ALSO, are the 4-9v style. or the higher voltage driver type.
the lower voltage drivers often fall out of regulation on the high end (boost), the high voltage drivers often fall out of regulation on the low end (buck), WHEN used with a li-ion battery, WHEN the Vf of the led is the usual white high powered led.
I am NOT saying all of them are like this, but a whole load of them are, where your DD at one point or another with the li-ion cells, with slight resistance from the curcuit.
Best to look at the reviews and charts for any of them before purchace, it is likly that any light that will take the 6+v, that is cheap, and will run with a li-ion will fall out of regulation early, and go into a nice declining direct drive similar output. a Buck type of driver
BUT AGAIN, i am not saying that about everything, you asked for wild generalisations, and that generalisation today can often be made, but not always applies.
that usually means that a light that would handle 2x3v batteries will often have a much longer runtime, and a nice declining output when using the 18650, making for a very nice, but barely regulated light, the light can also waste little power when its in direct drive.
are they "multipower" no not usually, they either overdrive or underdrive
they "Work" at that power, so they can be used at that power. only a DC-DC converting buck/boost (both) driver would be fully "multipower" and efficent with multiple input voltages, and very few of them are used or sold comparitivly.
for LED longevity, a person would be better off with the higher voltage drivers, that fall out of regulation at the low end of the li-ion voltage, for high output of light a person would like the low voltage drivers that overdrive when the li-ion is fully charged, the led is getting damaged, but the brightness has the wow factor.
but to answer your question, there is some generalities that can be made about the 2 curcuit types that are used.
one that is good for the max 4v (listed as 4.2) and one that is good for the 9v.
but most of the 18650 lights that will take 2x3v batteries ALSO, are the 4-9v style. or the higher voltage driver type.
the lower voltage drivers often fall out of regulation on the high end (boost), the high voltage drivers often fall out of regulation on the low end (buck), WHEN used with a li-ion battery, WHEN the Vf of the led is the usual white high powered led.
I am NOT saying all of them are like this, but a whole load of them are, where your DD at one point or another with the li-ion cells, with slight resistance from the curcuit.
Best to look at the reviews and charts for any of them before purchace, it is likly that any light that will take the 6+v, that is cheap, and will run with a li-ion will fall out of regulation early, and go into a nice declining direct drive similar output. a Buck type of driver
BUT AGAIN, i am not saying that about everything, you asked for wild generalisations, and that generalisation today can often be made, but not always applies.
that usually means that a light that would handle 2x3v batteries will often have a much longer runtime, and a nice declining output when using the 18650, making for a very nice, but barely regulated light, the light can also waste little power when its in direct drive.
are they "multipower" no not usually, they either overdrive or underdrive
they "Work" at that power, so they can be used at that power. only a DC-DC converting buck/boost (both) driver would be fully "multipower" and efficent with multiple input voltages, and very few of them are used or sold comparitivly.for LED longevity, a person would be better off with the higher voltage drivers, that fall out of regulation at the low end of the li-ion voltage, for high output of light a person would like the low voltage drivers that overdrive when the li-ion is fully charged, the led is getting damaged, but the brightness has the wow factor.
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I think the question is specifically with regard to lights that use the different types of batteries and the general differences in what you can expect, and
I think the two best examples that show the difference would be the Tiablo lights (A8 and A9), and the Deree DBS.
The differences in which batteries would work best lie solely in the driver circuits. The different batteries work at significantly different voltages, so the driver works best with a battery for which it is best optimized for in the voltage range of the battery.
For example, the A8 works it's best with the 18650 even though it can be run with CR123's. However, you can only use the A8's other light level with CR123's if you leave it on for a few minutes and let the voltage bleed down.
On the other hand, the A9 is a perfect CR123 flashlight, but when used with an 18650, it's runtime graph shows a steady decrease in lumens from the moment you turn it on down to 50% (it doesn't regulate well with the 18650 battery even though it can use it).
Then the DBS by Deree is offered with different modules, one that works best on the 18650 (the "digital" module that can be used with ONLY the 18650 because the CR123's will damage it), but they also offer a non-digital module that runs best with CR123's but can also use the 18650.
The bottom line is that (I personally think) you're best off if you decide which battery type you like to run most often, and choose a light that's best optimized for that type.
A light that can use both interchangeably may very well be a compromise in design and not run it's best on either type compared to an optimised driver made for a particular voltage range.
In a very general way, I thinks it's safe to say that either type of battery will give great lumens and runtimes, but only when the circuitry of the light is optimised for that battery type.
I think the two best examples that show the difference would be the Tiablo lights (A8 and A9), and the Deree DBS.
The differences in which batteries would work best lie solely in the driver circuits. The different batteries work at significantly different voltages, so the driver works best with a battery for which it is best optimized for in the voltage range of the battery.
For example, the A8 works it's best with the 18650 even though it can be run with CR123's. However, you can only use the A8's other light level with CR123's if you leave it on for a few minutes and let the voltage bleed down.
On the other hand, the A9 is a perfect CR123 flashlight, but when used with an 18650, it's runtime graph shows a steady decrease in lumens from the moment you turn it on down to 50% (it doesn't regulate well with the 18650 battery even though it can use it).
Then the DBS by Deree is offered with different modules, one that works best on the 18650 (the "digital" module that can be used with ONLY the 18650 because the CR123's will damage it), but they also offer a non-digital module that runs best with CR123's but can also use the 18650.
The bottom line is that (I personally think) you're best off if you decide which battery type you like to run most often, and choose a light that's best optimized for that type.
A light that can use both interchangeably may very well be a compromise in design and not run it's best on either type compared to an optimised driver made for a particular voltage range.
In a very general way, I thinks it's safe to say that either type of battery will give great lumens and runtimes, but only when the circuitry of the light is optimised for that battery type.
