Runtime of Primaries Vs. Rechargeables

nitebrite

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There are calculators on the internet where you plug in the load ma and the battery capacity mah. I was wondering if this would differ between Primaries and rechargeable. Or if it is constant. For instance a 1550mah 123A VS a Samsung 35E? Assuming both are discharged at 3.5 Amps constant. I would think the 35E would perform much better but I have heard people say the 123A ran longer? This is what I do not understand. I was hoping someone could explain this. I am guessing it has to do with the difference in chemistry. Thank you
 

archimedes

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The different chemistries have different voltages, and different discharge curves, and those curves vary under different loads ... so, difficult to generalize.
 

nitebrite

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Thank you. That is what I figured. So that is how a 1550mah battery runs longer than a 3500mah battery. Of course it only runs once and sacrifices itself. The 35E can run over 500 times :) Obviously they have different applications.
 

nitebrite

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Yes, I sort of mentioned like a 21700 would be 2x 123A in Series but that would still be the 1550mah. It is series not parallel. The strange thing if you look at specs on boxes of lights often times the 2x 123A have longer runtime than the single 50E. I know I mistakenly typed 35E which is an 18650. They utilize a sleeve when they implement this. I guess I will just stick with the 50E. Eating up 123A to get 1/2 hour more is way too expensive. I can just carry spares in the field and a little light to change them. My luck that is just when a bear will show up. I mainly use the Dominator anyways. It is just that now they have lights that throw twice as far. Some are 18650 and some are 21700. Regardless 123A is not very cost effective for me. It is really for someone that needs shelf life. So you wonder why I asked the question? I was curious about the mathematical conversion. That is all. I think it is okay to learn. On that front, Thank you guy's for answering the question!
 

WalkIntoTheLight

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The only situation I would recommend CR123's over a lithium-ion (18650 or 21700) is in extreme cold. Below -20C, lithium-ion really struggles. Lithium primaries will still work down to -40C. Other than that, stick with rechargeables. They perform better, have more energy, and are way cheaper in the long run. An 18650 or 21700 can sit on a shelf for years and lose very little capacity, so shelf-life isn't really a valid reason to choose CR123 either.
 

nitebrite

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Thank you. Plus if the LI-ION has LSD it will hardly self discharge in any reasonable time. I try to get cells with LSD. A good 5000mah 21700 with LSD will be at 90% in almost a year of non use. Of course these are not going to be the big brands but rather specialty brands. For instance KeepPower. I keep 18350 Keeppower cells in my pocket lights such as Hanko or Deadwood that I do not want to charge often. They have LSD. I check them in a year and they did not lose much at all. I feel that because of this feature, 123A is just a money gobbler. Unless 20 below zero which does happen here so than I do require them. Like in my weather station, outside 24/7. Otherwise 123A cannot pull the current or mah of big LI-ION cells AFAIK. I was not sure if in some instances they could surpass them. Someone said their UDR Dominator runs longer on 123a's. even if it does, I cannot afford that in mine. That is an entire box of batteries.
 

WalkIntoTheLight

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Keeppower is just a re-wrapper that adds a protection circuit and button-top. Unless you need that, stick with the real manufacturers like Panasonic, Sanyo, etc. I have some Keeppower cells, and while they're decent, I'm really not that impressed with their performance or capacity. I don't know what cell they used under the wrap, but I suspect they change it based on availability. I've always been much more impressed with genuine flat-tops like Samsung 30Qs, VTC6's, GA's, etc.
 

chillinn

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I have some Keeppower cells, and while they're decent, I'm really not that impressed with their performance or capacity. I don't know what cell they used under the wrap, but I suspect they change it based on availability.

Wow. What are you impressed with?
These are Sanyo NCR18650GA, and by the test they perform phenomenally even at 5A. The 3400mAh KeepPowers are Panasonic NCR18650B. I think the advantage is that the KeepPower relabels are surely going to be authentic cells underneath, while it is not so difficult to inadvertently buy counterfeit Sanyos and Panasonics.

I really like the high amp KeepPower IMR18650 in 3200mAh and 3500mAh, and the IMR18350 1200mAh cells. No idea what they are, but they perform and last.

I keep primary Surefires around just for emergencies, but I don't run them.
 

aginthelaw

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Unless you can find cr123a at 30 cents each like i did!!! Woohoooo!!! Fist bump [emoji109]🏻
 

bigburly912

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Someone said their UDR Dominator runs longer on 123a's. even if it does, I cannot afford that in mine. That is an entire box of batteries.

Problem is the UDR dominator only has around a 2500mah proprietary battery. For 1000 bucks they should have done a little better.
 

WalkIntoTheLight

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I think the advantage is that the KeepPower relabels are surely going to be authentic cells underneath, while it is not so difficult to inadvertently buy counterfeit Sanyos and Panasonics.

Maybe. Or, there may be even more profit from faking Keeppower, since they can sell at a higher price. I just buy my cells from dealers I trust, like illum. Then I run some basic tests for capacity and power, just to make sure.

IMO, I wouldn't buy either the manufactuer's flat-top cells, or a re-wrapper, on places like ebay or amazon or almost every chinese retailer. Way too high a chance to get fakes. Probably a lot of fakes in local vape shops, too.
 

nitebrite

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This is very interesting to me. I have a one of a kind pocket light made for me by Rey. He included a card " I recommend use only keeppower battery". It is an 18350. It is the only 18350 that claims drain 10 amps continuous and 15 burst. Since this light draws 9 amps continuous on turbo. I have ran it a lot and no explosion yet. Fingers crossed :)

As far as 18650 or 21700 I feel that Samsung LI-Ions pack the best punch. It is not just the mah under these loads. Although I guess the likes of the Dominator do not draw much current if they even run on 123A's. However, I wonder if it's lumens go down then? Not a big deal anyway as lumens is not what that light is about. The problem with that is even though it runs longer, I kill $60 of batteries. I guess it may suit some first responders.
 

nitebrite

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I was a bit confused. If the UDR Dominator runs 2 sets of 123A's in parallel that is less mah than it's battery pack? Yet it runs much longer? Also the Dominator beats it's posted throw spec but falls way short of it's lumen spec. That is par for the course on a CBT 90 though. Most likely why the 123A's last so long. It is not pulling many amps. I think it has more to do with the chemistry of the battery. I am curious because this would apply to other lights that do not draw much amperage. They would be good to keep for instance in a low power Innova Vampire.
 

nitebrite

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Even though I may not understand it increasing runtime. I do understand one thing. Some less than savory individuals selling batteries. IE: This battery will make your light brighter. LED lights are regulated. It is honestly "This battery will make your vaporizer hit harder" that you see. Those are regulated as well. Except for the old mechanical ones akin to incandescent flashlights. Long gone. I mainly see a lot of that in Vaping where people can be clueless. We tend to know some more about this. I do not mean to insult them. I am sorry that they may be taken advantage of. A junk Chinese cell is never good. However A Panasonic cell will not make any good modern light brighter than a Samsung cell for instance. One may run longer though. I just figured I would point out what I DO know :) I am guessing that this thread is dead now and there will be no further replies. That is okay I have received a lot of good information from you all. Thank you
 

WalkIntoTheLight

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Even though I may not understand it increasing runtime. I do understand one thing. Some less than savory individuals selling batteries. IE: This battery will make your light brighter. LED lights are regulated. It is honestly "This battery will make your vaporizer hit harder" that you see. Those are regulated as well. Except for the old mechanical ones akin to incandescent flashlights. Long gone. I mainly see a lot of that in Vaping where people can be clueless. We tend to know some more about this. I do not mean to insult them. I am sorry that they may be taken advantage of. A junk Chinese cell is never good. However A Panasonic cell will not make any good modern light brighter than a Samsung cell for instance. One may run longer though. I just figured I would point out what I DO know :) I am guessing that this thread is dead now and there will be no further replies. That is okay I have received a lot of good information from you all. Thank you


Most high-output budget lights use FET drivers. Those are absolutely not regulated. A high-drain battery can double the brightness of a FET-driven light, compared to a low-drain cell. As a result, the high-drain cell will have a much lower run-time, compared to a low-drain cell.
 

HKJ

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Unregulated lights often has a very long runtime with primary batteries due to the gradually decreased brightness. Rechargeable batteries often has a much faster voltage drop off when they are empty and due to the typically lower internal resistance the light may be brighter for most of the time (Sometimes a primary may be brighter initially).

There are a lot of interactions between drivers and battery chemistries that defines brightness and runtime.
 

nitebrite

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Wow, I thought this thread was done. No guy's I meant like modern high end Surefire lights and such. If you take out the regulated equation it has to leave battery chemistry is my guess. As I was guessing about 2 stacks of batteries in the Dominator run twice as long I Get the battery pack is 2400 mah but the 2 stacks of 123a's would be 3100 mah at 2.5 amps vs 15 amps. I mentioned mine is only 1900 lumens. I don't know if that is nearly no amperage draw. they run about 90 minutes in an E2D. They run forever in an Innova X5. I just do not understand what dictates where a rechargeable runs longer than a 123A for one cycle. I have seen it in Vaporizers. I have seen kids run an 18650 under hard load for 6 hours but that is intermittent. I am guessing the key factor is battery chemistry. There is no way to tell if a VTC5 will run longer than 2x 123A until you try it. That is my assumption at this point. As far as regulated circuits such as Surefire it will not make them brighter however either way. As you both point out, unregulated circuits will become much brighter. My point was the opposite. Also I do not find that 123A just stop. To me they fade out just like LI-Ion. Perhaps I have great luck. I am not trying to just drag out this thread. I was just pointing out that was not what I was speaking of. I mentioned the brightness solely in regard to people being mislead in a modern era. Most lights are highly regulated by now. As far as brightness goes, no battery shall make a difference so long as it is of decency. At least that is my understanding of things. I am speaking of in a regulated circuit.
 
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