CAUTION !! Misleading budget battery and lumen claims

[timokimm]

amazing helpful info, either way!
now to dig up my own, old laptop battries...

 

[Redhans]

I would consider updating Post #1 of this thread because Panasonic now makes a 3400mAh battery and more than one good company has sold them with protection. Orbtronic sold them protected on their website (now sold out), I think I remember seeing ones protected by Keeppower in pictures.

I also found some German Enerpower+ 3400mAh protected panasonics available NOW as of this post in the ebay store harvestmoonglory for like a bajillion dollars.

Redhans

 

[navarrma]

Is there any demonstrable test that can be used to test the capacity of our new batteries to know whether or not they are reused or just falsely advertised junk?

 

[ElectronGuru]

Without industry standards or government oversight, someone would need to spot check every brand (which hkj is approaching). In the mean time, the the reliable option is not taking the risk (buying from a reliable brand).

 

[The_Driver]

I also found some German Enerpower+ 3400mAh protected panasonics available NOW as of this post in the ebay store harvestmoonglory for like a bajillion dollars.

Hello??? GERMAN batteries, German made things always cost a bazillion dollars

 

[space-cowboy]

NCR18650B is made in Japan
PVC sleeve made in China
PCB ?? - Made in Germany?
Top button?


All those cells are assembled in China, and nothing wrong with it.

Iphone is assembled in China - correct?

 

[The_Driver]

NCR18650B is made in Japan

PVC sleeve made in China
PCB ?? - Made in Germany?
Top button?


All those cells are assembled in China, and nothing wrong with it.

Iphone is assembled in China - correct?

It was meant more as a joke than anything else :thumbsup:

The Enerpower batteries are assembled in Germany. I don't think any of the components are actually made here.
Since they are assembled in Germany and are rather expensive one could assume that the quality of the workmanship especially considering the isolation of the return wire on the outside of the battery should be very good, but only taking apart a cell from them will actually prove this.

Another thing to note: the pcb in the Enerpower 3400mAh batteries allows up to 7A (~2C) discharge, which is basically perfect.

 

[langham]

What kind of lights are you guys using that require such ridiculous power sources? I have always liked the fact that size also adds a little bit of wow factor in the brighter lights. I have conceived making a 100W halogen powered light, but it uses 12 18650 cells and at that power approximately 2.3A discharge from any single battery at a time even dead. That would give me at least an hour even on some crappy 2200mAh cells. The only thing I can conceive using those expensive cells on would be a very nice high powered laptop, and even then it would be a little pricey for my tastes. Good luck with making something that discharges those kinds of amps I have seen some pretty crazy stuff happen when you get too much power out of too small of a package though. One guy exploded his balcony.

 

[Epsilon]

5A of a single cell is very usefull in overdriven xml applications. 7a cutoff is then more than enough, there are cells with 10A cutoffs, which is just not needed. the voltage has dropped to 3v by then.

 

[langham]

The curve for light output vs. current is useless above 3A and just reduces the life of the led dramatically. Why would you do that? The heat dissipation alone would be obscene and call for a light that was at least big enough to house 2*18650. Now an SST-90 could be understandable, but even then the size of the head of a light that uses an SST-90 or multiple XML emitters would be large and bulky and in no way would you save anything by running the light on a single 18650. Beside all of that the smallest 5A driver I have ever seen is very large, much too large to use in any single 18650 host I have seen. If you are talking about running a 4*XML with just 2 18650 cells I would say that is still unwise because in a light that is that bright you don't need to be able to carry it around as your EDC. All in all, just get a multiple cell host and stop trying to spend way too much money on batteries they do wear out after a while no matter how expensive they are.

 

[Epsilon]

@langham I disagree on a few points and will point out why

The curve for light output vs. current is useless above 3A and just reduces the life of the led dramatically. Why would you do that?

This is just not true. With a good LED board you can go way past 3A.
Source: http://www.candlepowerforums.com/vb...racteristics&p=4018726&highlight=#post4018726

The extra 500lumen that a 6A drive deliveres, can be very useful. That you will not find it useful to do, is just your call.

The heat dissipation alone would be obscene and call for a light that was at least big enough to house 2*18650.

For momentary use, almost any host is big enough. Even a 1*18650 P60 is big enough. A good host and thermal management will help a lot. I made a light that runs an XM-L @ 3.85A and can do this for extended times.
Topic with temperature measurements

Now an SST-90 could be understandable, but even then the size of the head of a light that uses an SST-90 or multiple XML emitters would be large and bulky and in no way would you save anything by running the light on a single 18650.

Multi XM-L and SST-90 with the dome is just not comparable with a single XM-L in terms of throw in the same host. The SST-90 is by the way a very difficult LED to direct drive of a single cell because of the relative high Vf. Very little cells go past 5A.

Beside all of that the smallest 5A driver I have ever seen is very large, much too large to use in any single 18650 host I have seen.

True, but single cell operation are mostly limited to X*7135 drivers stacked. Those are small enough.

If you are talking about running a 4*XML with just 2 18650 cells I would say that is still unwise because in a light that is that bright you don't need to be able to carry it around as your EDC.

Too bright? Every application needs a certain amount of light. When my eyes are full adjustment to darkness, the 4 lumen of the low setting of my quark 123 is even too bright. But that just doesn't cut it outside.

There is no "Too bright", only too bright for a certain application. It is imho always desireable to have immense power in EDC size.

All in all, just get a multiple cell host and stop trying to spend way too much money on batteries they do wear out after a while no matter how expensive they are.

This is for everyone to deside. I like high quality and want to pay for it on some occasions.

 

[langham]

You can not seriously think that this data is relative to this discussion of useful data in a real world application. I have 2 XML-T6 leds mounted on 16mm copper heat sinks and they are better than the aluminum heat sinks by a factor of almost 20% at removing the heat from the led. This point I agree on, but the simple fact is that in a single 18650 host the ultimate heat removal process is radiation heat transfer from the body of the light to the atmospheric environment. This test used a large cooler that was regulated at 20C throughout the testing which made the test invalid for any normal flashlight due to the fact that the heat sink used convection types of heat transfer to remove heat from the heat sink. This is completely irrelevant, to the discussion of single 18650 host. My light with a copper heat sink and driven at 3A gets warm to the touch after less than a minute of operation and hot to the touch after only a couple of minutes due to the simple fact of radiation heat transfer from the body to the environment is several times less efficient than the conduction heat transfer from the heat sink to the body. The best heat transfer would actually be obtained by a high carbon content diamond copper board and that would cause the external temperature of the light to go up within seconds to a temperature that was high enough above ambient temperature to make the difference in temperature enough to make up for the difference in efficiency. Another issue would be that the more surface area for heat transfer the light has the more it would be able to make up for the difference in efficiencies. The only thing that having a better material for the heat sink will do is allow you to store more energy per gram of material used prior to the heat being removed by the only real heat sink which is the ambient environment. As far as short term goes, yeah sure you can make a really bright camera flash if you want to but if you mess around and accidentally leave it on or let the wrong person use it you are going to have an expensive paper weight. There are numbers about the different materials used vs the amount of energy they can store, it is irrelevant as well though unless you can ultimately remove the heat externally, which can only be done by either choosing a cold ambient temperature, raising the surface area of the body of the light, making the body out of copper (or some other material that has better thermal properties than aluminum) or by adding some sort of additional flow between the body of the light ( the heat source) and the ambient environment (the heat sink). I guess you could also change the ambient environment to a different material ie: water or some sort of solid, but that would make the light a dive light. The amount of heat dissipation for a given body is set, you can not adjust it short of changing the body in some mechanical form like adding heat dissipation fins and as the amount of watts of heat vs light dramatically goes up after 3A of input current as seen on the provided efficiency chart I do not know how you would account for this factor. Their is 62% more heat being generated based on these charts at 6.5A input vs 3A and that would be an excessive amount considering the thermal capabilities of a single 18650 host.

 

[Epsilon]

The graph of the XM-L is just an example of an application, showing that there are XM-L's which can be driven at above 5A. There will always be a loss in efficiency but that can be acceptable. I could have picked a CBT-90 @ 13.5A, but that is not a realistic application.

You are absolutely correct for long term use. But please, look at my topic with temperature measurements before talking about the dissipation of heat. In short term use, there is no need to dissipate the heat of the LED to the environment, that is the point. There is enough mass in the body to suck up the heat for at least 5 minutes in my example. Which means there is more than enough room to up the power even to 6.5A for short bursts. I decided not to, but it certainly is possible.

Getting rid of the heat in long runs will always be problem in small hosts. The best transfer you can get, is by holding the light in your hand. But also this is limited, I tried to do this with a 9A powered SST-90 in a Mag-D and couldn't stop it to get to hot to hold. But again, this is only for long term use.

 

[Poppy]

Is there any demonstrable test that can be used to test the capacity of our new batteries to know whether or not they are reused or just falsely advertised junk?

bump...
I'd like to know too.

I'd like to buy some 18650s and would like to find some good buys, but if I get one and don't know how to test its capacity, I wouldn't know if it was a good buy, or that I paid less to get less.

 

[langham]

It is relatively simple you can just get on the internet and get the power density for the material used and then weigh the battery, subtract a few grams for the case and protection. That and there are actual battery capacity meters, best bet is to get someone with experience to tell you. The DX SKU: 26248 are very good and relatively accurate in the claimed capacity. I have bought 10 or so and they have all been good. The batteries I currently like the most are the Panasonic NCR18650B or the NCR18650A because of the large capacity and low price.

 

[Travissand]

I have searched but I have not found any one that tested the 18650 TrustFire 4000mAh found on eBay.
I assume the mAh is much less then claimed and will not match eachother in specs therfore would not be suitable for a series device. But I still would love to see all the charts done up on them. Or does curiosity always kill the cat.

 

[langham]

Series would be fine parallel is the time in DC that you would have to worry about the V matching. That link goes to a pair of Panasonic 18650s and they are an extremely good battery.

 

[VidPro]

Re: CAUTION !! When a battery label becomes meaningless

Not sure if this has been posted yet, but i thought it could find a nice home here in Misleading.

A location called taobao, is one location selling your favorite brand battery Wrappers/Label (only) to be able to stuff any cell in about any label
http://item.taobao.com/item.htm?spm=a1z10.3.0.77.saBKb5&id=10193523421&
like here for example you can wrap your batts in a popular panasonic wrapper.
http://item.taobao.com/item.htm?spm=a1z10.3.0.63.saBKb5&id=12670817495&

Just at the one location, they have many different wrappers for turning trash into treasure You can even cap it off with some fake protection.
This just shows how easy has become for some ConArtist to try and rip people off.
Li-Ion or even ni-mh cells.
How does that cell test? better question, what even is it.

When a label becomes meaningless , a reliable trustworthy seller/distributer is the only hope left.

 

[argleargle]

Re: CAUTION !! When a battery label becomes meaningless

Vidpro: there are so many scam alerts in the reviews for cells being sold on Amazon right now that it isn't freaking funny.

Langham: I like it when you post a big fat chunk of text. The bigger the better, the way you write. You sound like you've got a great grasp on heat transfer and dissapation.

...and seriously: if a 4x increase in lumens only means a doubling in perceived brightness, what's with all the splitting hairs concerning an extra 4%-15% in brightness from overdriving the crap out of your electrical system? Just curious. Please discuss and debate.

disclaimer: I've got a few overdriven lights myself.

 

[langham]

Re: CAUTION !! When a battery label becomes meaningless

I know it seems like splitting hairs, but indeed a 12% increase is all you get with the new XM-L2 and that was enough to release an entire new series of light for some manufacturers. The big deal seems like to me it is just in the fact that people want to be able to say that they have the newest and brightest light regardless of its useful functions. I have never over-driven a light, but I do have a plan to build a handheld light that is smaller than the SR-90 and has a force-cooled Cree model emitter and I would simply calculate my turbo mode based on the maximum amount that I could cool the led to maintain temperature less than 100C. I think that people always want to get the best out of what is available at the current time. I have a modified TN-31 that I got during the Christmas deal, and I wouldn't have gotten one otherwise, that stock did not even compare to a very cheap $30 DX light that I got and modified. First the thermal properties are terrible, they actually mounted the copper heat sink to the anodized finish. This is completely unacceptable as it basically acts as a thermal barrier between the copper of the heat-sink and the body of the light. I do not understand over-driven lights that take things past the point of possible heat dissipation, because when researching all of the thermal properties of the led you will notice that the higher the temperature the less efficient the led becomes and the lower the efficiency the higher the temperature will be. This is going to cause 2 things first the high current will need higher Vf and that will most likely cause you to need a Boost driver or a higher V by placing more batteries in series, and using a buck driver to get to the lower, normal operating modes. This would cause some issues, the higher the supply voltage is greater than Vf for the led the lower the driver efficiency will be and that kind of defeats the purpose of the lower more efficient modes. There are a couple of options, you could design a light that has the sole purpose of being an over-driven single mode light. The other things you could do is to use 2 separate drivers and switch, or you could use PWM and a capacitor that would allow you to compensate for the poor PF that you would have. Most people don't care though, every time I see a new SST-90 light my engineering spirit weeps for our community. The constant reminder that it is capable of almost 3000lm if over-driven is obscene. These are driven at 9.0A and a total of 34W with a current density of 1A/mm2 and at 25C they can get 2750lm. How hard would that be for 34W of led power and 22C/W of resistance between the emitter and the case? Therefore you can say that unless your ambient temperature is 3C you will never be able to achieve these numbers, regardless of your build design. The spread sheet has some stuff that would say that you can if you were able to achieve some seriously amazing thermal efficiency, but I have my doubts, as well as the SR-90 not being anywhere near those numbers. I guess I am just bitter, but the only way I would over-drive an emitter is if I had somehow improved the thermal efficiency of the light to compensate for the extra waist heat that was being formed.

argleargle: I should be pretty good at therm o-dynamics as I got my training from the US Navy while training to be a nuclear operator, and I don't really like to participate in discussions that are just simple one line answers I like to think about the answers I give.