CD…… thank you for your response. I always do my best to find answers for myself before asking, but I did not understand what I found and that was the reason for my post.
Your example does not clarify things for me, maybe I am missing your point. No, I would not automatically assume that a car with a 18gal tank is “better” than one with a 12gal tank, but I would assume that the 18gal tank would take you farther than a 12gal tank and the tank size in your example should not affect the way either car performed. However, using your example, tank size= mAh, then my understanding is the bigger tank should give you more to draw from…… wouldnt that be accurate?
Using these 3 batteries as an example:
Samsung 30Q——3000mAh——15A
LG HE4—————2500mAh——20A
Panasonic NCR—–3400mAh——? A
So if I understand correctly the Samsung has a 3000mAh ‘tank’ and the current draw down is 15amps, but the HE4 has a smaller capacity tank(2500) that draws faster at 20A. What reason would someone have for purchasing the HE4(with a smaller tank that emptied at a faster rate) over the Samsung? Seems the Panasonic might be the obvious choice(if the rating means anything) but I was unable to find a listing for what the amp draw was for it. The difference in price between the batteries is negligible but because of my lack of experience with Li-ion batteries all I have to go on are these numbers, but they don’t make sense to me. What am I missing? I realize my logic is probably flawed, Im just trying to find out why.
I don’t like using an excuse for not being able to understand but it may help here. 15 years ago, I was in an car accident where I suffered a traumatic head injury and I was very lucky to survive. It has affected the way that my brain processes and understands info. I hope knowing this makes it easier for you to understand my frustration. It may have been easier if I had just run a poll and ask BLF users…… “what is your favorite battery” and forget about trying to understand the numbers. I do appreciate any attempt to help even if I am unable to understand.
Amp draw is the maximum speed (current draw) that you can pull out of it.
If you have a device that has a very high requirement for current then you need a battery that can supply it. The VERY high capacity batteries generally do not have the ability to sustain a very high current draw. There is some trade off between maximum capacity and maximum current support.
There are variables in the capacity vs. discharge rate that one should take into account. There are also reasons to look at protected vs. unprotected cells.
Battery discharge efficiency is controlled by the current draw of your load and the internal resistance of the cell, the current draw is controlled by the required voltage of the load and the effective resistance of the load. The latest generation FET drivers can draw 5-6 amps with a single LED, go to multiple LED’s and that current demand goes up. I am of the opinion that in most single cell lights, batteries from any of the major manufacturers (LG, Sanyo, Samsung, Panasonic…) are all quite adequate. But, if your light draws more than the protection circuit in the battery will allow through, it will trip. I generally am not concerned in a single emitter, single cell light what battery I use as long as it will allow enough current to drive the emitter and driver. I also generally will use unprotected cells in my FET lights, the protection circuit will add to the overall resistance of the path. In single cell lights there should not be a performance hit if you choose a good brand of high capacity unprotected 18650 cell. For daily users with regulated drivers, 7135 chips, then your draw goes down to around 3 amps. In this case it is perfectly fine to use very high capacity protected cells in the light. I think that it is maybe even preferred. These lights may get dropped, wet or only god knows what else and I like the protection circuit in these cases.
I guess that I should have just said, stick with good batteries and chargers that fit your need! Also the really high drain rate batteries tend not to have as much capacity as their lower drain rate, sometimes protected, counterparts.
In a ‘hot rod’ light with FET driver, to get the best performance you need a cell capable of high drain. Up until recently, the high drain cells also had the trade-off of low capacity, but this is changing with some of the newer offerings.
In a current-regulated light, where a high drain is not required, then the cell with the higher capacity is the better choice.
You’re asking the right questions anyway. Best cell is subject to usage and performance objectives. If you have a light that is current regulated to 3A then the best cell would be the one with the highest capacity or capacity/price ratio since just about any 18650 can provide that much current. It gets trickier with FET drivers. To maximize output you would chose the cell that supplies the most current(and typically has lower capacity) but to maximize run time you would chose a cell that won’t supply as much current but will last longer. You have to decide where your priorities lie and base your decision on that or buy multiple cells and load the one most apt for the purpose.
An easier way to understand capacity/voltage, is to use energy. Energy takes both capacity and voltage into account and is represented in Wh (watts hour).
Here’s an very simple example: Take a high capacity, low drain cell, say the Panasonic 3,400mAh NRC-B. Technically this cell contains ~12.5Wh in optimal conditions, which means low current draw and operating temperature. But when you increase the amp draw, the voltage will drop even though if the capacity remains about the same, you might still get 3,400mAh, but you no longer get 12Wh.
In the case of a high drain cell, the voltage doesn’t fluctuate that much, and you get the same energy from the cell at various current draw levels.
I have noticed in my SkyRC MC3000 when doing discharge tests, a cell charging at 2A and then discharging at 0.5A had less than 1% variation in capacity, but when it comes to energy it was about 10%.
Electricity was explained to me long ago like the ‘water tank’ think already mentioned. With batteries or cells, the MAh rating is how much water the tank holds. Voltage is how much pressure that water has. And drain capability is like how big the pipe is that you’re drawing the water from.
A less simple answer:
Within whatever is technically possible you can have any combination of these three elements. It’s those technological limitations which usually put the ‘performance focus’ on one of those elements above the others in a given cell. To get the ‘best’ cell, start with the light it’s going to be used in and work backwards. Maximum brightness requires the cell to have a high enough drain capability to fully power the light- that sets one lower limit. How long you want it to perform at that level sets another lower limit. You can have more capability available of course but not less.
Cell voltage needed is a function of what type of driver is being used and what it does with voltage level. If automatic step-down to a lower mode is voltage-dependent, then a cell with a higher initial voltage will run a little longer before it steps down since it has more to start with. Percentage-wise it’s usually not a lot of time gained but it is there and it can be measured.
Look at HKJ’s cell reviews focusing on the discharge curves at the different discharge amperage rates. Since you know how much amperage your light wants, that table will show you how long the cell being reviewed can maintain that level. Then for maximum brightness with longest runtime get the cell that supplies your minimum needed amperage for the longest amount of time. Check that cell against the other candidates. In the best-quality cells you’ll begin to see that while there is some difference it’s usually not a very big one so you can’t go too far wrong with any of the similar top-rated cells. If you find a nice deal on a slightly lesser cell that may be the one to buy instead- money does matter for most of us and by this point you’ll know which way you prefer to go.
It’s good that you’ve shown an interest in your batteries.
Acquisition of the right battery is just one of the issues that users face in managing their power resources. I hope that you’ve taken the time to familiarize yourself with safety and operational considerations. If not, you might want to read:
In addition to reading up on the safety of lion’s, the next thing to do is define what you mean by “best”. This is one reason that HKJ does not say “this is the best cell” at the end of any review. Even for a given light (as you wisely posted in your OP) like the A6, different cells will be ‘better’ depending on what you ask of the cell.
Some people want cheap. Some want the absolute max brightness and don’t care how long that lasts. Some want the max run time (in which mode?). Someone else may be looking for a cell that holds a charge “forever” when not used so they can put it on a shelf and have it ready in an emergency.
You have some good cells to start with, Samsung 30q’s are generally regarded as very good for the A6. Compare them in your use case with the Panasonic cells you have. Does one come up short in some category when you compare them? Post that information and the people here who really know cells will help you fine tune.
I bought a couple 30q’s, and have over a dozen laptop salvage cells. The salvage cells maybe don’t last as long, but I can’t tell a difference in the brightness. Truth be told, I’m probably still comparing the output to my 2xAA LED lights I used to carry, because every time I turn on my A6, X6, and X5 lights I start to giggle.
Just like tuning hot rod cars, unless and until you can prove A is better than B with real data, you are just faffing around.
Thank you ALL for your comments. I read over them several times and I have learned alot.
As I said, I am feeding batteries to the A6, S1, X5 & X6 and from what I understand all
of these lights possess similar demand & performance characteristics.
I read a ton before choosing the Samsung 30Q and Panasonic NCRB as my first batteries
and I feel they are both excellent batteries. Since I do not have a lot of actual ‘run time’
experience yet, I could not tell you which is best nor do I have the knowledge to make a
‘educated’ choice, instead I am forced to rely on only what others recommend.
Ive rephrased my question, hopefully so I can better understand exacty what I need~
What would be the advantage of choosing 2500mAh 35A over a 3000mAh 15A for my
specific lights. Which one would have the longest runtime(15A?) and which one would
be the brightest(35A?) If I had to chose a preference I would say that I would prefer a
battery with a longer runtime or at least compromised in that direction. I mean with
modes, Turbo is super bright and only needed for hunting possum and I had rather hunt
em longer than burn their whiskers.
Now, let me leave yall alone so I can get back to my faffing
Thanks for your replies….
No one can tell you which one will work better for you.
You may like the 30Q cells because the flashlights you use are ever so slightly brighter. (Mind you, at the lower modes, it doesn’t matter which cell you’re using - they will both be the same brightness.)
On the other hand, you might find yourself regularly having to stop and change the 30Q battery. Whereas with the Panny’s, you might get by without switching batteries. In that case, you would probably favor the NCR18650B’s.
Only you can evaluate whether the marginal amount of brightness is worthwhile. Only you can evaluate your usage patterns.
How small a difference in output are we talking about? My guess is that because of the nature of the small batch of special edition flashlights, there is more variance between individual flashlights than variation in light output from using the 30Q or NCR18650B batteries. It is so small that you wouldn’t notice the difference unless you did a side-by-side test. (Of course, having just one flashlight, the only way for you to simulate this would be to take photographs using the same ISO, aperature, and shutter speed settings.)
So, why the hoopla over using high-drain cells in these flashlights? Because it is the nature of flashaholics to seek the maximum performance out of their flashlights.
But I can tell you that neither one of them will improve the performance of your new X5. }
The amp rate of a battery is what a manufacture claims the battery is capable of discharging at. This doesn’t mean for every use it will discharge at that rate however, just that in theory it is capable of doing so.
On high demand applications more amps will be needed.
To put this into flashlight context, if you have Low, Medium and High output modes on your torch.
High might require 3amps to operate correctly.
But Low might only need 0.2amps
Both will operate at the same voltage.
In order to for the High mode to work properly you will need a battery capable of delivering a constant 3amp current.
Now this is where it gets complex.
When a battery is under load it’s voltage will drop. For the LED to actually work correctly it needs the correct voltage, so if the battery can’t deliver the voltage, performance will suffer.
This is a plot of two different battery discharge curves:
They are at a 3amp draw.
In order to maintain the output you want the line to be as high up the graph as possible, this represents voltage. The longer the voltage stays higher, the better performing the light will be.
How far to the right the lines go is just your total runtime. But once the voltage drops below a certain point, this means little unless you are only using moonlight or low output modes.
To show you what this means. Here is a high performing 2500mAh and a low performing 3400mAh batter.
3amp draw is fairly high and what many premium lights use as a High or even Turbo output and is good for around 900-1000 lumens in some lights.
Note the red line at any point in the graph always has a much higher voltage than the blue line. This means the a torch is likely to be brighter and maintain that High output longer using the red battery than it would using the blue battery. Total runtime isn’t as high, but the blue battery will likely have been dimmer and/or dropped out of High mode long before the red battery does.
To take it up a notch. Some very high performance flashlights have a Turbo mode, where it will essentially direct drive the LED. In such lights you can see over 5 amps of current draw. Some high capacity batteries just can’t deliver this kind of current and some protected batteries might trip the protection circuit.
Using the same two batteries as above, you can see there an even bigger difference in voltage between the two batteries. Again the red battery will give you more light and more time producing high output. The blue battery is at this level really struggling and performance and high output runtime are massively compromised.
HOWEVER…
At the other end of the scale. Say you tend to use Moonlight or low outputs the most.
Well at only 0.2 amp draw the blue battery suddenly shines and matches the red battery under load (because the load is so much less). And note how much longer the runtime is for the blue battery.
So for High output and Turbo use, you want a high performing cell, which typically have had lower total capacity. They will give you the best brightness for the most amount of time. But total runtime until flat will normally be less.
High capacity cells perform well under light loads, this is where they can make use of their large capacity.
Now the above isn’t always 100% true, as there are a number of ‘hybrid’ batteries, like the Samsung 30Q’s, which offer a nice mix of high performance and high capacity. So for most uses it’s a win, win situation.
But there are circumstances where you may need to look at other batteries still. If you have a custom light that is maybe a triple or quad LED all running direct drive, then in theory they could pull 15-20amps. Often exceeding the abilities of the high capacity hybrid batteries.
Running a battery at or over it’s rated amp draw can damage the battery and reduce it’s length of service.
And remember, not all flashlights are made equal. Some will have electronics that will see very little performance difference from different batteries, while others will see massive differences.
Hi Dash,
I spent a lot of time reading the links your provided and they helped a lot……thanks a lot.
Just one more question. I know you emphasized “No one can tell you which one will work better for you” and I apologize if I am beating a dead horse, but….
I am in on Robo’s battery GB. I really didnt need any new batts because I had plenty Sams/Pana but they needed help to meet their quota and I thought I would pitch in and experiment with something new. I saw there were quite a few users ordering the LG HE4 2500mAh 20A and I was wondering why there were so many users ordering this battery because the rating, to me, did not look that good. FYI, I see on other sites they now make a new LG HE4 2500mAh 35A at a comparable price that I might consider if I understood more.
That was my primary motivation for starting this thread but I never got a definitive answer about the HE4. Do you know anything about this battery or what the interest is all about? What might I expect from it if I try it in my A6, S1 & X6 compared to the Sams/Pana.
From what little that I’ve read about the so-called 35A version, it seems that someone somewhere (the highly respected and never defined “they”) gave a description of the HE4 as being pulse-rated for 35A. This description then morphed (by dropping the “pulse-rated”) into 35A.
I would be very suspicious of any vendor advertising a 35A continuous output version of the HE4.
The Amp ratings are confusing in that they aren’t in any way related to what you get from actual use in a flashlight. They only represent the safe current limit the cells should be used at for a particular period of time, sometimes pulsed and sometimes continuous. In general they will give you a clue as to whether they might be good as a high Amp cell but in any given light different cells might behave slightly differently and not always as expected based solely on ratings. I personally think it’s a good idea to have a few different types to use and satisfy my curiosity but just comparing a few isn’t sufficient to declare outright which is better. I look at value vs capacity, value vs Amp rating, and then buy as I please at the moment but only a few at a time. LG cells in general seem to be a good value but have neither the highest capacity nor the highest drain but are reliably consistent so I have a few of several types. I’ll certainly get more of other brands and types as time goes by so this isn’t a pitch for LG but rather my perspective on cell purchase in general. If it seems a good value on a type I’d like to try I get some. It just so happens that so far I’ve been too cheap to buy $10 cells of any brand.
What I find so confounding is that flashlights, too, seem to have their own personalities. The battery that worked well for one, doesn’t work so well in another. And vice versa.
I wouldn’t get too hung up on this. As alluded to earlier, most HIGH output flashlights only pull around 3amps. And complete hotrods only 5-6amps.
Even the completely custom semi-insane multi emitter ones still pull sub 20amps and in such a setup heat and runtime usually become far bigger issues to make it not relevant.
The only difference that really matters is how a battery performs through it’s discharge curve at a relevant amp draw.
e.g.
Here is a 35amp 2500 Efest and a 20A 3100 Efest.
At 3amp there is not really any point using the 2500 cell. The performance is only marginally better for a short period of time and with much reduced runtimes.
e.g. in something like a Convoy S2+ with the 7135x8 driver, there would be no gain at all in the 35A ability.
At 5amp there is more of difference. So in something like a BLF A6 the 2500 battery will give you better output and for longer, although the total gain is still fairly small. But if you are lumen chasing, then you’d want the 2500 over the 3100 in this instance.
