Probably a DUH question, but do I need a 'special' 18540 with an SST40?

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Mr.Shnatter
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Probably a DUH question, but do I need a 'special' 18540 with an SST40?

I just got a Gray Convoy S2+ SST40 1800lm 6500K Temperature Protection Management 18650 Flashlight

getting ready to see so much brighter than the XM-L2 convoys I have, I realized…. I get my 18650s from trade show give aways of battery sticks for cell phones.

They have 2200 mAH batteries in there. But there’s higher capacity 18650s out there.

The SST40 at full power draws 5amps? Or something more than the XM-L2 does, right?

Is a 2200mAH battery keeping the SST40 from putting out all the light it can?

What kind of battery should I use with the SST40?

I did notice the SST40 was brighter (with one of these 2200 mAH batteries) than the L2, but not by much.

Is the eye’s response to light linear? ie double the lumens will seem double the brightness to the eye?

THANKS!

oweban
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SST40 can utilise more than that – the “sweet spot” is 7.2A, after that is wasted. But that particular one will only pull 5A because of the driver.

It really depends on the battery that you’ve got though – 2200mAh is the capacity, so 2.2A for 1 hour, but the driver can pull 5A – but the battery may not be able to give it that much, really depends on what cell it is. Most 18650 pulls from things like phone charger batteries are usually fairly low powered, so might not be able to give 5A – do you have a model number off one of them?

As for linearity – nope. Four times the lumens is usually “double” the brightness, it’s a weird one. But then you throw in things like intensity vs lumens, etc etc…

A good cell for that would be a protected MJ1 from Illumn: https://www.illumn.com/18650-lg-mj1-inr18650-mj1-high-discharge-protecte...

The “protected” will make sure the battery won’t give any more power to the light when it’s drained enough to need recharging, so you can’t kill the cell by over-discharge – it also helps in that it won’t let the light pull any more than its rated output (in this case, 8A, at which point the protection circuit kicks in, like tripping a breaker).

Mr.Shnatter
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@oweban THANKS!

I’ve read that line a fair amount of time over past year / 2… maybe on this forum? about the mAh number being how much you can get out of a battery in 1 hour…. I’ve been mildly techie for my whole life. I always thought that rating was more of a midline calculation of capacity – you can get x mA over y hours multiplied together. (not trying to pull the max for 1 hour, but more that you can pull, maybe 300mA for 300/2200 = 7,3 hours for a 2200mAh battery

And figured that at either end of the spectrum, things fall apart – ie, you can’t draw 1ma for 2200 hours because the battery naturally loses charge over time and it will be losing charge as you draw that tiny current? And you can’t pull 8800 mA for 15 minutes because of limits of the chemical reaction, heat, etc.

Would you know? Is that a) ‘conventional wisdom’ or b) battery makers actually intend the mAH number of a battery to mean max over 1 hour?

A quick google had some sites mentioning x mAH for 1 hour. Others – this one spells out my thinking I think:

https://www.powerbankexpert.com/what-does-mah-stand-for-in-batteries/

And along the same lines, the rechargable batteries in UPSs, emergency lighting, etc. that capacity can’t really mean amount in 1 hour? I would think different chemical processes just aren’t made for high current as well as others?

If you have a room full of lead acid? batteries storing your solar cell power – that has lots of capacity. I doubt you can draw that max capacity down in 1 hour?

Sorry, a) don’t mean to shoot the messenger b) I’m going on too long : )

I looked through the 18650s I have. most say 2200mAh. 1 I just pulled says 1500mAh. a couple don’t have any markings ; )

Some sets of numbers from 3 of them (I left off things like 18650 and 3.7v (although 1 I saw said 3.6/4.2v (I think that’s the nominal voltage and charging voltage?):

MH61647

SZNS HO2N161EJ 514345

FST 7042315 09950 CJ

So 1800 lumens won’t look much brighter than 1000 lumens? : (

And yeah, all the calculations / terms has my head spinning. And the tightness of the cone (sorry, don’t know all the terms) has a huge impact on how bright it looks – I have some kind of a 18650 with a sliding focus sleeve. Make it a tight circle of light and it is much brighter than when it’s as wide as possible. But the LED hasn’t changed / amount of light being put out by it hasn’t changed.

Admittedly, not that it’s a huge difference in price, but me being me…. I have to ask – what do you think of, in the interests of cheapness, getting L2 flashlights rather than SST40s? This SST40 I just got was $15 deliverd. I have too many now, but the last XM-L2 I bought was $12. I’m likely not going to pop for the higher output 18650s so the SST40’s max output is going to waste?

I’d say though – if the SST40 is not running at max output with these cheapo batteries, it will live longer than the XM-L2 running closer to its max? And then the argument…. I’ll likely lose it before the LED reaches its end of life : ) ???

Oh, check this out. Googling the battery you mention, I come up with this:

https://rechargeablepowerenergy.com/products/lg-mj1-3500mah-cell-1

Cheaper, but is that the same thing? An MJ1? It talks of up to 10A, but then says ‘The low continuous rating on this battery makes it NOT APPROPRIATE FOR USE IN HIGH DRAIN APPLICATIONS (e-cigs, vaporizers, or similar), but this is an exceptional 3500mAh cell that offers a solid 10A max continuous with 3500mah, and up to 15A manufacturer pulse rating. ‘

At least for what little I know, the 10A, 15A it mentions doesn’t fit the ‘The MJ1 is a superior cell for the low-medium amp (10Amp), extremely high capacity battery packs, and applications. ‘ description.

Do you / anyone here you know have a homebrew current tester? Pop a battery in, the circuit is just a low resistance resistor (in oil / heat sinked) to see what current you can get? What kind of resistor? from my ham radio studies eons ago, to get 5Amps with 3.7v, you need a 1.35 ohm resistor? 18.5 watts though. I might have 1/4w ones from radio shack from EONs ago!

kwcha333
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thank you for your sharing

ggf31416
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Rated mAh capacity is usually measured at some low current with a rather low cut-off voltage, with useful discharge currents like 1C and reasonable cut-off voltages you get a somewhat lower capacity that isn’t as good for marketing, maybe 10% less. The Continuous Discharge Rating (CDR) is either stated directly on Ampers (A) or in C (multiples of rated capacity). If a cell has 2C CDR and 2200mAh capacity it means the CDR is 4.4A.

For the SST40 Convoy you want a cell with more than 5A CDR, the LG MJ1 or one the other 3500mAh cells will work for sure. The warning is because E-cigs need about 20A, there are high drain cells like the Molicel 2600mAh or the Samsung 25S that are better for that, also if you run a low drain cell on a high drain flashlight, while not recommended, the LED Vf curve will self-regulate the current at some extent, unlike pure resistive components like e-cig´s coils where exceeding the discharge rating becomes dangerous rather quickly.

zoulas
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Every light will be limited to the battery you use. I suspect the free batteries you are getting are crappy. Get a good battery from a reliable source.

oweban
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I’ll cover some points Smile

Quote:

I’ve read that line a fair amount of time over past year / 2… maybe on this forum? about the mAh number being how much you can get out of a battery in 1 hour…. I’ve been mildly techie for my whole life. I always thought that rating was more of a midline calculation of capacity – you can get x mA over y hours multiplied together. (not trying to pull the max for 1 hour, but more that you can pull, maybe 300mA for 300/2200 = 7,3 hours for a 2200mAh battery
And figured that at either end of the spectrum, things fall apart – ie, you can’t draw 1ma for 2200 hours because the battery naturally loses charge over time and it will be losing charge as you draw that tiny current? And you can’t pull 8800 mA for 15 minutes because of limits of the chemical reaction, heat, etc.

Yep, that’s roughly it. There’s always going to be something outside of it due to other factors (eg. a 3000mAh battery pulling 9A would last, on paper, for 20 minutes – but there’ll be other losses during that time and a bunch of heat, so it’d ramp down. It’s purely to do an apples to apples comparison.

It’s more like saying, my bottle of water is 1L or 4L – it’s just how much “juice” it holds. The wider the opening at the top, the faster it can come out, etc.

Quote:

MH61647

SZNS HO2N161EJ 514345

FST 7042315 09950 CJ


Yep, all cheap cells. For things like that, I’d be surprised if the batteries were 1.5C (C is the multiplier of mAh – so say, a 3000mAh battery that can do 1C can put out 3A, 5C can do 15A, etc). The 4.2V etc is more explaining it’s Li-Ion. 4.2V is fully charged, and you don’t really want to take one too far below 2.8V or so.
Quote:

So 1800 lumens won’t look much brighter than 1000 lumens? : (

Really depends on the emitter and reflector. SST40 at 5A can look quite bright; it’s a decently “throwy” emitter, vs the XML2 which is more floody. The S2+ is a fairly small reflector though, so it brings the SST40 back to being a bit more floody.
Quote:

Admittedly, not that it’s a huge difference in price, but me being me…. I have to ask – what do you think of, in the interests of cheapness, getting L2 flashlights rather than SST40s? This SST40 I just got was $15 deliverd. I have too many now, but the last XM-L2 I bought was $12. I’m likely not going to pop for the higher output 18650s so the SST40’s max output is going to waste?

I’d say though – if the SST40 is not running at max output with these cheapo batteries, it will live longer than the XM-L2 running closer to its max? And then the argument…. I’ll likely lose it before the LED reaches its end of life : ) ???


I’d spring for one good battery, just so you’ve got it in case you decide to get something else down the line with a bit more oomph, say a C8+ with SST40 and the 6A driver. That’s a far throwier host, so for longer distances. In term of “live longer”, do you mean as in wearing the emitter out? Won’t happen Smile XML2 can take a fair bit of current, and as I previously mentioned, people are running the SST40 up to 7A or so with no dramas, and it’ll still probably outlive them.
Quote:

https://rechargeablepowerenergy.com/products/lg-mj1-3500mah-cell-1

Cheaper, but is that the same thing? An MJ1? It talks of up to 10A, but then says ‘The low continuous rating on this battery makes it NOT APPROPRIATE FOR USE IN HIGH DRAIN APPLICATIONS (e-cigs, vaporizers, or similar), but this is an exceptional 3500mAh cell that offers a solid 10A max continuous with 3500mah, and up to 15A manufacturer pulse rating. ‘


That one’s the unprotected one, and can put out 10A – the protected one I linked can put out 8A, and won’t let itself drain too far to be revived (see my point re: going below 2.8V), so it’s a good option for if you’re not staying on top of things. That S2+ driver doesn’t have a battery check mode, so you’d need to kind of guess the voltage, or pull it every now and then and check with a charger or multimeter. With the protected cell, when it doesn’t work, it means recharge it Smile
Quote:

Do you / anyone here you know have a homebrew current tester? Pop a battery in, the circuit is just a low resistance resistor (in oil / heat sinked) to see what current you can get? What kind of resistor? from my ham radio studies eons ago, to get 5Amps with 3.7v, you need a 1.35 ohm resistor? 18.5 watts though. I might have 1/4w ones from radio shack from EONs ago!

There’s something like this: https://www.aliexpress.com/item/32813003104.html (but can’t vouch for it as I haven’t used it).
Mr.Shnatter
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Wow! Thanks! I’m changing my thinking. Might as well get the most out of the flashlights… maybe these junk batteries aren’t pushing the XM-L2s even.

1) So where to get a couple good batteries? You sent me a link. Thanks! Is that the best pricing? What about a vape store? I can see what they have and google the specs – aiming for 3500mAh or more, name brand, and a good C number would be ___ And / or CDR over 5 amps? Oh, and I want to make sure it’s protected?

Quote:
That S2+ driver doesn’t have a battery check mode

At least 1 of the S2 / S2+ I have – the light will start flashing or drop down in brightness… that’s my indication the battery is dying. But some have old / some have new firmware so they may not all have that.

2) this is the charger I’ve been using. I charge at .5amp (it could also do 1amp) any recommendation on this is ok? .5 or 1a charging?

https://www.dropbox.com/s/lb7t89fi2nvlkpb/2020-07-29%2009.24.11.jpg?dl=0

THANKS!

Barkuti
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Mr.Shnatter wrote:

1) So where to get a couple good batteries? You sent me a link. Thanks! Is that the best pricing? What about a vape store? I can see what they have and google the specs - aiming for 3500mAh or more, name brand, and a good C number would be ___ And / or CDR over 5 amps? Oh, and I want to make sure it's protected?

Whoa! That's a lot of questions.

Best pricing for something depends on many factors, the first of 'em is where you live and how much does shipping and handling burdens you, besides what and how many pieces do you want. The Samsung 35E ($3.99, long cyclelife) and the Sanyo NCR18650GA ($4.25, best overall high capacity cell performance) are also for sale there.

Vape stores won't sell you cells at the best price, as they're making business out of people's vices. This means you are paying cells burdened by nicotine. As a first choice I don't buy batteries in vape stores because of this. I've had enough dealing with addictions in my life and now I @#$% am not willing to allow any more money to go where it @#$% is not right. The amount of money squandered by mankind in addictions is just sick, ridiculous.

3500mAh or more? Sorry? The technology for “real deal” 3500mAh in 18650 format is still not (fully) here, at least as far as the reviews I've witnessed. The one which shows the highest figures is this “3500mAh” cell shootout @ Thunderheart Reviews, but if you look at Henrik's site his figures are slightly smaller (his reviews are also overall older).

I am yet to have a protected cell at home, I even went to the point of removing the protection from a few cells I had protected. Cells do not need protection unless you can't avoid them being discharged below 2.5 or 2V (absolute minimum). In practice, unless you leave your batteries carelessly connected to some non-stop draining device that can't happen. But if you can't be sure about this, then buy protected cells. A protected cell will be suddenly cut-off when its protection circuitry decides that its hitting a too low voltage, leaving you in the dark until the cell receives some charge (some voltage). This means you could be suddenly left in the dark, but of course it is pretty easy to notice such a thing (imho).

The Light Innocent I am

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Mr.Shnatter
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Seems shipping for any of these batteries is over $20 for just a couple batteries to the US? Am I doing something wrong? Or because they are lithium batteries, there’s higher costs / can’t be shipped on planes?

And that’s why I was thinking a vape shop might come out cheaper overall than the low prices people mention here PLUS the shipping costs.

ggf31416
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Shipping to Florida for example for a pair of 18650 is $5.25 in Ilumn, the price for other “mainland” states shouldn’t be too different. Other US sites should have similar shipping costs.

Mr.Shnatter
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Yes, I was looking at china sites. Any thoughts about 18650batteries.com ? They are a little cheaper for a couple Sanyo NCR18650GA batteries than illumn.

Any discount codes?

Barkuti
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You USA residents have many sites selling li-ion batteries for affordable money, just make a G00gl€ or some other search for “18650 batteries US” and you should get all sort of related results. In your particular case, looking at China sites isn't necessarily cheaper. 

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