# Review of 4Sevens Maelstrom S12 including outdoor beamshot comparison



## HKJ (Mar 25, 2011)

[SIZE=+3]4Sevens Maelstrom S12[/SIZE]














4Sevens makes many different flashlights, at the time of introduction the S12 is the brightest flashlight he makes (But brighter models has been promised). The light uses a large led and a special battery to get the high brightness in a small size. The user interface is very simple, there is no on/off switch, the button on the tailcap is only momentary on, to turn it permanently on the tailcap must be tightened. Turning on twice with a short pause between will change brightness between high and low.









The light is delivered in a cardboard box with a window. The box has plastic insert to hold the light.






The content of the box is: Flashlight, lanyard with split ring, 2 spare o-rings, manual. I believe that 4Sevens has removed the lanyard from the box, because the light has no holes for a lanyard!
The package does not include batteries or charger, this has to be bought separately.









The light has a smooth reflector with the big SST90 led in the center. As can be seen in the beamshot comparison this does not make it a thrower.









The light has some knurling on the front part of the head, this is mostly for decoration. After the knurling there are some small heat sink fins, but this is not enough to keep the temperature down, the light will automatic reduce the brightness when it gets hot (See runtime curve).






Looking at the backside of the head there is a metal bump for connection to the battery and two chips on the circuit board (I expect that there are more chips on the other side). 






The body (That is glued together with the head) gives a good grip on the light.






The threads between the battery tube and tail are square threads and there is an o-ring. 






Looking into the tailcap cap it looks like any other tailcap, but there is no switch behind the circuit board, the spring is connected directly to the ring. The button on the back of the tailcap will move the circuit board, this is used for momentary on. Tighten the tailcap will make a stable connection between the ring and the battery tube, this is used to turn the light on.






The button on the tail is not a switch, but will move the circuit board in the tail a little bit, this is used for momentary on. This interface makes it very easy to use the light for fast flashes of brightness, but the user interface will change between high and low when doing this. This is not my idea of a tactical light.






The tailcap has a white dot that can be used to see how far the tailcap is turned, but the body does not have any marking that say when the light is in momentary mode, lockout mode or off.






The light is supplied with a holster.












It is possible to use the holster with either bezel up or down. Notice the dent in the side of the holster, this will hold the light when it has bezel down.



Looking at this light there are a lot of details I think could have been better: UI that changes level when flashing the light, very aggressive thermal regulation, "low brightness" due to regulation. What I really like about the light is the small size with high brightness. It is also a nice detail that the batteries are standard batteries, although not very common.




[SIZE=+3]Technical specification and measurements[/SIZE]






This light is designed for 26650 LiIon cells with protection, this is not a common cell size for flash lights and 4Seven has produced his own cells for the light. These cells are much cheaper than the usual custom batteries.

Measured size and weight:
Length: 139 mm
Diameter: 31 mm to 46 mm
Weight: 250 gram with battery.

The light uses a Luminus SST-90 led.






The measurements are done at 3.7 volt and for high I have measured both with a cold and a hot light. The estimated lumen are scaled from the specified lumen. The measured runtime is to 50% brightness, but is not really useful, because the light runs a long time below 50% (See runtime chart). Because the light is not fully stabilized the power will change with battery voltage, at 4 to 4.2 volt it is 18 watt on high.






I have done two voltage sweeps, one where the light had time to cool down between each measurement and one where it was running for 10 minutes at full brightness, before I started measuring. As can be seen the light does not really stabilize the brightness, except when the light is hot and it runs with reduced brightness. The light turns off at 3 volt, this gives an extra level of battery safety.






The runtime chart also shows the missing regulation and the temperature regulation. With no cooling the light will drop to about 50% brightness within a few minutes, with good cooling (I used a fan), the light will drop slowly, following the battery voltage.
Without cooling the light will have a much longer runtime, because it is running at a lower brightness.

The light uses current control and has no flashing modes.



[SIZE=+3]Battery and charger[/SIZE]

Because this light uses a uncommon battery size 4Sevens is also selling battery and charger for this light, but it is possible to find batteries and chargers from other manufacturers.













The battery has a diameter of 27.7 mm and a length of 70 mm. The extra length compare to the specified 65 mm (26*65*0) is due to added protection circuit and button top. The copper from the protection pcb can be seen as the minus pole on the battery.
The capacity is specified as 3900 mAh, but the real capacity is higher.











I have done a full review of the charger here:






[SIZE=+3]Comparison to other Flashlights[/SIZE]

4Sevens Maelstrom S12, Fenix TK35, Fenix TK40











Sunwayled M40C, Crelant 7G3 XML T6, Olight M31 Triton











For the full comparison to other lights with graphs and beam shots see here.

The included lights are:


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## SoCal5150 (Mar 25, 2011)

Great review HKJ! I love my S12 for the amount of light for its size, but I agree with you on the UI not being "tactical" I wouldn't mind if it had a single mode only option.


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## HKJ (Mar 25, 2011)

SoCal5150 said:


> Great review HKJ! I love my S12 for the amount of light for its size, but I agree with you on the UI not being "tactical" I wouldn't mind if it had a single mode only option.



I like multiple levels on a light, but in my view a tactical light must be not change brightness due to a random press on the switch.
It would probably be much better if you had to press 3 times fast to change brightness, but it would still not qualify for a tactical interface in my view.


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## MichaelW (Mar 25, 2011)

This should make good winter lights.
I wonder if the X10 will be substantively different?


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## PoliceScannerMan (Mar 25, 2011)

Excellent write up, thankyou!


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## HIDblue (Mar 25, 2011)

Great review HKJ! :thumbsup:

I'm impressed with the output given how small the light is. I don't think I mind that the thermal protection kicks the output down when the light gets too hot. And boy, that SST-90 looks huge in that relatively small reflector.


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## wesinator (Mar 26, 2011)

When you measured current in that chart was that after it was warmed up? I thought 4sevens said it was supposed to be 6 amps.


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## HKJ (Mar 26, 2011)

wesinator said:


> When you measured current in that chart was that after it was warmed up? I thought 4sevens said it was supposed to be 6 amps.


 
The curves marked cold was before the light warmed up, the curves marked warm was after.


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## ti-force (Mar 26, 2011)

Nice review. I have accurate OTF lumen measurements of the light right here. My graph shows the difference in output with no heat sinking, hand heat sinking and freezer pack cooling.


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## mesa232323 (Mar 27, 2011)

I just ordered my s12 last night they don't have the batteries at the moment. :candle: how long has it taken everybody else to get their lights?


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## tab665 (Mar 28, 2011)

mesa232323 said:


> I just ordered my s12 last night they don't have the batteries at the moment. :candle: how long has it taken everybody else to get their lights?


there are people who have been waiting over a month for thier batteries. just got a high priced paperweight.


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## HKJ (Mar 28, 2011)

tab665 said:


> there are people who have been waiting over a month for thier batteries. just got a high priced paperweight.


 
You can always use a 18650 IMR cell to check the light, even a normal 18650* cell can be used for short bursts. Just wrap something around the cell to centre it in the light.

* Check my 18650 comparison for cells that can deliver 5 ampere.


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## Hogokansatsukan (Mar 28, 2011)

Very nice review.
I wish it only had one mode, or the second mode was activated some other way than clicking the tail.
Makes a good SAR light, but not tactical otherwise. That is the lights biggest fault.


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## infinus (Mar 30, 2011)

I wish it could use 2 or 3 18650's instead of the 1 bigger battery. Then it might be able to run with full regulation for a shorter period of time.


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## dwminer (Apr 1, 2011)

Another great review, thank you.
Dave


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## vinhnguyen54 (Apr 3, 2011)

infinus said:


> I wish it could use 2 or 3 18650's instead of the 1 bigger battery. Then it might be able to run with full regulation for a shorter period of time.



I am not sure on this but I think the light thermal regulation is intervening not the lack of voltage for current regulation.


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## HKJ (Apr 3, 2011)

vinhnguyen54 said:


> I am not sure on this but I think the light thermal regulation is intervening not the lack of voltage for current regulation.


 
If you look at the runtime curves or the voltage scan you can see the regulation or lack of regulation, even when the light is cool.


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## lucio (Apr 10, 2011)

Maybe it's a stupid question, but I wonder:

Do you remember about the possible dangers arising from having two CR123 of low quality?

Well, how does this light stack up at safety, with such a powerful battery?


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## HKJ (Apr 10, 2011)

lucio said:


> Well, how does this light stack up at safety, with such a powerful battery?


 
Fairly well: 


 It only uses a single battery, this means that you have no risk of reverse polarity
 Both the light and the protection circuit will stop drawing current at a voltage well above any dangerous low voltage.
 The thermal regulation will reduce power long before the battery gets to hot.


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## lucio (Apr 10, 2011)

HKJ said:


> Fairly well:
> 
> 
> 
> ...


 
Thanks!


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## Volvo (Jul 24, 2011)

Tnx for a awesome review. :twothumbs




> (But brighter models has been promised).


 Any news about that?


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## HKJ (Jul 24, 2011)

Volvo said:


> Any news about that?



In his 2011 catalog is a S18, but I do not known when it is released.
There is also the Olights, 4Sevens (David) is closely connected with them now.


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## Volvo (Jul 25, 2011)

I´m looking forward to read about them light´s 

Have you any kind of performance on the S18?

I did som search and find a picture on it, but no performance?


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## HKJ (Jul 25, 2011)

Volvo said:


> Have you any kind of performance on the S18?
> 
> I did som search and find a picture on it, but no performance?


 
In the catalog (It is on 4Sevens frontpage) it says 1200 lumen, but that value may change before the light is released.


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## candle lamp (Jul 27, 2011)

Thanks a lot for your excellent review as always. HKJ ! :thumbsup:



HKJ said:


> If you look at the runtime curves or the voltage scan you can see the regulation or lack of regulation, even when the light is cool.


 
I can see the *irregular curve *on the runtime chart within about 3~12 minutes.
(Also I can see the same in the review of Maelstrom X10.)

And you say that the runtime chart also shows the missing regulation and the 
temperature regulation. 

What would be the reason for this irregular curve or missing regulation even in case of cooling?


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## HKJ (Jul 27, 2011)

candle lamp said:


> I can see the *irregular curve *on the runtime chart within about 3~12 minutes.
> (Also I can see the same in the review of Maelstrom X10.)
> 
> And you say that the runtime chart also shows the missing regulation and the
> ...



The light does probably not have any circuit to boost the voltage, i.e. the current battery voltage will limit the maximum brightness. This makes the maximum brightness the same as for a direct drive light, but with the possibility to reduce output when the light gets hot.


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## candle lamp (Jul 27, 2011)

HKJ said:


> The light does probably not have any circuit to boost the voltage, i.e. the current battery voltage will limit the maximum brightness. This makes the maximum brightness the same as for a direct drive light, but with the possibility to reduce output when the light gets hot.


 
Thanks for your reply.

I can assume the light has buck circuitry. As far as I know, many 4 seven lights have [FONT=&#48148]buck and boost circuitry with a working voltage.[/FONT]
[FONT=&#48148]I don't know the reason why the light has buck circuitry only even though it is powered by high capacity battery 26650. :shrug:[/FONT]
Maybe it's because of reducing output due to heat.


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## sunthrow (Jul 27, 2011)

It is normal for my S12 to pull only 3.1 amps on a fresh 26650 battery.
Some people said 4 or 4.5 amp, i dont know if this will affect the ouput of the light or all s12 light as aprox the same lumens range each other whatever the power go to the circuit.


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## HKJ (Jul 27, 2011)

sunthrow said:


> It is normal for my S12 to pull only 3.1 amps on a fresh 26650 battery.
> Some people said 4 or 4.5 amp, i dont know if this will affect the ouput of the light or all s12 light as aprox the same lumens range each other whatever the power go to the circuit.


 
If the S12 is cool, it can pull around 4.5 ampere, but that is without a ammeter in series with the battery. The ammeter can easily drop enough voltage that the current is reduced to 3.1 amperes.


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## infinus (Jul 27, 2011)

Not only what you just said HKJ, but sunthrow also used a fresh battery, which would have a higher voltage than what you made your charts above at. Probably a combination of the two in play.


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## HKJ (Jul 27, 2011)

infinus said:


> Not only what you just said HKJ, but sunthrow also used a fresh battery, which would have a higher voltage than what you made your charts above at. Probably a combination of the two in play.


 
A fresh battery might be 4.2 volt unloaded, but drops down to between 4 and 4.1 volt with a load. My "voltage sweep" is done with a bench power supply, where I can keep the voltage at 4.2 volt with the light on.


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## thedoc007 (Jul 17, 2014)

Will this light work with an unprotected 26650? It seems doubtful, since in your cell the protection adds a full five millimeters. But I want to make sure.


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## HKJ (Jul 17, 2014)

thedoc007 said:


> Will this light work with an unprotected 26650? It seems doubtful, since in your cell the protection adds a full five millimeters. But I want to make sure.



This model is a couple of years old, the current model may be different!
Do you need info for this model or the current model?


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## thedoc007 (Jul 17, 2014)

HKJ said:


> This model is a couple of years old, the current model may be different!
> Do you need info for this model or the current model?



This model. I have a MMU-X, and I can confirm it works fine with unprotected. But I have an extra unprotected 26650, and want to give it away. He has the S12, and needs to know if it will work with the shorter cell.


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## HKJ (Jul 19, 2014)

thedoc007 said:


> This model. I have a MMU-X, and I can confirm it works fine with unprotected. But I have an extra unprotected 26650, and want to give it away. He has the S12, and needs to know if it will work with the shorter cell.



I have been looking around, but have not succeeded in locating the light.


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## thedoc007 (Jul 19, 2014)

HKJ said:


> I have been looking around, but have not succeeded in locating the light.



Thanks for looking. I'll know in a couple days whether it not it works, and I'll be sure to post it here.


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## thedoc007 (Jul 23, 2014)

I can confirm 100% that the standard 65mm cell works fine. A Kinoko high drain 26650 sans protection circuit is just fine, despite being a full five millimeters shorter than the FourSevens branded cell.


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