FW3A, a TLF/BLF EDC flashlight - SST-20 available, coupon codes public

How many amps does it pull on 8x7135?

That is also an option :slight_smile:

I'm pretty sure 35E's and GA's will pull higher than 10 amps, but it doesn't stop me using them in single cell triple or quad FET driven lights. We also drive 3 amp rated LED's at 6+ amps, so.... What does the rating mean? What's the impact on the cell, long term? Or how much it lowers the rated capacity? Could be that a 35E would actually drop wayy down in capacity, lower than a 30 Q at 3000 mAh when driven at over 10A, but again, that's if you used it on max for all usage, even though in short bursts.

If most of your use is at lower levels, than the higher capacity 35E's and GA's, I think, are still worth using in these high drain lights. Guess it all depends if short burst use at >10 amps draw is causing true permanent damage, I'm thinking not so much, but dunno.

Usually the current regulators are about .350A each. So 8 x .35 = 2.8A

I think TK said the continous output for the light was closer to 2A, but if it can run at 2.8A (like in cold weather) then that is still well within spec and nowhere near the continous limit of almost all 18650 cells.

When is production?

This is not relevant and I’m not sure why you ask. It is common that the battery rated at 10A continous is also rated for higher amps for short periods. Like 15A for 20 minutes or 30A for 1 minute, something like that. Samsung and Panasonic/Sanyo did not list these higher discharge rates for the 35E and GA, but we can guess based on other, similar batteries.

Since the FW3A can only handle 10A or maybe 15A for about 30 seconds before thermal regulation kicks in, any battery should easily be able to handle that.

A big part of measuring continous discharges is temperature. Some batteries have a spec that they can’t exceed 70°C, while others might have an 80°C limit. Turbo on the FW3A is never going to last anywhere near long enough for any battery to get anywhere near these thermal limits. This is why I think continous battery discharge specs are irrelevant for the FW3A. It might be relevant on a much bigger light that can do 5000 lumen continous, but the FW3A is way way too small.

Ah gotcha, thanks. If I thought about it I would have realised I knew the answer to this from researching the Convoy S2+.

This might be a noob question but similar to stacking 7135 chips to the S2+ to increase output, would stacking more chips on the FW3A be a sensible option to increase regulated output? Provided there is space that is. If so I guess the firmware or ramping steps would need tweaking?

^ Probably Not. It already has more chips then it needs.

Lets say u will put the light underwater just for test, then the light will draw more since it will have lower temps underwater and draw more amps right… i will use lg hg2 have a spare extra for this light, might buy later 35e for more runtime or whatever.

I don’t think it would be sensible. If you stack them on the outer chips then the battery might not touch. If you get past that, the ramp rate would probably have a blip where it transitions to the FET. I also don’t see a need for it. I don’t think the light will run continuously using the existing 7135 chips at full power. Maybe if you are using the light in snow or underwater to keep the heat down then maybe you can run the chips at a higher level than stock. Maybe there is room for 1 more chip stacked on the one on the inside of the driver making it a 1+8+FET driver. IDK, it doesn’t seem sensible to me.

Keeping the exterior of the light at a constant temp should have no big effect on the max amps drawn. The thermal regulation is there to reduce amps so you don’t burn yourself. Secondly is maybe to keep the led and driver from burning up. So it depends on what you mean. In a 30 to 40 second blast on turbo the amps it draws is mostly from electrical things*, not from temperature. If you keep it cool then you can draw the same amps over a longer period of time which I guess you can call “more amps”.

I’m not real sure what your asking here. Sorry. :partying_face:

  • by “electrical things” I mean the battery, leds, driver, led wire, springs, etc… Of course the led gets hot and that reduces it’s output and the battery gets warm which might make it put out a tiny bit more amperage. The springs might get really hot and add resistance which reduces amperage, etc… so regardless of the lights exterior temp, there are a lot of temperature related things going on inside the light which can effect the amount of amps that get drawn.

Oh don’t worry I wouldn’t do it, was just thinking more from a theoretical point of view.

I’m not going to make a recommendation per se to exceed specified performance limits, but based on the following, I think the best of the current 3500mAh cells such as the NCR18650GA are reasonable choices for this light for people with a good understanding of their battery’s limits. If in doubt, of course, there are good higher current cells like the 30Q easily available.

I only found one copy of an alleged NCR18650GA datasheet, from Orbtronics, who sell this cell and protected batteries based on it:

It did not have an explicit maximum current spec, but they show continuous discharge data to 10A. At this rate, in 22 Celsius ambient, it reaches the maximum rated temperature of 60 Celsius right at the very end of the discharge.

HKJ and Mooch both provided favorable assessments at 10A continuous. Both tested it to 15A with no observed issues aside from exceeding the specified (conservative?) maximum temperature during sustained use. Mooch even did a continuous test at 20A and a pulse test (5s on, 30s off, repeatedly) up to 40A! Those are clearly excessive conditions, but the cell held up. The Samsung 35E and LG MJ1, had nearly as good of performance.

I know all of these cells have been tested in the Emisar D4, which is a higher power light than the FW3A.

Neither of these lights are capable of continuous 10+ Amps without taking deliberate measures like water or ice cooling. In normal conditions, the sustained performance due to thermal control would be something like 2-3A.

Jason, your sig line is getting pretty long … when you answer several people consecutively your signature line fills the page. You might want to consider condensing that somehow. I always figured a signature was just that, your signed name, not a free billboard. :wink:

I run VTC6 and HG2 in my FET 18650 lights. I run protected cells otherwise, almost all 18650GA and some 35E.

I was worried about mine getting long!

You can start a thread containing links to your builds then just have a link to that library in your sig line. In that way anyone wanting to see what you’ve done can get there easily while your posts stay streamlined. :wink:

jason has the biggest signature on blf :smiley:

Agree, they are even worse on mobile. If Jason & Teacher post in the same thread it’s a nightmare :smiley:

Great idea :wink: :+1:

Maybe, but in the big scheme of things, who really cares?? It contains good information and is neatly done & organized as well.
Live & let live…….

:smiley: …… Hmmmm, Interesting…. ‘Sig Lines’, the thing nightmares are made of. :smiley:

I’m on mobile most of the time too. :wink: