[Review] Lumintop / BLF FW3A - Managed to Get Tailcap Readings | Power & Thernal Regulation Graphs | -20% Coupon Code Added

The flashlight was sent to me by Lumintop for review.
Here's the product's link: BLF / Lumintop FW3A # Use code '3A20BI' for 20% Off


The FW3A comes in a regular cardboard box.



It's seated into foam for added protection during shipping.



The included accessories are the following:
2 x replacement o-rings, a pocket clip and a user manual.



The FW3A comes with a satin blue/grey anodization.



Some knurling is applied in the head and tail, while the body is completely smooth.



As opposed by its name, the flashlight comes with triple emitters.



The Carclo Frosted TIR optics provide a smooth, wide beam.



My variant arrived with 3 x XP-L HI 5000k emitter which produce a very pleasant natural tint.
A closer inspection of the PCB reveals that there's plenty of thermal paste installed.



The driver being used in an 1 + 7 + FET running Anduril.
It's kept in place via a brass retaining ring and it's using a short, thick spring.



The flashlight is operated by an e-switch placed in the tail.
The sample I was sent operates very smoothly and the clicky noise is quieter than a normal mechanical switch.



It's recommended to install the battery from the front portion of the battery tube as the tail can come apart pretty easily.
Here it is fully disassembled.



And a close up look at the switch itself.



The tail threads are triangular, while the head-side threads are square cut and way thicker.
Even though none of the threads are anodized, a slight rotation will disconnect the switch and practically lockout the flashlight.
(in reality the power is never disconnected, but not having the switch working in enough to prevent accidental turn ons).



From left to right:
Sofirn SP10b, Astrolux S43S, Lumintop / BLF FW3A, Fireflies PL47, Convoy S2+



User Interface

The flashlight is using the community's favorite firmware, Anduril.
Here's a diagram with all the supported actions.



Performance

I had to go through quite an effort to get an accurate tailcap reading due to the unique design of the flashlight.
In order to get my measurements I used a Vapcell 18650 2600mAh (Green) which can deliver up to 30A of current.

Here's my output measurements along with the respective current draw:


At the top of the ramp I measured 794 lumen, while on Turbo I got 2905 lumen and measured 12.4A of current!

Using the DPS5020 PSU managed to get the required measurements to create the Power Regulation chart.



What we can see from the graph:

  • The top of the ramp ( 8 x 7135) is fully regulated down to 3.5v. After that point the current drawn is directly affected by the battery's voltage.
  • The 1 x 7135 mode is fully regulated almost for the whole span of the battery, down to 2.9V.

And here's a thermal regulation graph with the Thermals set at 55C.



Things to point out:

  • Turbo output is sustained for the first 20 seconds, during which the flashlight gets pretty hot
  • After the 20s mark, there is a gradual stepdown down to ~210 lumen.
  • The 8 x 7135 mode (Top of the ramp) also thermal throttles and settles to ~350 lumen.
  • At all times (except maybe the first 20 seconds), the flashlight's temperature is kept pretty cool
  • At any point, Turbo can be manually invoked

How did you take the tail current measurements?

With the tailcap removed, you have to put a lot of pressure to the inner tube so that it makes contact with the driver board.
While maintaining pressure, and while having the battery’s (-) contact bridged to the outer tube via a wire, you have to momentarily bridge the inner and outer tube.
Each time you bridge the tubes, you essentially mimic a switch press.

To get the readings I had to have a second person pressing onto the inner tube while I did the rest.
Also, in the process I almost burned my hand while measuring Turbo :slight_smile:

Thanks for the effort and report!

Regarding thermal regulation, what happens if you begin at top of ramp ? Does it step down to 210 lumen also ?

You are welcome :slight_smile:

I will run the regulation test for the top of the ramp tomorrow and will report back!

I tested the thermal performance of 8 x 7135 mode (top of the ramp).
With 55C as the maximum temperature, the flashlight settled at 350lumen.
At any time the brightness can be manually increased.

Update: Lumintop sent me a coupon code for the FW3A:

Use code '3A20BI' for 20% Off. The link to Lumintop's store is in the first post.

Thanks for the review and for going through the trouble of doing measurements. Those are good data to read! :+1:

Thanks for doing this test. I like how it seems to come back up a bit.

What’s the story with optics … there was some kind of controversy but I didn’t read all the posts. If we order from Lumintop do we get some kinda inferior one to carclo ?

Yes, Lumintop decided to go with an alternate optic supplier that has a slightly cheaper cost for them. It’s OK, but the stance of it mandated a change to a plastic lens. That was the big controversy. So now the optional Carclo optic and AR glass is available to purchase as add-ons, at least at Neal’s Gadgets.

EDIT: Ilumn is now selling the FW3A (LINK) and they state that they come with Carclo optics and glass lens. $49.95 for aluminum version, plus the have a discount going for an even better price. However, just 2 emitter choices right now — XP-L HI 1A and SST-20.

Another interesting thing I just found out:
Lumintop lists the FW3A with a ‘Standard TIR optic’, while the FW3C is listed with ‘Standard Carclo TIR 10511’.
The situation is getting a bit of frustrating…

New to the forum! It’s great to see so much support and information for an awesome light. I’m greatful to be a part of this forum. Thank you for your thorough pictures and descriptions. Currently rocking the FW3C. It’s quirky and sometimes problematic but hey, fixing and modding is where the fun starts.

To settle a debate going on in r/Flashlight, I was wondering if you could comment on the performance on Turbo between this 25A battery and this 15A battery. Specifically, will one put out more lumens than the other (for the first 1,000mah, let’s say)?

Looking at the voltage charts for 15A draw, it looks to me like they’d perform the same.

The overall performance would be similar, but the VTC5A would be indeed able to provide a few more lumen.

While on Turbo, the flashlight runs in Direct Drive mode. In DD, the only thing that limits the current draw is the overall resistance. The body’s resistance can’t be altered, so the only variable in here is the IR of the cell. The lesser the IR, the more current draw!

Under constant load (while the flashlight uses the AMC7135 to regulate the output - up to 2.8A in FW3A’s case) the performance, output-wise, would be completely identical.

thanks for the explanation. so in DD how do we calculate expected lumens based on IR?
probably completely wrong, trying to guess:
V (presumably 4) = I (12.4 in your case) R (.012 for your battery+ flashlight)
4/12.4 - .012= .31058 for flashlight resistance so assuming
lumens (2905) = power drawn (12.388*4 = 49.552W)
but you lose .018 going to a 30mOhm resistance battery (vs 12mOhm) so you would have 12.37A/12.388A so 99.85% * 2905 = 2900 lumens?

I’m sure this is wrong (and I added some unnecessary steps), just giving it a guess

There isn’t really a specific formula for calculating lumens based on the battery’s internal resistance. Each type of battery has its own response curve, and they’re all a bit different from each other. Each type and bin of LED has its own response curve too, all a bit different. The turbo output is basically where those two curves meet — battery voltage under load and LED forward voltage under load.

Ish. There are also springs and driver components and wires and such to factor in, plus temperature, cell voltage, cell age, LED age, and how clean the optics and electrical contacts are… and so on.

In general, a higher-amp cell like VTC5A will make slightly more lumens than a more balanced cell like a 30Q, and either one makes more lumens than a high-capacity cell like a 35E. At least, when running at a direct-drive turbo level on the rising side of the LEDs’ output curve. It’s also possible for a high-amp cell to jump completely past the peak of that curve to the falling/overdriven side, and produce fewer lumens… especially in single-emitter lights. This dramatically shortens the LEDs’ life span.

The difference in turbo brightness is kind of a silly thing though, and only matters with a fully-charged cell, with healthy LEDs, for a few seconds before thermal regulation activates. So I usually recommend that people don’t use a really high-amp cell. Instead, a 35E/MJ1/GA cell is a good idea… because turbo is extremely overdriven either way, and every other level performs better with a high-capacity cell.