November 23, 2017

BLF-A6

This was my favorite flashlight until I discovered the Convoy S2+. It still ain't bad and is a close runner up. This light can be called a 2 group 7/4 light. I like the first mode group (with 7 levels) and like the light to com up in level 1 (moonlight). 
Mode group 1:
1: 0.45 lm / 2.66 mA / 39 days
2: 10.1 lm / 11.87 mA / 8.7 days
3: 64.5 lm / 139 mA / 18 hours
4: 187 lm / 385 mA ? / 6.5 hours
5: 417 lm / 1.48 A ? / 100 minutes
6: 798 lm / 2.96 A ? / 50 minutes
7: 1386 lm / 5.65 A ? / 26 minutes
Mode group 2:
1: 9.72 lm / 11.87 mA / 8.7 days
2: 139 lm / ? / ?
3: 578 lm / ? / ?
4: 1386 lm / 5.65 A ? / 26 minutes

Like the Convoy, it is a phenomenal bargain at just under $20. As far as I know, you can only buy it from the Banggood site. When I ordered these lights in 2017, they shipped from a depot in the City of Industry in California and arrived in under a week. I would have no hesitation about ordering from Bangood.

This light uses a single 18650 cell. It meets my criteria for a light, which are as follows:

This is a fantastic an amazing bargain at $20 !! Compare it to the Zebralight SC600 for $100 or the Fenix PD35 at $70. Even if these lights were all the same price, I would choose the BLF A6. I immediately ordered two of these after a friend showed me his. They are only available from Banggood at the best price. You can sometimes find them on Amazon from some other seller at a higher price. In November of 2017 I see them on Amazon for from $30 to $50, so if you are nervous for some reason about ordering from Bangood, there you go.

This light was designed by folks on Budget Light Forums and has open firmware, which is a fascinating topic, but not one I am likely to make use of.

The pair I most recently purchased came in boxes with "Astrolux" on the label as well as the usual BLF-A6 (3D) markings. What I am reading is that the BLF-A6 is also being sold as the "Astrolux S1", which simply includes a short tube for 18350 cells.

My friend ordered one long ago and he said it took 3 weeks to arrive, being shipped out of China. I ordered my first pair on 3/21 from Banggood and they arrived 3/31, shipped from the City of Industy in California. My most recent order arrived in less that a week shipped out of California.

It uses the Cree XPL emitter and can deliver 1600 lumens. Single button at end, and will tail stand. It has springs at both ends of the battery compartment. You want the 3D version (neutral white), but 1A (cool white) and 5A (very yellow) are also available if you are crazy.

Some people are nuts about getting maximum lumens out of their lights. I have never used the "turbo" mode and could care less about it. For general use I find the third brightness setting to be ideal and plenty bright for walking around in the dark.

Interface

Hit the button on the back and it comes up in moonlight mode (wonderful!). Bump the button on back to kick it up a level at a time. This is all I ever use or need, but there are other features and tricks. It is possible to set a mode other than moonlight for it to come up in every time, but for me having it come up in moonlight is perfect.

Batteries

This light will accept virtually any 18650 cell. If you are unlike me and want to go crazy getting all the light you can out of the turbo mode, you have to pay attention to getting a high current battery and while you are at it, avoiding protected cells.

I use exclusively unprotected 18650 cells recovered from discarded electronic equipment. The word is that the BLF flashlight has its own protection logic and will shut down before damaging the battery. My experiments do not confirm this. However, the following claim is made:

Low-voltage protection will progressively step down the output at about 2.8V, and the light will shut itself off when even the lowest level gets below 2.8V.
Running from a bench supply, the light still operates at voltages as low as 2.4 volts. I would want operation to stop entirely at 3.0 or at the minimum 2.8 volts. At 2.4 volts the light is dim, but still operating.

So use care, swap and charge batteries frequently if you use unprotected cells. And by all means if the light seems dim, swap out the battery.

Modes and runtime

It is remarkably hard to find documentation on brightness and/or run times.

The Atrolux S1 (see link above) is simply a relabelled BLF-A6 and it has documented lumen numbers, which I transcribe into the table below. I got busy and measured current draw using a bench supply and obtained the numbers I give below. 

Mode 1  0.4 lumens  (moonlight)  3.4 mA  500 hours (20 days)
Mode 2  8 lumens  (low)		14.5 mA  133 hours (5 days)
Mode 3  51 lumens (medium 1)	134 mA   14 hours
Mode 4  149 lumens (medium 2)   430 mA   4.5 hours
Mode 5  344 lumens (high 1)     600 mA	 3.3 hours
Mode 6  672 lumens (high 2)     1.07 A   1.8 hours
Mode 7  1109 lumens (turbo)     2.48 A   48 minutes
Run times of course depend on what battery you use. The times above based on a 2000 mAh battery. (you can get 3400 mAh batteries, so this is quite conservative). Note that I have not measured these times, I have measured the current draw and calculated the times.

If you expect to use a different, perhaps better battery, just divide the mAh rating of your battery by the current for the mode in question, and you have your run time.

Alternate firmware

Apparently this is open source and all kinds of things are possible.
Feedback? Questions? Drop me a line!

Tom's Light Info / [email protected]