1

After my recent issues with an SST-40 FT03 I got curious about the current limitation in the Astrolux FT03. Over at the TLF we wonder if there are different driver versions for the SST-40 and XHP50.2 because of the different current requirements and limitations.

So far I thought at 100% the FT03 is in direct-drive and the current is just limited by the overall resistance of the current path (internal battery resistance, springs etc). I also wondered why it uses double BeCu springs until I realized that the same host is used for two different LEDs, of course.

Now the question is: If the overall design tries to minimize the resistance, how is it possible to not destroy the SST-40? People at TLF report no issues with high drain batteries and suggest that there might be a different driver in the SST-40 version that limits the current somehow. I’m not exactly sure who designed the driver, so maybe someone here can help me with my question.

2

Absolutely no limitation in SST40 version. They use same driver for both leds. And springs are not Be-Cu springs. Just steel.

3

+1 the SST40 can take a lot of abuse and the forward voltage is actually lower than a comparable XML2 and can handle much higher current, 8 amps before dying.

I am using my 3 volt xhp50.2 on the same Convoy fet driver I ran my sst40 on just fine and get 7 amps.

Bypass your springs.

4

There’s been reports of newer XML2’s that have died at just over 6 Amps

5

The newer SST40s have better bonding wires than the sample tested by djozz. Can’t remember exactly but I don’t think anyone’s on here exceeded 9.5 amps yet.

6

I measured 8,3 and 8,8A on my SST40 FT03s

7

I measured 8.85A on my dedomed sst-40 what output did you get at 30 secs? I got 2,520 at 30secs but that doesn’t seam right

8

I got 2100 and 2200 lumens at start. Don’t have 30 sec measurements and now both of them led swapped. 2520 seem way too much even a domed sst40. For a dedomed it should be even less. Around 2000 lumens at start. At 30s even less than 2000.

9

I am new to this so please forgive my ignorance on the topic. I am considering an Astrolux FT03 SST-40 and would like to get a couple of high quality 26650 batteries. I have read reviews on that flashlight that have mentioned Shockli 5500mAh, 20A continuous/30A pulse discharge; and the Orbtronic 5500mAh, 15A constant discharge; and other batteries were also mentioned. Are the two batteries listed, safe to use in the flashlight I am considering? Other questions: 1) Should the battery be protected or unprotected? 2) What is a recommended mAh range? 3) What is a recommended range for continuous current discharge? Thank you!