I installed a Boost HX (CULPM1) into an old SD Mini yesterday, running Anduril2 on a FET+1 driver. I extended the LED wires a little, using 22 AWG, and both springs are bypassed. The SD Mini is about the same size and design as the MH20GT. I tested it with a few different batteries, trying to find the sweet spot in amps.
So far it seems like 8.75 to 9.25 amps results in the most output. The highest I tested was with a fully charged VTC5D and measured 10 amps with output about the same as 8.4 amps. I haven't seen any signs of the LED turning blue, or any other damage.
Best calibrated lumens at start was: 1440 lumens (1630 Tom E lumens)
had an "original" Luxeon V in it that had an annoying blue ring around the hot spot
it's in great shape, even though I EDC'ed it for quite a few months, maybe year or 2
it's a really nice quality compact thrower - good factory focus, excellent quality reflector, good AR glass
it was already modded with a FET+1 driver (not sure if a regulated 9 amp driver exists in this size)
has the lit switch so perfect for Anduril 2
I must say without any focusing done, the hot spot looks well defined. I used the original 5050 centering piece I had in there, so the 4040 Boost HX twists into position but seems to be pretty well centered, based on how the hotspot looks. I couldn't use Simon's 4040 centering pieces I bought because they are for 7 and 9 mm holes, and the SD Mini was about 7.8 mm.
I see djozz came to about the same conclusion, at https://budgetlightforum.com/t/-/61873/9:
I bought these from Simon, BIN1:8RF-fcbB46-B5-6000, pre-mounted. This one was on a 20 mm MCPCB that had to be trimmed slightly to fit.
I found on some builds 6A hits just above 1300 at 30s, and others that need 7.5-8A. There’s a lot of variance with these.
Why doesn’t Simon’s 8A driver run at 8A? I understand resistance but on some L21A units it’s around 6.4A and others 7.2A, never higher with a topped off 40T, both running at 1300 lumens. Must be to doing with the led?
Came across a faulty driver that maxed at 3.97A, what would have failed?
Yes, I assume there are variances in the LED's, maybe though these are worse than most? I thought CREE's were binned pretty good.
I'm not familiar with Simon's 8A driver but the only right way to do these high amps (8-9A) with these LED's is buck/boost, and that's probably expensive. If his driver doesn't do boost, then the circuit resistance matters big time. You need to do everything right - spring bypasses, decent size LED wires, decent cell. I assume his driver probably has more internal resistance than a FET+1, so all those make a difference. Basically, you need higher amp capability in order for his driver to regulate or buck down.
The 40T is good but still you need to address the rest of it.
Btw, in the past when I used to buy drivers, we were always buying 4 amp, 5 amp, 6 amp rated drivers relatively cheap, and I could never get the rated amps out of them, ever... It's not surprising. 2-3 amps is easily do-able, above that, it's not easy.
Here's what Simon's HX looks like mounted in the SD Mini with the MCPCB trimmed, 22 AWG wires. The opening was more like 19 mm, and clearance had to made for the switch PCB wires
Hi Tom!
You take these longer awg26 wires to limit the amps?
So it would be a risk for the LED cause of the FET driver?
It should be an easy mod otherwise, or?
Yes - longer smaller gauge wires to reduce amps with the stock FET+1 driver. With the GT Mini I used a 35E and an older 30Q. 30Q did a little better, about 9 amps, while the 35E did about 8.6 amps. I've found max output is about 9 amps, but of course, output and amps will drop as the battery drains.
My GT Mini already has spring bypasses so I left them in. I specially like to leave the tail spring bypass in because my amp readings on the clamp meter with the tail cap off better reflect true running amps. If there was a poor tail spring, running amps will typically be lower then what I measure.
I've found the Boost HX performance to be quite good. Lumens at 30 secs is in the 1300's, at start lumens in the 1400's. Seems lower than what the tests indicated but still, good output for this type of LED, comparable to a XPL HI in a FET+1, but the XPL HI is at lower amps. The stock XPL HI did around 145 kcd.
Yeah - I went straight to the Boost HX. It matches well to FET based drivers, as Funtastic said. You still have to be careful though with measuring the amps and adding some resistance. Seems like the Boost HX's Vf is a little lower than the SST-40, though I believe 9 amps is about the max ideal for both.
Yeah understood about the FET drivers, I was thinking in terms of the reflector and suitability to the Osrams. Can’t find the post now but I think Zozz tested the CSLPM1 and only got a negligible increase in throw.
Edit: my D80v2 with SST40 just starts turning blue on turbo, don’t think it’s pulling that many amps though