Single LED 21700

That’s one of the innate problems with picking A Light, that it’d likely be a compromise. I don’t believe there’s any such thing as “good balance between flood and throw”, because cranking it up to get good throw in the hotspot will make the foreground right in front of you annoyingly bright and wash out what you’re throwing at. Unless you’ve got a deep reflector like the HS-801, which pushes out the spill way out in front.

Close-in, you will want a flooder, else it’ll be like lighting up things with a laser-pointer. But throw will absolutely suck even at 2k lemons.

Farther-out, you’ll want a throwier light, but then close-in, laser-pointer again.

I have issues choosing between my MH20 and MH20GT for precisely this difference, yet they’re almost identical other than the beam profile.

So, I often carry more’n 1 light, ’20 in my pocket, others in my bag. Right tool for the job…

Might be worth looking at the JKK21700 (Kaidomain, AliExpress, Banggood, etc) or Astrolux EC01 (Banggood).

Oh, and welcome aboard!

Edit: I read too fast… just noticed that you want to construct your own light. That’s awesome, and kinda invalidates my recommendations. My apologies! Carry on…

heat is always the enemy

I went with the XHP50.2 3 volt. At 4.56 amps (12-7138 chips) I get 1790 lumen with no fear of cooking the LED. This driver https://www.aliexpress.com/item/33024201368.html?spm=2114.12010612.8148356.25.45933cf1edOAr3 was built for the host you picked. At 6 amps probable just over your target brightness at 2300 lumens with a J4 bin. Not exceeding Cree’s current recommended max. which happens to be 6 amps.

Oh yes! That’s why I’m thinking of a 21700 host. Got more meat and surface area to dissipate heat.

Thanks! I looked at that awhile ago, spec wise, almost exactly the same as my Sofirn SP31v2 but with a bigger battery, and a bigger head on it.

Well I’ll be…
I was just eyeballing that exact driver earlier, but for the SST40, not the XHP50.2-3V. There’s an idea.
Hell… I won’t be going turbo often enough to truly worry about it, certainly good for the occasional giggle :wink:

Ya make good points there. I’ll be looking more into flooder type reflectors and all that.

My second pocket-light is a Xeno E03 in WW. A little floodier, but some diffusion film on the front glass would make it a hella nice flooder. How diffusey the film would determine the ultimate beam profile.

Some DFs are plain, and you’d have to open up the light and sandwich it between glass and reflector, while others have adhesive and can be stuck on (and peeled off, even repeatedly), so you can swap different types of DF, or none at all.

The question will be if you want a specific CCT/CRI.

At 3V, any of the larger die emitters (SST-40, XHP 50.2 3V) are going to have limited CCT options, namely +5000K and poor CRI. The largest selection of emitters and drivers will be a 3V, smaller die (XP size, or 3535), paired with an appropriate driver.

At 6V your options are much better, but you’ll need to find a boost driver. H1-A is a cheap, readily available option, the two drawbacks are limited modes (simple 4-mode) and recently it looks like they’ve downgraded some of the components for it to be less efficient.

12V (XHP-35 HI) is really more of a pain than it’s worth IMO.

Pre-made SST-40 S21-A’s are available at the Convoy store, just plug in a battery and go

Not in my experience, the drivers can have up to 5 modes + moonlight (with a choice of 3 moonlight levels), max can be switched between constant current and direct drive, max constant current mode is adjustable and the modes will alter as percentage of the max current chosen, and you can choose between 4 drivers which deliver max current between 2-3A, 4-8A, 7-9A and 8-12A.
Sooo, what did you mean by a very limited range of current?

In response to your clean, white light requirement, i’ve not seen one in action myself but the Luxeon V is meant to have minimal tint shift across the beam, the XHP50.2 will be a bit multi-coloured as it transitions from hot-spot to spill. The SST-40’s not too bad though.

I guess I should have clarified a little better :slight_smile:
Meant from Low Power to Medium to High to Turbo Mode power levels. So long as I get a decent sized, wide hot spot, or none at all if a dedicated flooder, I’ll be happy with it.
My steadfast requirement is that this thing needs to be pocketable without it being overly huge.

Was very tempted with the Convoy SST40 prebuilt light, but the review on it said that it heats up so fast that as soon as ya flip on turbo, it starts stepping down.
So right now, thinking about the LED4Power 6A board with the remote FET and XHP50.2-3V.

Convoy L21a with XHP35 hi

Coolness :slight_smile: The output would put me on the lower end of my target, but this would be more ideal.
But the problem is the driver, aside from the GXB172, what would you suggest for this particular LED?

I don’t know what you mean, it’s stock 12V 2,3A which is the sweet spot for XHP35

See TA’s test here

Here’s a link to the light

Wellp, that’s normally what you get when the light’s small enough to be pocketable. Not much thermal mass to soak up heat before everything else gets hot, few if any cooling fins to help dissipate heat, etc.

Yeeeeeap. Nature of the Beast.
But the SST40 is known to not be the most thermally friendly if memory serves.

Oh.

And don’t be tooooo disappointed if your first 20 or 30 don’t give you “exactly”,
what you wanting .

There’s LOTSA blokes on here been looking and experimenting for yrs.
And still looking. Chuckle.

Enjoy the life mate. it’s very diverse. and often frustrating.

XHP 50B 3V is only available in cool white, which is a huge factor in deciding.

The 5000K SST-40 beamshots I have seen look very nice. Throwier to get a bit more range, less tint shift, neutral temp and just a slight loss in output vs XHP 50. Either emitter will get a light HOT at max output and step down quickly anyway.

Unless I’m completely misinterpreting what their product page says…

that’s only a max range of 4A or less depending on which mode it is set to. So you get moonlight, whatever small amperage range, and optionally a direct-drive mode if you install the external FET. Am I wrong in understanding it that way? That seems far more restrictive vs a PWM’ed FET+7135 driver or similar option with output ranging from moonlight to direct-drive and including everything in between.

I’ll be honest and say I’ve never actually used the LD-4x, but from the datasheet, how I read it is that’s the setting for MAX amps. The mode mode groups then give you the tiers and are a percentage of that MAX. For example, if you set it to 3A, you can have up to a 5 mode group, and it’ll be a percentage of that 3A.

Alternatively, the datasheet says you can uncap it all and just go direct drive for the uppermost level as well.

That’s how I read it

I don’t think that’s the case because for each max amperage setting they also list an associated “down to” minimum current. All the reviews I’ve seen of their drivers explain it as working that way as well.