Sofirn SP40 Headlamp

Thank you!
And the Sofirn SP40 headlamp kit are available on Amazon US, get one with 30% off code NOW! Please PM, if you are interested.

More information, please check this amazon link: Sofirn SP40

By the way, thank you all for comment your thoughts and suggestions. :+1: :+1:
We appreciated it a lot.

I confirm that the button light always stays on. It's pretty bright, so some people may feel distracted/disturbed by it.

By the way, thank you all for comment your thoughts and suggestions. :+1: :+1:
We appreciated it a lot.[/quote

Please make it happen and I will buy a couple :slight_smile:

I’m sure it will be hot sale if u listen to customers. :slight_smile:

Yeah, looking forward for a dedicated,modern headlamp that one day will be most wanted…

Sorry for the delay… here ya go.

Seems like this is a winner over the Convoy. But, I have my Lumzoo and a Boruit D10, and I already don’t use them :innocent:

Wait, why is regulation on high mode quite poor?

I didn't catch that, but yes. It looks like a thermal throttle at first, but I can't figure out why the output continues dropping past 300 lumens. I'd expect the battery, at 3500mAh, to last longer on high. Maybe not, though.

Do we have to ask gchart for a temperature vs. voltage vs. output runtime graph now? })

Yes, and bypass the springs if possible.
The driver may see a lower voltage drop that way.
On high, it shouldn’t be a problem, but on turbo with active cooling(running), should help.

That’s a bit much (I didn’t measure voltage), but here’s what I’ve got. Realistically, Turbo and High are the same thing except for the first few minutes, you get an extra burst in Turbo.

I haven’t done a disassembly yet, but it sounds like that might be in order. I’m curious as to what kind of driver this is using (linear, buck, or current-limiting resistor). Based on those curves, I’m almost wondering if it’s just a current-limiting resistor. :question:

Yes, that seems like it.

Maybe that’s why they were able to get to a lower price point than almost all headlamps.
They saved 1-2$ by making a simple driver.

Thank you very much. Very useful information! I think the Sofirn SP40 really needs a 300Lm mode. The temperature of the flashlight housing at 300Lm is quite comfortable.

But they already have XP-L drivers in a wide array of products :frowning: . I guess BOM is more relevant, though I question whether this choice could save more than $1 per unit. It seems silly to make this trade-off, but it would help explain why the price is so low.

gchart’s SP40 charts make this light look less desirable, but not worthless. The overall runtime is okay if you don’t mind the constant fall-off.

Here’s one he made for the SP32A v2, which uses the XP-L2:

Do you have to use the head strap that goes over the top of the head? Is that removable?

Nope, it works great as right angle light (without strap). Check the pictures in the OP. Even comes with a sturdy clip.

It doesn’t look removable.
It looks like you would have to cut it off at the rear attachment.

What I meant was can it be used as a headlamp with just a strap around the head and not the strap over the head?

Thanks, Chooma, it looks like you are right.

Ohhhh :person_facepalming:

It’s not removable, exactly… but if you never wanted it, you could cut it off. Or get creative and attach some Velcro to it to make it removable.

I’m just wondering if it’s just too heavy to use without the top strap. Since it’s so cheap I ordered just to be able to test out a 18650 headlamp as my others are either 3 AAA or 1 AA.

This one may not have stretchy webbing like the others since it has the strap over the top. I looks more like “belt” material. It may have to have the over the top “belt” to stay up.