Short Review of Sofirn SP33 v2 with XHP50.2

Pretty sure my compressed driver spring was the culprit. Shipping with the battery installed could have caused this.

It certainly can be a problem. Lumintops ODF30 is also a boost driver light and it’s tail spring design used a metal tab. This tab was not very springy and if the light is bumped it gets a weak contact point and you loose Turbo. A lot of folks had this issue. Bending the tab back to get tighter contact fixed it.

The Rofis MR70, also a boost driver light, had issues with not going to Turbo. It was just an issue of weak battery springs or dirty contacts. Sometimes it was the Rofis battery which was protected. Later Rofis switched to an unprotected cell and Turbo lasted much longer.

I think once boost driver lights become more common people will start understanding them better. Just like with FET lights people learned to do spring bypasses to get more lumens.

BTW, spring bypasses help on boost driver lights as well. It gives you more total, cumulative, run time on Turbo. Anything that can keep the voltage higher at the driver will help on a Boost driver light.

Too soon to be certain yet about the spring as it worked well last night but the battery just came off the charger. Getting stuck in moon and failing to cycle through levels also comes and goes. But my battery was shaking around and now it is not. Fingers crossed.

The reason is chemistry. Aluminum oxide is an insulator.
Every aluminum surface exposed to the atmosphere has a thin layer of oxide on it, that wears off with friction.
The exposed aluminum surface then oxidizes within seconds.

That’s why flashlight threads accumulate black stuff that interrupts the electrical channel until threads are cleaned.

My SP33v2 seems to have high parasitic drain - measured 3mA (~3000microAmps)

I didn’t test the parasitic drain of my SP33v2 when I first got it, since I removed its battery after I tested it before.

But lately I left a 26650 inside for maybe just a month or so, and the battery has completely drained — and I haven’t really used that SP33v2 much.

Any idea if the SP33v2 just developed parasitic drain by itself, or it has that parasitic drain already in the first place?

For comparison, I tested only around 30microAmps parasitic drain for the SP33v3.

I don’t know. There might have been something wrong with the driver from day one. Maybe the MCU is not going to sleep for some reason?

I can see it developing a drain later, especially if it was dropped. Ceramic filtering caps do have issue of shorting internally when they are physically stressed. Sometimes they seem to go bad over time for no apparent reason. A shorted cap might be more than 3mA, though.

Thanks for the explanation.

No, my SP33v2 was never dropped. So it probably just went bad over time for no apparent reason… so fixing this parasitic drain requires ordering a new SP33v2 driver?

Yeah, I can’t see it having a drain anywhere else in the light.

$10 discount code for 2 HD 26650 5000mAh batteries: [5Z8E9KX85DXD](can be used 10 times only)

Sale price: $12.99 Discount price: $2.99

1.The battery fits in SP33 and SP33V3.0

2.Codes only work for our official website www.sofirnlight.com

Link:https://sofirnlight.com/products/plb-flat-top-hd-26650-5000mah-rechargeable-battery-cells?variant=31504670818364

Just noticed this ‘upgrade’ (+500 lumen) on their new Sofirn website

Interesting. I’m guessing they boosted the driver output.

I just ordered one of these from their site on February 21st. It’s currently being ready to be shipped out by China post (enough movement has happened for me to believe it’s actually shipped). I didn’t notice though if it was the updated version though… All the references I have to my order don’t say upgraded next to the name. If I got the older version, I guess I’ll have to make do with 2500 lumens. Strange how that was fine when I ordered it, but knowing if I waited two weeks I’d get a slightly more powerful one now makes that number a touch disappointing.

SP33 V2 uses XHP50.2(3V) now gives out max 3000 lumens. The driver was redesigned.

Are you mixing it up with the version 3?

Version 2 had boost driver.

Does it still have the 2 minute stepdown from turbo?

That was the only fault of this light, barring the 6000ºK.

Also see this mentioned in the specs: “Switch Mode: High/Middle/Low”. The sequence used to be L/M/H, not? And what does “Function: Hard Light” mean? “Light Source: LED Bulbs”??

Just wish most sellers/producers would write their spec sheets a bit more accurate.

Sorry, but this is some kind of horror. The SP33 V2 had an excellent brightness stabilization driver. In this “upgrade-degradation”, the brightness will now drop with the voltage drop across the battery. For what purpose? + 500lm? So the SP33 V2 and SP33 V3 now differ in the presence of built-in battery charging?


Immensely disappointed! SP33 V2 was one of your best flashlights. For SP33 V2, we only asked to remove the timer and add the ability to select the emitter CCT (4000K, 5000K).
Instead, the SP33 V2”new” received a primitive driver like on many other flashlights. If the matter is the rate of return, then it would be possible to increase the price and advertise a stable driver as a real advantage.
Bitter disappointment.

Thanks for reminding. We are short of workforce. We will update the information as soon as possible.

Thank you for the graph for the 2 minute step down across high output. I thought this was only on Turbo, now see why I had to re-click on those longer runs.

If Sofirn wants to capture a larger clientele, they’ll have to act more intelligently. This “upgrade” is not! Was my recommendation to field operatives. Not anymore.

Much that I applaud the inclusion of the batteries with most of their flashlights, their change of better emitters (SST20 vs. XPG2) and adding On Board Charging; the nomenclature of some lights is so confusing. What is the problem of using Vx.x where the first ‘x’ describes a major change and the decimal ‘x’ pertains to a slight change?
They have the SP10A (and then the SP10B) now superseded with the SP10S. The SC31 -> SC31B which follows an alpha upgrade, others using a numerical.

Any would be first time buyer is so confused that they drop their selection. I’ve had that happen to some co-workers. Then the product description is sometimes so poorly written that it just screams “good enough China product”.

Doesn’t inspire confidence nor trust…

Look again, High was 150 minutes, not 2.