Short Review of Sofirn SP33 v2 with XHP50.2

Do they hold the T-shaped driver/switch board in place?

Great review JasonWW! :-)

Lately, I took some beamshots outside at 3°C / 37°F and the SP33 didn't get substantially warmer than my hand, even after quite some runtime on turbo.

https://budgetlightforum.com/t/-/47363/165

The tint shift is hardly noticeable when outside. You might recognize some yellowish tint on the edge of the spot, somehow identical to the SP32A V2 that uses the XP-L2. FWIW, the SP32A V2.0 heats up significantly on turbo while the SP33, being far more hefty, remains comfortable as a summer breeze.

For comparison:

Sofirn SP32A V2.0 (XP-L2)

Sofirn SP33 (XHP50.2)

Any idea on US availability?

They could be holding nothing and just prevent the MCPCB from rotating (and shearing the ledwires) when closing the bezel.

I noted those screws in another thread and wondered if they were doing retention duty for driver components.

Since then, I’ve removed and inspected them.

They are quite short, not long enough to retain anything on the other side of the MCPCB shelf, so they must be there to keep the MCPCB from rotating… or as conversation starters.

This is also what I think. They are just for anti rotation.

You can see in Dale’s thread where they don’t do anything as far as the driver is concerned.

I ran High mode continously for about 20 minutes walking around. It’s a slightly chilly 60°F and windy night. Heat was not even a concern and it didn’t step down. It was just barely warm. Should be fine.

If left in a hot room with no airflow it would surely get warmer, but even then I doubt it would get so hot that it would need to step down.

By this, do you mean buying it on Amazon US? I have not heard anything about it. Sorry.

Yes JasonWW, that's what I meant. Thanks.

Thanks for the review Jason, looks like a decent all around light. Will it fit the longer protected keeppower 26650 5200 as that's the only 26650's I have at the moment.

I think the sp33 ver.2 is referring to the current retail version with the xhp50.2.

There was an earlier version of the sp33 using the xp-l led.

I don’t have any protected 26650 anymore to try, but 21700 fits. The springs have a lot of height to them and can compress a lot.

So even though the protected KP 5200 is a poor choice for this light in my opinion, I think it would fit.

Obviously, you can also use an 18650 as well.

Did someone ask about this? I thought it was well known.

Why would it be a poor choice since turbo only uses 5.8A and the protected KP can sustain 12A?

I asked about ver.2 as I didn't follow anything about the SP33 at all until today!

That is such an old cell with poor chemistry and high internal resistance. You get a lot of voltage sag with it and boost drivers need as much voltage as possible.

The protection circuitry also adds resistance and reduces voltage.

What I’m refering to is mainly in reference to turbo run times. If you are only concerned about steady output on the lower levels, then it’s an okay battery for that.

I must have missed your question.

Here is DB Custom’s thread on the first version that uses the xp-l.

The thread transitions to the newer version.

I need to get with the times as I thought it had modern chemistry. I've replaced most of my 18650's with 30Q's but haven't replaced any 26650's as of yet.

I think the KP 5200 mah came out in 2014. They have since been replaced by the 6000 mah version which is superior. The blue Liitokala came out, I think, in 2016 and is also superior. There have been a lot of better cells that have came out since the KP 5200 mah.

Do you think the chemistry is any safer with the 6000 mAh?

They could have used screws with a bit larger head to press down the MCPCB against the shelf and use thermal paste in between instead of using thermal glue. :person_facepalming:
They abandonned the driver retaining ring, it is now glued.

Someone at sofirn has a fetish with the glue.

The older chemistry has to do with performance, not safety.

I’ll try to explain why I think the protected KP 5200 mah is not a good choice for this light.

A boost driver tries to put out a set amount of voltage and amperage to the emitter on Turbo.

On the other side of the driver, it is pulling in roughly half the voltage and roughly double the amperage. I say “roughly” because driver efficiency and some other things come in to play.

As battery voltage drops, the driver has to pull more amperage out of it to compensate. This is Ohms law.

Now the driver has its limitation on how much amperage it can draw to keep from burning itself up. The driver engineers will decide on a safe limit. Once this amperage limit is reached, the light will either step down the the next lowest level or maybe do a half step down. This reduces the amperage being drawn by the driver, keeping it safe.

I don’t have the batteries to test it, but I’m sure that a fully charged protected KP 5200 mah will show a larger amp draw compared to an unprotected blue Liitokala 5000 mah, for instance, due to its voltage sagging a lot under load.

What this means is that you can test these two batteries by running the light on Turbo for 2 minutes, let it cool, run Turbo again for 2 minutes, repeat over and over.

The Liitokala may be able to run full Turbo for a combined 30 minutes (just an example as I haven’t ran this test). While the protected KP 5200 mah may only get 15 minutes.

So the KP 5200 is a perfectly safe battery to use, but you won’t get as much run time on turbo.

I would love to see Maukka or other more professional reviewers graph the output of this light with some different batteries to see how they compare. Other boost driven lights have shown to give more Turbo run time when used with unprotected high drain cells.

EDIT: For more on this boost driver design, see post #49 below.

Sofirns engineers have said straight up that they like to use glue because they believe it makes the lights more reliable.

I’ve make it clear to them (through Tracy) that no one on BLF likes glue. We hate it.

That was a great read, thanks Jason. It's probably the same scenario with the 18650's then as I tested my protected KP 18650 vs the 30Q and the 30Q was substantially better.

Here is a comparison at 10A. You can see the big voltage sag. This is the unprotected KP 5200. If you add the protection circuitry, the voltage sag will probably be even more.

Oh yeah, I edited that explanation post above to make it a bit clearer.