Short Review of Sofirn SP33 v2 with XHP50.2

This is exactly what I reported at the beginning of this thread. I loose Turbo at 3.70 volts.

If you are loosing turbo at a higher voltage, make sure your battery connections are clean. Dirt or grease on the springs or battery tube ends might be causing a small voltage drop making the driver think the battery is at 3.7 or less.

As I said at the beginning of this thread, you will loose Turbo and High at 3.40 volts.

At 3.70 volts you loose turbo. Then the light will only cycle between low and medium. A double click takes you to High.

Same here. When my 26650 battery hits 3.9Volts, I lose Turbo and High.
Of course, I’ve had a FAULTY driver from the getgo.

I’d like another SP33 when they hit Amazon USA. Had it not been for Sofirn’s help, I don’t think the refund would have been handled as quickly as it was. That’s why I would wait on Amazon. Don’t care to be jousted around by Ali.

Yeh, I’m looking for a good sample of this torch. I like it. Size is perfect in hand. :+1:

So is it working properly if you lose turbo at 3.7?

I’m guessing post #1 was not very clear on this topic. I rewrote it to better explain. Here is the new section from post #1.

Thanks, I understand your 1 st post . It just seems too early to be losing turbo but I don’t know. That is my question. I’m not to sure of the math . I suppose with a regulated output, the lumens can’t just drop off . That would make sense . At 3.7, it can no longer make 2200 lumens.

This is why after 2 1/2 years of Elect. Tech. I chose another career path. :smiley:

Thanks Jason. Yeah, I tried that and nothing. I contacted seller awhile back and they said they would ship a replacement. I’ve asked them twice if they’ve shipped the replacement but nothing but silence. I just opened a dispute with AliExpress.

It’s been 2 months.

I do understand that.

If it was just for myself to play with there’s no concern. I just don’t want to buy in bulk and have to thoroughly test each one before selling it. When getting my own branding it’s 50pcs per model. The lack of reviews on the SP33 and the few people that received them, some have issues so I’ll hold off until the bugs are sorted. It’s $8.70 USD per KG shipping to New Zealand. Shipping costs a lot more as I purchase bulk cells too using an express service.

I’d also be bundling the Sofirn 26650 and it’s unclear how long it’ll last on Turbo since no one has tested? I don’t really want to import other 26650’s just for longer Turbo as it’ll up my prices and I don’t really want to go that route

Remember that a resting voltage of 3.70 is pretty much a dead battery. I usually recharge them or swap them out once they get under 3.8v.

I’ve found that my lights tend to go from 4.2v to about 4.0v pretty fast then spend forever going from about 4.0v to 3.8v. Then once it gets to the 3.7v range it’s weak and the voltage starts dropping pretty quick again.

When it comes to boost drivers, as the voltage drops, the driver has to pull more amps from the battery. There is always going to be a cutoff point where the driver designer has to limit the current to keep from burning up the driver.

Some boost driver lights will give higher output, let’s say 3,000 lumen, but they will have to reduce the output sooner. So they may loose turbo at 3.9v for instance.

The Acebeam EC65 is a boost driver light that does a measured 3750 lumen, but it can only do it for about 1 minute! After that, the factory battery voltage is too low (too much voltage sag) and you only get a reduced output of 3000 lumen. This is an extreme example.

The SP33 is a more conservative example that does 2200 lumen and can maintain this all the way down to 3.70 volts. I like this strategy. It makes for a much more practical light.

Good explanation. Now I get it.

A couple people have tried the Sofirn 26650. Their 5500mah model seems to measure closer to 5200mah and their 5000mah seems to measure closer to 4700mah. This was measured on typical battery chargers that measure capacity so not super exact.

It seems like the more current reviews show the capacity closer to spec.

Their internal resistance is a bit high. They are not high drain cells and don’t produce high output in FET driven lights. Since the SP33 seems to have a set voltage that determines when it looses Turbo mode and not a set current limit, I’d say their 26650 cells should be fine to use in the SP33.

I wish we had some better reviews of their batteries.

Maybe I should buy 2 of the 5000 and 2 of the 5500 to test out?

Thank you for replying.

I was after a runtime on Turbo but realized I could test on my CBA. At 5.80A my 26650HC2 5000mAh runs for 12 minutes to 3.7V.

What current is it pulling at 3.7V though? I’m just trying to get an idea of runtime.

It pulls the same 5.8A from the battery from 4.2v down to 3.7v. This boost driver is not like the typical boost driver.

Thank you.

I’m getting a better understanding of how the driver works now. It’s quite a decent driver when comparing to Direct Drive. At 3.7V on direct drive the Turbo may only be outputting 920 lumens for the High mode on this boost driver. Just because you can access Turbo on a Direct Drive doesn’t mean it’s outputting that brightness. At least you know on the Boost that it’s outputting a set amount or close to it

I might get a sample light and see what I think

Correct.

A FET driver, or direct drive, connects the battery directly to the LED. This means the output slopes down as the battery voltage drops.

With a boost driver, the output looks like steps. It gives steady output to a certain voltage or current, then steps down to a lower, but steady output.

They each have their pros and cons.

A FET driver is capable of higher output initially, but then steadily declines. It’s easier and cheaper to build, but requires the right battery and emitter combo.

A boost driver can have a lower, but steady initial output which can be set at the factory. This means less heat and less battery drain. It’s more expensive and complicated to build, though.

You can’t even run an xhp50.2 with a FET driver. It will draw too much power and burn itself up. With a boost driver, such as with Lexels and Richards (MTN E) boost drivers, you can set the current limit for the emitter by changing resistors. Let’s say you want a 3A turbo limit for a xhp50.2. That would probably draw 7A to 8A on the battery. As battery voltage drops, the current will go up (in Lexels and Richards design). Then say at 15A on the battery, the driver will have to step down the output to keep from burning itself up.

This lights are lack of inventory in our factory warehouse and when it is restock we will send the batch to amazon us. We will let you guys know when it is available on amazon and offer a nice price at time time. :smiley:

Planning to install emitters XHP50.2 5300k or 4000-4500K?

Great news Tracy… Looking forward to purchasing SP33 through Amazon US ! Thank You for the update :+1:

Maybe I should just cancel the order I placed for this light 7 weeks ago from your Aliexpress store and order it from Amazon.

Sliced my dome off today trying to warm up the temperature . Only slightly warmer than it was. Any tricks?