Review: Quad SST-90 / Quad-26650

This is a quick review of my new camping / emergency / zombie apocalypse flashlight. (Not likely an "under the sink repair" tool)



I purchased this from a fellow on CPF, who despite the somewhat odd and initially off-putting forum name ("vesture of blood" eek) was actually a huge pleasure to deal with. Again, notwithstanding the somewhat terrifying forum nickname, I wouldn't hesitate to recommend his flashlights in the future.

The price was actually fairly good in my mind. I realize that some of the components are generic. For example, the reflectors look much like those found in a typical XML. But I don't buy into the "let's pay three hundred dollars for a host, *just because it's trendy*" mentality of CPF anyway, so I was actually delighted to find someone selling basically exactly what I cared about - four really powerful emitters, heatsinked, in a big giant host. Knowing the price of the emitters and the mag body, I think more than half the purchase price was cost - which seems just about on par with the markup we often see around here on laser builds. So the price sounded more than fair to me.

This is a Quad-SST-90, and Quad-26650 (capable of 32650), direct driven build. If you know me, you know that probably the first thing I'll do is take this apart and try to fashion a current regulating driver. The LEDs are presumably in series, as the batteries are, so I'll potentially parallel the STCS2 ICs, or maybe kick it old school with a 12x AMC7135 setup.



But, for the time being, here are some photos AND a (completely non-scientific) comparison video against an XML and an SSC-P7. Thank god I'm not posting this review on CPF, because I'm sure I would be laughed away, much the same way we react here to new users who guesstimate a laser's power based on comparisons to other power-guesstimated cheap Chinese laser pointers from eBay.

From the original sales thread, a truck's 100W halogen high beams on the LEFT, the Quad-SST-90 on the RIGHT:



So, with no further delay, here's a video comparing this beauty to my cheap Chinese XML and P7 flashlights from eBay

NOTE: My phone didn't pick up the audio of my voice. So I'll need to explain what you're seeing:
- FIRST: An XM-L 18650 flashlight (running @ 2000 mA) is added for a control shot
- SECOND: An SSC P7 18650 flashlight (supposedly running @ 2800 mA) is added as a second control
- THIRD: While the previous two flashlights continue running, the Quad SST-90 is powered up. Over and over again. Teasing the camera



The Quad-SST-90 is so bright it causes the camera to adjust exposure down so far that both the XM-L and the P7 basically disappear.

Re: Review: Quad SST-90 from Matt

That is freaking awesome. I love these highpower flashlights. If you use it in camping whole apocalypse break loose. !!

rhd said:

This is a quick review of my new camping / emergency / zombie apocalypse flashlight.

Click to expand...

You forgot Vampires! Looks like it will stand in for sunlight quite nicely.
Glad your adding a driver. Do update us please.

Have you measured current at the tailcap?

I would think that to add a driver you would need one more battery in there because it is currently being "regulated" by the voltage of the batteries being slightly less than it needs to run full power. The extra voltage of another battery will give you some room for the small v drop of the driver, allow it to run at whatever current you want to, and keep the current stable over the discharge of the batteries instead of it going down as the batteries drain.

benmwv said:

Have you measured current at the tailcap?

I would think that to add a driver you would need one more battery in there because it is currently being "regulated" by the voltage of the batteries being slightly less than it needs to run full power. The extra voltage of another battery will give you some room for the small v drop of the driver, allow it to run at whatever current you want to, and keep the current stable over the discharge of the batteries instead of it going down as the batteries drain.

Click to expand...

If you look at the PIV curve:

3.1V = 2.5A
3.3V = 3.5A
3.5V = 5.5A
3.7V = 8.5A

I don't know what the limiting factor is, it's pretty close. But if I was going to introduce a driver, I'd probably try to target ~4A or 5A.

Either way, you'd be looking at around 3.4V of drop per LED. I probably never discharge cells below 3.5V, so that gives me cumulatively about 400mV to play with. There are a lot of good linear drivers out there, but I'd probably just do a 12x AMC board, for it's 100mV dropout.

As an old CPF member, and new laser forum member...I'd suggest running the light direct drive as designed. Direct drive is actually easier on the batteries, and gives a long runtime- since the light output tapers off as the batteries weaken. Most of the newer lights do use a driver to control the output- but the massive current draw of 4 SST90 LED's will demand a very heavy duty driver. This will make a simple reliable and powerful light much more complicated and failure prone. I realize that for some members the challenge of improving a product is worth the risk. Good Luck!!

rhd said:

If you look at the PIV curve:

3.1V = 2.5A
3.3V = 3.5A
3.5V = 5.5A
3.7V = 8.5A

I don't know what the limiting factor is, it's pretty close. But if I was going to introduce a driver, I'd probably try to target ~4A or 5A.

Either way, you'd be looking at around 3.4V of drop per LED. I probably never discharge cells below 3.5V, so that gives me cumulatively about 400mV to play with. There are a lot of good linear drivers out there, but I'd probably just do a 12x AMC board, for it's 100mV dropout.

Click to expand...

Ah ive never seen the piv for sst-90's but for some reason I was thinking that they had a higher vf than that. I though I remembered reading they averaged around 4v, and up around 4.2 at 9A. Not sure where I got that :thinking:

With a 3.4v drop per led it makes a lot more sense.

But that has me wondering, how much current are they using in direct drive? Must be pretty high with full batteries.

And @ light1, I would imagine that having them current limited to 4-5A would be much better for the batteries and led's than just letting them draw however much current they will take at a given voltage. Plus amc7135 don't really involve any extraordinarily complex circuitry at all, so they shouldn't be a point of failure :beer:

Is anyone else having trouble seeing the video?