I’ve bought at least seven HX-1175B from lucky-guy2010. They are all good.
Maybe you purchased before the C’s started showing up. Hopefully he learned his lesson and ships HX-1175b’s going forward.
Hi, I’m new to this forum (first post 
so I didn’t want to open a new topic. This one is hopefully close enough.
I have 2xXML-U2+2xXPEn3RED light with a faulty driver, 1x32650 battery. I didn’t succeed in finding a new driver. So I want to find some kind of replacement/better one. I don’t need those 2red LEDs, so I want to bump up those 2 XML’s.
I had in mind SST-50 driver(ebay) (5A) and XML’s in parallel. There is only (I hope) one problem, XML’s need 3.2-3.7Volts and SST50 driver gives 3.7-4.2V. So I need a resistor, right? Only where to put it? Between driver and parallel connected XML’s or to mod resistor somehow (replace resistor somewhere)?
Any help would be appreciated
Hi nwonknu. You should be fine without resistors. A constant current driver will only provide the voltage needed by the emitters. For instance. If you had 3 cells in series (12.6 volts charged), you could connect 1 emiter, 2 emitters, or 3 emitters in series. The driver will provide the appropriate voltage as long as the cell voltage is higher then the emitter voltage requirements (plus driver overhead).
Hope that helps. Welcome to the forum. 
Wait a minute. Let’s see a link to that 5A driver.
The only 5A drivers I know of are buck drivers that need at least two cells.
3-18V
I’ve tried to find one that is more suitable for 1cell, but no luck.
Will this one work?
That's the driver I assumed you were talking about. I should have also said that it won't do too well on just 1 cell. I you should go linear or direct drive driver. It will work, but it won't deliver 5 amps.
EDIT: I struck out some wording above. I don't know if the driver works with one cell. The specs say it does. I meant to verify that quite some time ago, but I don't recall if I ever did. I'll try it out tonight and report back.
Could you please point me to something appropriate?
Most of the drivers I’ve found are max 2,8A.
Do you need it to be 26mm diameter only?
I have one of those HX-1175C's you linked to above. I haven't tried that driver with just one cell. I will try it tonight and report back on how much current it delivers.
If you guys are talking about the 26mm '3-18v buck/boost' driver, no, it does not work with one cell.
Actually, I’d like to see this light you’re talking about. How about a picture or a link.
Thanks, you’ve just saved me 12$!
Max dimensions of driver are 28mm x 12mm.
here is the link for f-light:
http://www.aliexpress.com/item/New-Underwater-Diving-Video-Flashlight-2xCREE-XML-U2-LED-White-Light-2-CREE-XP-E-N3/1891705512.html
EDIT: Would this one work?
http://www.fasttech.com/products/1612/10003372/1250101-v10-2745v-xml-t6-2-group-35-mode-led-driver-board
I don't know anything about that driver. Here are a couple threads on it. I haven't read them:
I’ve just now realized that I could fit two drivers inside this light…
I think my problem is close to an end