Group Buy: 46mm BLF SRK 7135 V2 - 32x 7135 Drivers
No Drama!
STAR Momentary Interface
i. What is the group buy for?
The awesome 46mm BLF SRK 7135 V2 driver. This driver was originally laid out by BLF forum member Mattaus and was later tweaked and upgraded by me. It is a great driver for those who are looking for a regulated drop-in replacement for their soup can-style lights by providing a good regulated current bump over most stock drivers, along with adding fast-PWM, low moonlight, and a better mode spread.
A bit more about the driver:
- 46mm with tabs that can be filed down for a tight fit in almost any soup can/SRK-style light
- What lights does this fit in? Basically, if your "soupcan" light uses four cells in parallel with a driver diameter between 43mm and 47mm you can make this driver work. The tabs and outside ground ring can be sanded quite a bit if needed to provide a tight fit. A few examples below:
- Skyray King and almost all Skyray King clones
- Supfire M6
- [Please post if you have another light and I will add it to this list]
- What lights does this fit in? Basically, if your "soupcan" light uses four cells in parallel with a driver diameter between 43mm and 47mm you can make this driver work. The tabs and outside ground ring can be sanded quite a bit if needed to provide a tight fit. A few examples below:
- 2mm PCB thickness (fits better in most soup can lights than 1.6mm PCBs)
- 32x 380mA 7135 chips
- Approximately 12.1A CC output
- Input Voltage:
- 1S (4.2V): This is how almost all soup can lights are configured from the factory: with 4x18650 in parallel and 3x up to 9x emitters in parallel. If all of your batteries face the same direction then your light is 1S.
- 2S (8.4V): Generally, 2S+ is only used in modified lights that are running 2S2P on the input to 6V emitters like the MT-G2, XHP50, XHP70, etc. This driver has an LDO option and LVP for 2S+, but you will have to convert your light. This conversion is usually fairly involved and not recommended for beginners.
- Separate 1x7135 channel for extra low and efficient moonlight
- Available with two different mode group options, both utilizing STAR momentary firmware:
- SRK Special: 7 well spaced modes with a great moonlight level
- Simple w/ moonlight: 3 modes with a great moonlight level
- Simple without moonlight: 3 modes without a moonlight level
ii. Why "No Drama"?
The reason I am calling this a "no drama" group buy is because there will be no negotiation with the manufacturer, no test samples, no waiting for months for it to be finalized, and most important---no unexpected changes in the product, pricing, or quality. In this case, Mountain Electronics is the manufacturer, seller, and shipper. All required components are already on-hand and ready to go.
iii. Timing, Terms, and Pricing
Timing
- The group buy opens February 3, and will close on Friday, February 12.
- Drivers will begin shipping immediately after the group buy closes, and all drivers will be shipped within 5 days afterwards.
Terms
- At least 35 drivers must be spoken for before the group buy can begin. --- WE HIT 35!
- Maximum of 100 drivers in this run.
- All orders will be placed on mtnelectronics.com for USA customers and international.mtnelectronics.com for all customers outside the USA.
- All eligible group buy participants will receive a PM with a unique discount code
- GROUP BUY PRODUCT LISTING LINK
Pricing
-
- 1 driver: $14.75
- 2 drivers: $14.25 per driver
- 3-5 drivers: $13.95 per driver
- 6+ drivers: $13.65 per driver
- These prices do not include shipping. Shipping cost will be determined based on actual package weight. Each driver weighs about 0.5 ounces.
Mountain Electronics : batteries, Noctigon, and much more! What's new?
Sign me up, qty 1 please
.
This is a drama free zone!
I like the driver, but is there still a SRK available that is of decent quality?
Put me down for 1
One for me.
- LEDs & Other Stuff - - UI CheatSheets - - CRX Flashlight Builds - - CRX Stuff for Sale -
I’d like to know this too. Can anybody make a recommendation? Link if possible!
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Well the SupFire M6 Richard sells is bout the best SRK. I got a FandyFire and another clone needing some upgrading, so not a problem for me. I'm not interested in finding/buying any others, mainly because of exactly these unknown quality problems out there.
Oh, I was unaware that the Supfire M6 was a SRK clone. I thought it was a different style light.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
The M6 is a beast, for an SRK that is. It is one chunky monkey, and has a beauty of a driver retaining ring, so no glue needed to secure down the driver. Easy to mod, SS bezel, excellent pill top/shelf for mounting LED's on copper MCPCB's, etc...
I got one I did a ways back and it does like 5000 lumens w/UCLp lens, FET driver..
So, are you saying that this SRK driver board will fit in the M6?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
May be a silly question, but e-switch or mechanical clicky? Also what’s the voltage input range?
Either way put me down for one. Just trying to understand what I’m buying. Thanks Richard.
I'd say it is an upgraded version of the SRK, better in almost every way.
... The timing on this group buy is painful. I've spent waaaaaay too much on flashlights and parts in the last month.... But I'd really like to upgrade a quad, or maybe that M170.... Hmm. I'll have to think more on it.
A SRK style light uses an electronic side switch and four 18650 cells in Parallel, meaning 4.2 volt max. 7135 drivers are linear, meaning input and output voltage is the same.
I can attest to the fact that these are great drivers, if you want to make a 3x led SRK into a very bright light with about 4 amps to each led.
My PayPal address: oldlumens (insert the @ sign here) gmail.com
My YouTube Flashlight Video Channel
The BLF Modding Links Thread
I don’t doubt your information, but when I looked at this GB, I also wanted to know the max input voltage, went to the store and found another driver with a very similar name that stated among its features:
Richard, can you clarify?
Lazy-R-us
Sign me up for one please.
But, is there any way I can get just a “little” bit of drama? I mean, just a twinge of drama would make this deal absolutely perfect!
Aspiring Fhashlightaholic!
I think you two are saying the same thing. If you feed it with 3s 18650 you need to have a series triple on the output. That’s what I thought and I think you two have confirmed it. Thanks guys.
So another question, which is better: 3s cells and noctigon or 3p cells and noctigon?
An SRK has the batteries in parallel, 4.2v max. This driver can also be zener modded though, meaning it is still linear, but can be used in other custom projects to use 2S or 3S batteries to power 6v led’s or other emitters in Serial.
My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03
Major Projects: Illuminated Tailcap, TripleDown/TripleStack Driver
This version actually has an LDO option on the battery side so it can be used with 2S configurations as well, with very low parasitic drain. I don't recommend using this with any 3S setups. I just updated the OP with this information.
@OldLumens: Justin, it is good to see you here! I missed having you around. I'm subbed to your YouTube channel and still watch all of your uploads.
Mountain Electronics : batteries, Noctigon, and much more! What's new?
E-switch. 1S or 2S, but hardly any stock soupcan lights use 2S (actually, none that I'm aware of).
Mountain Electronics : batteries, Noctigon, and much more! What's new?
Is this the same driver in the SRK you sell, or an option for including in it?
I’d like this in that, count me as yes for one driver. http://www.mtnelectronics.com/index.php?route=product/product&product_id...
Mountain Electronics : batteries, Noctigon, and much more! What's new?
Sign me up for two
3 please
It is done when it is done

How my BLF Specials generally work, please read before asking Qs
The Q8, Exciting a groupbuy for a Premium BLF special high lumens soda can light!
The GT, A BLF special GIGA thrower
The FW3A, a TLF BLF special small, elegant, powerful triple
Lithium Ion safety 101 important read
Sorry grammarlovers, I am a real King Typo.
Will this fit in the Ultrafire UF-T90?
EDIT1: I forgot, that’s a ‘clone’ so it’s possible that a different clone/original/whatever might have a different diameter driver. I’d be a little surprised.
EDIT2: As an alternative it might be worth considering the 9-amp driver shown off by Old-Lumens in this thread: Maglite Twins – Build thread. Beam Shots are up The stock driver would need to remain in place as a contact board. I think that the 24×7135 driver might be able to be installed directly against the back of the LED shelf if care was taken with the wiring. New wiring holes might be required. In any case the heat from those 7135s must go somewhere.
Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)
About that measurement, that is the PCB which is soldered to a brass ring. The brass ring could be tossed aside and the driver itself be used as the primary contact between the retaining ring and the head. I haven't done the measurements yet, but I suspect it wouldn't be too difficult to accomplish.
I'm also not sure if the UF-T90 is set up this same way in the driver area. Been a while since I researched that one.
Ok. Thanks for the info. I didn’t think of a slave board
Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)
Yep, well mostly. The retaining ring is separate, but going based off the pics (been a long while since I had it apart), the threads may run out before the retaining ring can snug down onto the larger diameter PCB by itself. Might have to get a little creative here.
The quad xml2 handle is actually the light I mentioned earlier 'quad' that I was contemplating putting this fantastic driver in.
Put me down for 1, thanks
Sign me up for one please.
Thanks
Pages