MTN Electronics: LEDs - Batteries - Lights - Chargers - Hosts - Drivers - Components - 1-Stop-US Source

So I just checked mountain’s website and I see an out of stock listing for a 17mm boost driver!

What, no link? Lol

17mm boost driver

This boost driver (input voltage is lower than output voltage) can drive 6V LEDs, such as the XHP50.2/70.2 from a single rechargeable lithium-ion battery at an output current of up to 4.2A. It can also drive a 12V LED, such as the XHP35, at up to around 1.3A. The MTN-BST2 uses a highly efficient synchronous boost converter squeezed into a tiny 17mm form factor.

Unlike most of the high power boost drivers out there, this driver can achieve a wide dimming range and utilize popular firmwares.

This driver takes up to 10 business days to be built, tested, and shipped. Your order will not ship until the driver is completed.

Battery & Host Requirements:

In stock form, this driver will pull just over 10A peak current, therefore a 10A+ continuous rated battery is required (unless you reduce the input current limit). The more voltage the battery can hold under load, the better the driver will perform. Your switch, springs, etc. must be able to handle the 10A+ input current; this means that you must have high performance or bypassed springs in your light.

The driver _must_ be soldered into the pill or held firmly in place with a retaining ring. This is required both for adequate thermal and electrical performance. If during use the light turns off and on, the driver is overheating and needs to be switched to a lower mode or turned off and allowed to cool. Continued operation at excessively high temperature will damage the driver (damage from excessive temperature will not be covered under warranty).


Boost Converter (input voltage must be lower than output voltage)
3V - 5.5V input voltage range (suitable for a single lithium-ion battery)
Designed to drive 6V LEDs, such as the XHP50.2 and XHP70.2 at drive currents up to 4.5A
Can also drive 12V LEDs, such as the XHP35 at currents up to around 1.3A
Output voltage range: ~6V —- ~13.8V
Output current range: 6V LED: 1A —- 4.2A
XHP50 / 50.2
XHP70 / 70.2
MT-G2 6V

12V LED: ~1.3A

Input Current Limit Option:

If you are running any battery that is not capable of 10A+ continuous discharge current, you must change the input current limit to a lower value.

~10.5A | 4.2A w/ 6V LED maximum recommended output current
~8A | 3.5A w/ 6V LED maximum recommended output currnet
~4A | 2A w/ 6V LED maximum recommended output current

Output Current Option:

The output current is set using one or two sense resistors. You can choose between any of the following output current limit options:


Firmware Options:

Currently only guppy3drv is available. We will have Bistro available as soon as we get it 100% dialed in.

  1. guppy3drv (click for more information).

2. Bistro

I’m hoping the 20-22mm versions will have a bit higher 12v output and support both 1s/2s but either way ill still buy one of the 17mm’s as is I think.

Yes, I’m surprised the 12v is not a bit closer to half the 6v output.

We know that a bigger size driver can do 12v up to about 3A, but I’m not sure if Richards will go that high. He may dial it back a little to get better reliability.

This is just the beginning. More is to come. :wink:

Richard is about to be flooded with boost driver orders once he lists them in stock :smiley:

Is there a reference you guys use to determine the proper output for XHP and MT-G2 LED’s. I mean, is there a good output to heat chart for each that shows how many amps it would take to blow an emitter?

I don’t want to be selecting 4.2 amps for a XHP50.2 when it can’t handle it. While I wouldn’t want 1A if it can really handle 4.0A either.

Check out these examples and look in each of their signatures. I like each member for different information so you should decide for yourself but they basically all test LEDs till they are almost or completely dead.




It’s best to just Google the emitter name and specs. Switch to images and look for charts. I keep a whole folder full of these charts.

For a 6v 50.2 and MT-G2, 4.2A is fine for both.

Just so’s ya know, Richard has tested this boost driver of his to death. That’s the way he does things, he won’t release it until he’s very confident it will work reliably. And he’s at that point now. So while we’re just now seeing these he’s been torture testing for quite some time and tweaking to ensure they hold up. :wink:

I’ve talked to him about these quite a lot and of course am as eager as anyone to get an order placed. I’m told “Soon”, and I believe they’ll be worth it.


I just ordered one. :wink:
23 more available.

The 17mm boost driver looks good, but I’m hoping the larger ones will have more power. I’m at a point in my flashaholism that I’m not satisfied with a reasonable amount of power. I need an impractical amount of power. :smiley:

Here’s some pictures. Hmmm, no Atiny85.

There’s not a big difference between 4.2A and 6A. So if you wanted a 70.2 in an S2+, 4.2A is still great. You’ll get much longer run time compared to using 2 x 18350.

Maybe you mean the 12v output? That I can understand.

Personally, I’m still waiting for the e-switch versions with ramping. :wink:

I just ordered a boost driver for my S2+ copper edition… I’m planning on using a xhp50 90 cri led that i have on hand for now for the build.

Be sure to post your beam shots and stuff with that LED. I ordered a 50.2 80CRI 4K one to try in a miniC8 OP reflector

Will do, I’ll report back once I have it put together. My led is 5k and the product code is XHP50A-00-0000-0D0UH250G. TA got his hands on some xhp50.2 4.5k 90cri leds that he is going to test on and I think he plans on putting up some for sale. I’m hoping to get my hands on a couple if TA sells it.

They are here:

Didn’t realize yours were XHP50 and not 50.2 I guess it might not be so comparable to mine. Still interested in your results

Also, I dont want to burst your bubble about that 4500K LED but expect a tint shift if you put it in an S2+, here’s are some beam shots of the zebralight 50.2 4500k 80cri:

Well I’ve used these xhp50 leds to make a triple before so I know I like the tint. The 50.2 leds TA has are 90cri and not 80cri, I’m not sure how much difference that’ll make when it comes to the tint shift. Plus I plan on using TIR optics or a Ledil Boom reflector for the light which should eliminate or reduce the tint shift.

Ordered a 17mm BST and there are now just a handful left… XHP50.2 J4 in a C8 with OP reflector, I hope to get a nice even beam out of it.

My wild guess is an ATtiny1616. Either way I think it’s the component on the bottom which could be nice.