can I run a xml2 with a Fet17dd zener mod for 2x 18650s ?
For a Split second—I guess you’re asking if you can run a XM-L2 with one cell —right—good question
I want to build a light that can use two cells but don’t want to build a xhp or mtg2.
It’ll poof quicker than you can hit the switch.
Well technically you can, but 8.4 volts will fry them without some serious resistance. If you had low amp batteries and a ton of very thin wire you could do it.
It would also be possible (I think) to build a firmware that leaves the “high” mode off of the driver. I have my doubts that this would work well at all though and you would have to match the batteries and wire resistance together along with the code. For instance 1% 10% and 30% then leave out the 100. That would work (I think) as long your got the right and didn’t go and put higher amp batteries in. You would probably go through a bunch of emitters before figuring out the right combination for the light though. This would still leave you using PWM for your “highest” mode though. You would also be stuck using the same battery type over and over. It also wouldn’t be like a regulated driver, the modes would drop along with battery voltage. Again I don’t even know if this would work for a fact, just a possibility.
Oh and your other alternative is to find a light where the batteries are run in parallel like the ZY-T08. Side by side batteries will leave the voltage at 4.2 volts and you can run that with a zenor mod as long as the emitter is on a noctigon or sinkpad.
something like this but with more amps… 3a would be nice
http://pages.ebay.com/link/?nav=item.view&id=131237426446&alt=web
Like this one: lck-led.com - Informationen zum Thema lck led.
Got it myself with 2 18650 - works great.
I have seen setup like this before: Single XP-G2 + zener modded Nanjg 105C driver + two 18650 in series, and the outcome didn’t turn out well. After running the light on high mode for about a minute the LED started to flickers due to driver overheating.
Nanjg 105C and BLF17DD drivers are not buck drivers, but they are just linear drivers, meaning that these drivers cannot step down the voltage. So when your input voltage (8.4V) is significantly higher than the output voltage (3.0~3.8V) the “excessive voltage” - or more appropriately the excessive power will be wasted as heat and something might be burned. Not a good idea, really, so using a buck driver is your only choice in this kind of setup.
But using zener modded Nanjg 105C or BLF17DD to run a 6V emitter like MT-G2, XHP-50 or XHP-70 is fine, because the input and output voltage difference isn’t that much anyway.
I am just trying to build a light with two 18650s with a xml2. I have a p60 that allows up to 18volt input.
That’s a buck driver and it’s what would work correctly for you. Keep in mind the size of the driver when looking for the correct one and the output. Here is a list of the Buck drivers at RMM’s site, he is a great guy and ships super fast. He also has the emitters on noctigons so that if you want to go with much higher amps you can do so without frying them.
look at my post above yours.
You are building a P60 dropin for a two battery light? If that is correct then it’s the 17mm driver that you need.
hmm that $18 driver version is kind of pricy they rest will not fit a p60…
It’s hard to find a smaller buck driver. I know they make a bunch of them and put them in lights but they don’t seem to sell them retail. I looked around for you at a couple places that I buy drivers from but nobody seems to have them in stock. One nice thing about the $18 driver is that he will program it for you so you can pick your own modes. He has to make these drivers himself so the price is really pretty good considering his time involved. Still I know what you mean, it’s a lot of money to drop into a light just for a driver.
That's why the MTN-MAXlp was created. There wasn't ever a 17mm buck driver that would do more than ~1A and still fit in a P60. There was also a lack of high-powered buck drivers that could fit in 17mm lights like the UF-1405.
If the price is too high then you can just get the PCB and build your own. I posted the PCB, parts required, etc., including the board needed to program the MCU on this forum. Here is the post that will tell you pretty much all you need to know.
Another alternative is to take a driver and modify it by adding a resistor to it. This one looks like it could be modified. I have modded a ton of drivers but I’m really a hit and miss kind of guy when it comes to modding buck drivers for single emitters.
If you already have a driver in the light and just want more amps you could take a picture of it and maybe someone can help you out. If it’s one I have worked on I might be able to help myself. I would try and mod the driver you have if it was me, but then again I have a large box full of drivers that I have killed too. I have killed at least a hundred emitters too! So there are people here that know a lot more about them, at least how the electronics work.
This really looks like you should be able to stack a resistor on top of the R150 and get more amps, but I haven’t worked with it.
Right on and it explains why I have a bunch of lights that I modded to take a single battery. It was easier than finding a buck driver for them. Now that this is out I’ll probably go back and mod of few of them with it. Thanks for the link. I’m just getting back to modding and need to place an order with you soon. Once my shoulder is healed up I’ll be hitting it hot and heavy again. I have a bunch of lights for other members that I need to get caught up on. Your site is really a godsend and I’m not kidding either!
I have three projects
- Have a UF-V8 2x18650 want to put an xhp70 in so I need a (8.4v/6v driver hopefully with out noticable pwm does not need to be super hot, would like ramping or lots of levels) and a copper board for it.
- a 6v driver for a s7 clone. ( do we have access yet to 6v boost drivers) aka single cell like the jm35?
- “regular” driver for the other s7 for a 3c XML emitter
Any thoughts
Non need to be fire breathers I am more concerend that”high/turbo” is actually usable for long times.
what about running a 6v XM-L2 with DD and some tame 18650’s?