I have now decided to keep them, and maybe take wight’s advice and get into flashing.
It looks way over my head. But so was swapping a driver a few weeks ago 
Good call! Lots of folks in Hoop’s thread would be happy to tell you that it’s definitely not over your head.
I suggest LED Flashlight-INTL Outdoor Store
I run my 219C with that driver and this baby is bright
Mike
I think people worry waaay too much about regulation.
Almost all single li-ion drivers are linear drivers, so they only regulate while there is high enough voltage. The only way to get better regulation is a buck/boost style setup, but Zebralight and Armytek are pretty much the only people who do this, and it’s not something you can easily buy as just a driver.
You want a current limiting driver for the 219C. Otherwise they draw too much current from a decent battery. They have a very low Vf, that’s what keeps your output pretty constant to quite low battery voltage levels, without a buck/boost circuit.
I have measured a triple 219B-V1 (which also have very low Vf) with a 105C stacked for 5.08A at exactly 5.08A with thin DMM probes. Output is 1300 lm with battery at 4.2V and 1200 with battery nearly empty.
With a single 219C, you don’t want your current draw go past 6A, but that’s what’s gonna happen with a FET-driver and decent battery. Stacking chips on a 105C is they way to go for these low Vf emitters, IMO.
Yes, the 219C has a very low forward voltage. You probably want to regulate the high mode unless you’re running 3x nimh or a lifepo4.
Not the cheapest and not from Mtn electronics, but Led4power’s LD-2 driver looks like a great option for the Nichia219C. I just ordered one myself though it hasn’t arrived yet. The high mode has essentially unregulated DD/fet performance but it is limited to 6A by default so you wont blow the led.
Otherwise going with a Q-lite/Nanjg and re-programming it just how you want it as far as the modes go seems like a good option.
Chouster and Hoop hit the nail on the head. I haven’t played with the 219C yet but the graphs are crazy and regulation is clearly recommended.
If absolute maximum battery life is desired the 219C may even have a low enough Vf to make a QX9920 based buck driver worthwhile. In fact, I think it would be worthwhile. The LD-29 is not QX9920 based and might still be a good choice due to the 219C’s very low Vf. I think that the “current setting” procedure for the LD-25 also works on the LD-29. It’s worth playing around with, but a QX9920 based driver such as the ones seen in the Thorfire JM07, Solarforce dropins, the Jax Z1, and many others seems like a safe bet. IIRC it requires approximately 0.2v of overhead.
Thanks for all the recommendations, guys. 
Hoop, the LD-2 you suggested looks interesting. It’s unfortunate that it exceeds my budget.
wight, I’ve also considered using a buck driver. I actually have several old XM-L Solarforce dropins, but their drivers have very noticeable PWM. Even if they didn’t I doubt they are the current ones used in their XPL and XM-L2 dropins.
chouster, that’s some incredible performance. Perhaps I should also consider a triple with the 219C. I should connect them in parallel right, not in series?
It looks like the linear 7135 drivers are the best available option for me.
I’d be surprised if SF has changed the driver they use. They aren’t exactly all about innovation. 
Maybe people do worry waay too much about regulation.
I do not.
I was just trying to answer his question.
I think that it’s often worthwhile to point out what Chicken Drumstick was getting at (just not in this case). Often folks do worry too much about regulation. The user often can’t tell if the light is tightly regulated or not and sometimes we can do a good job without obsessing over regulation. In this case both the runtime and the LED choice ensure that unregulated is unsuitable for the application.
But the PWM on all the ones I have is very noticeable and unbearable.
I do have some old nailbender dropins that are PWM free…
Yes, parallel. With 3x219C D280 and 5.08A driver (2,8A nanjg 105C+ 6 x 0.38A AMC stacked) you should see about 1600-1700 lm and quite low drop in output with decreasing battery voltage.
Along with output I think that would depend on the kind of beam profile are you looking for.
If you learn how to piggyback an ATtiny you can probably add LVP and fix the PWM. Otherwise it sounds like the SF drivers are out.
Nailbender dropins were typically DD IIRC, so those do not help you.
With a triple buck regulation should be even easier and linear regulation will be harder.
In a DD situation with PWM “regulating” output, what happens to voltage level between the FET’s drain and Batt+ while in the low modes?
I guess what I mean to ask is, does voltage drop due to lack of “pressure”? This is something I’ve been wanting to measure for some time now. Just wondered if anyone knew off the top of their head.
Is it like a voltage divider where voltage is dropped because only so much current is allowed into the divider and some is allowed to leak out?
This is subjective, but I feel I get much longer run times from my DD 219C lights than I would if they were linear regulated. Wouldn’t the 7135’s be “burning” off the excess voltage? I’ve also heard of people achieving higher output levels by using higher than Vf voltages combined with PWM to prevent blowing the LED. I haven’t read the actual work. Just have heard of such work.
Personally, I would just go DD and use PWM to achieve long run times.
In order:
- Interesting things. Do you have an oscilloscope?
- Linear drivers (including 7135’s) do “burn off” excess voltage, but what’s important is this: [LED (Vf)+7135(Vdrop)]= wattage pulled from battery. Say 1 amp, regulated for a hypothetical example… [(3v)+(1.2v)][1A]= 4.2W… now do the same thing with DD… (don’t forget that the cell voltage will sag to meet LED Vf and current will rise) The result is not pretty! Clearly DD will last for much, much, much less time.
- Achieving high output levels with higher voltages and PWM definitely sounds like a recipe for popping Cree LEDs to me. The only time LEDs typically handle a higher pulse is at something like 10% duty cycle or less… which is not brighter at all.
Thanks wight.
- I have an surplus property purchased oscilloscope. Not sure if it works properly yet as I still have to learn how to use it. Someday, I will poke around to check the above.
- Are you talking about low modes in your second bullet? I and others have been DD’ing 219C’s with high drains for awhile now. Even though I’m anal about my thermal path, I’m sure it’s still pretty hard on those little 219C’s. So far, though, they are doing great. My little tube light F35 gets the most use. Granted, I don’t think I have resistance completely eliminated as I think I have very short 22ga leads in that. The rest of the resistance is about as low as you can go in a light. I only hit 7.2amps at startup. I’m just not really concerned about long life for my personal flashlight LED’s. I rather have the convenience of max output without a bunch of 7135’s. Also, I just don’t use high and turbo modes much (but I like having them available).
- I agree with your 3rd bullet too. Just heard someone was supposedly getting good results with it.
My second bullet is in reply to your “longer runtime in DD than linear regulated” concept, which is certainly way off-base IMO. It looks like you interpreted what I posted as a warning against DD - this was not the case. It was simply me stating in strong words that DD will get way, way, way less runtime than regulated with this LED (and many others).
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The 7135 will “burn off” whatever voltage is required to get the “correct” voltage to the LED. So to get to 1 amp (for example) the LED needs to be seeing 3v. We’ll just say that our battery maintains 4v under a 1A load, so there is a 1v difference.
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The 7135 burns off (1 amp) * (1 volt) = (1 watt) as heat. The LED burns off (1 amp) * (3 volts) = (3 watts) as heat and light. Our total energy dissipation is (1w)+(3w)= (4 watts).
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In DD the LED burns off whatever the battery can provide as light and heat. We’ll just say that our battery maintains 3.6v under a 5A load.
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The LED burns off (5 amps) * (3.6 volts) = (18 watts) as heat and light. Our total energy dissipation is 18 watts.
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In this partially-made-up situation we are comparing 18W in DD generating ~1200 lumens with 4W in Linear generating ~400 lumens. We can clearly see that while linear “wastes” plenty of energy it allows for much longer regulation in “High/Turbo”.
Now let’s extend that exercise! What if we say that we’ll reduce our PWM on the DD light to fix the situation? OK, 400 is 1/3 of 1200 so we’ll reduce our PWM to 85/255. Now we’re looking at 18W divided by 3 = 6W. Oops! That’s a lot higher than 4W. Realistically our battery should sag less, so we’ll turn PWM down even more to get to 400 lumens, reducing wattage… I’m not sure exactly where that puts us, but I seriously doubt that it beats our regulated 4W in terms of dissipation… and the other disadvantage is that if for some reason a person wants reasonably constant light output they’ve got to cycle up through a big mode group (7 modes instead of 3 for example) as the battery discharges. With the regulated light they can pick a mode and stay there indefinitely.
In our 1 amp example it’s also important to note that 1 amp is approximately 3x7135, so we’re dissipating 1/3w in each 7135. This is not negligible. The driver should be clamped into a mounting area to dissipate heat. If not (for example if the driver is “floated”) the 7135’s will “self protect” and output will drop.
^
I trust your thoughts on this matter more than mine. My subjective experience tells me otherwise, but I also have a lot of faith in your knowledge base and logical thought process. So I will assume you are correct in your above statements.
EDIT: With that said, I will stick to my approach as I am very happy with it. I don’t ever find myself needing to change modes to compensate for declining output. Certainly no more so than with linear regulators. With the Attiny 25 at the speed I use, even the low modes seem rock solid. Maybe just the power of suggestion, but I find that the light seems much more pleasant and “real” with the faster Attiny’s. I know, I know, we shouldn’t be able to detect it even at the slower 13a speeds.