Soon I will have all required parts for a triple 219C. Since I like the A17DD FET+1 - wrote my own firmware meanwhile - I would like to use this driver (single cell). I know about the low forward voltage of the Nichias. Does anybody know what will happen if I put a Keeppower 2900 (protected, NCR1865OPF inside) in my light? Frying the LEDs, or 10 amp protection steps in? What’s about LG HE4 and other high drain cells?
I also have LD-2, but I prefer my own firmware.
I haven’t done this, but I’ll postulate: nothing will fry if you’ve got good thermal paths. Protected batteries are less commonly used with FET drivers; people tend to use high amp cells like the Samsung 30Q, or the LG HE4 like you mentioned. I doubt a single protected cell will actually push 10 amps, but if it did, of course the protection would trip. A high amp cell may deliver over 10 amps which would be ok if you’ve got good thermal paths, though the light will get hot very quickly. It is definitely bad to feed over 6 amps to a single 219C, but with a triple and a single cell, you’d have to be pulling 18 amps for this to happen, and I don’t think it’s going to pull 18 amps from a single 18650 cell. Others may add clarity. Also worth mentioning… make sure there are no dust specs on your led domes or they’ll burn. Clean the domes with alcohol before final assembly.
I don’t know about the protected battery, but with a high drain it will be fine. I used a 30Q with my triple 219C and it pulled over 10A (Max my meter could read) and the LEDs did fine.
I’ve tried Nichia 219C in a small triple and wasn’t that impressed. Drew more current and got hotter faster than triple XPL-HI, while producing less lumens. Also, unlike the older Nichia 219B, the 219C’s tint and CRI weren’t noticeably better than XPL HI 3D.
Personally, I think Nichia 219C works best in small single-cell lights powered by 1x10440, 1x14500 or 1x16340. The lower Vf of the 219C compared to XPL HI makes it a good choice for lights with very small batteries. But for an 18650 light or a triple emitter pocket rocket, I’d go with XPL HI over 219C every time.
Thanks for the responses, I expected much more than 10 amps with high drain cells. With my triple XP-L HI I measured already 12 to 14 amps with LG HE4, but since that light is my EDC (until I build the triple nichia) I feel safer with protected cells. The mentioned Keeppower is really good for a protected cell, it delivers up to 9 amps and works flawlessly in my XP-L HI triple.
The protection will stop you.
Three 219C have 3.3 V_f at 10 A. Your Keeppower 2900 could do that for 6 minutes and give you almost 3000 lm. But the Nichias won't stop there and the protection will kick in around 11 A.
You need a driver for 10 A. Use thinner cables. :D
No danger for the LEDs though.
A higher drain cell like the Samsung 30Q could do 20 A at 3.6 V_f for 30 seconds. In theory that could give you the maximum of the three Nichias with 3840 lm but I have not seen a load graph for that cell for more than 20 A. Maybe it will just fry the LEDs and go to sleep.
In a real flashlight both cells might work as the overall resistance may be high enough to limit the current. Or the rising V_f from the heat.
Yea it should pull more than 10 amps with a high drain cell. More than 18 amps? I don’t know but I have my doubts. Choosing the right cell would achieve the optimal result I’m sure.
I concur with what Firelight2 said; a single 219C works great in lights with smaller batteries.
LED forward voltage drops with increased temperature.
As far as the cell is concerned, Dale has had a light pulling over 21A from a single high-drain cell. I think it was a triple of some kind, but I can’t remember the details. A quick search will find the reference for you, but I’m too lazy right now. If you wanna see it, you can do the search yourself. :innocent:
They work great in small triples (a Reylight Ti 18350 in my case) but on an 18650 with all resistances in the system removed, you may get more than 16A on a high drain cell (DBcustom got 21A in a 219C quad) and at over 5A this Nichia is not very efficient.
Oops. That explains a lot. :person_facepalming:
So I have 2 options:
- insert a high drain cell and use the springs as limiter (and fuse),
- use a short tube (S2+) with Efest 18350.
I think I’ll try both.
I have never stacked 7135 up to now - is it reasonable to stack 12 or even more 7135 to qlites or 105C? I would really like to have a driver with Attiny, limited to about 9 amps.
Which cell do you use and how many amps do they pull?
You have more options than that. If you match the right cell you’re going to pull the right amount of amps when it’s fully charged. You don’t have to use a 30Q 18650, you could use something with a bit more internal resistance.
Yes you can stack 7135’s on a Qlite no problem. 12+.
Any recommendation for about 10 to 12 amps? My 18650s are mostly protected, don’t have much experience with unprotected cells.
You can also just use a lower drain and/or higher capacity cell. An unprotected ncr18650pf would be a good choice for example.
I use a lila Efest IMR18350. I just measured the current at 10A. But there’s something wrong, I get 1800 lumen at start-up while that used to be 2700 (cometing down in 30 seconds to 2000 btw). Perhaps a 10A light should not be made from titanium after all :innocent:
Yea, titanium is an absolutely terrible conductor of heat. It’s on par with stainless steel. We’re talking slightly less than 10% of the thermal conductivity of 6061 aluminum.
Now 7075 aluminum is an alloy I admire. It’s almost double the tensile and yield strength of 6061, and it’s actually easier to machine. The thermal conductivity is only some 20% worse than 6061, so no huge sacrifice there.
Thanks for all help, I’ll report when I have done the build!
I’ve been too busy to build the triple up to now but I did some tests with a single 219C + A17DD in a S2+ with several batteries:
Efest Purple 700 mAh 18350 unprotected #1: 5.3 A,
Efest Purple 700 mAh 18350 unprotected #2: 6 A,
Keeppower 2900 mAh 18650 protected: 5.8 A,
Thrunite 3400 mAh 18650 protected: 5.3 A,
NCR18650B protected: 5.3 A.
Measured with clamp meter, springs not bridged.
Perfect EDC light.
One of the beauties of the 219C is that. even though it has lower Vf than most of the emitters we use, it can take the punishment if subjected to it. Sure, it’s life will be shorter, but most of us swap emitters as better ones come out.
I just avoid using the highest mode when the battery is fresh. Later, as the cell or cells have less charge, the light can still achieve high output due to the lover Vf. So compared to a bigger emitter, you have a longer high output run time (if you don’t run the light on high when the cells are fully charged). I rarely use high mode for more than a few seconds anyway. So low resistance and low Vf means more run time.