I was thinking of USB powered lights plugged into USB power banks, but many of those power banks wouldn't output enough current. Plus there would be lose of capacity burned up in boosting voltage to 5.0v. I abandoned the thought.
-Garry
Good point, they won’t output 3A to fully drive the LED
That LED says 1.7A and also says 10W (which would need 3A), so i’m assuming the actual draw is 1.7A, but you are also correct that we don’t know the inefficiencies in the setup
If i had $16 i would try it, i already have the ML-102 for charging
Oh, sorry. That listing only had one item when I bought it. I got a 3xAAA one.
It was cheap, and I wouldn’t trust it on bumpy roads (its angle mechanism is weak), but it was a fun way to see far away. Also very effective for making sure cars see you, since if you aim it at a car it’ll appear brighter than a car’s high beams.
I don’t see much point using a zoomie headlamp in its wide setting while biking… it wouldn’t throw very far at all in that mode. I was thinking more of using it zoomed in to a narrow beam, which would have great throw but no spill at all. A reflector-based light, OTOH, would give you both spot and spill — less throw than a zoomie, but you’d get some nice context around the hotspot.
The best type I’ve used is a reflector-based headlamp (ZL H51), but it was a bit pricey. A spot+spill beam is nice because the spill illuminates things up close while the spot lights things up at a distance. A zoomie, OTOH, can work near or far, but not both at the same time.
This might be a stupid question, but I’ll ask it anyway. Don’t all lights have reflectors, regardless of whether they have a zooming mechanism or not?
Nope. Some lights (especially aspherics) specifically avoid reflecting any light, and coat everything inside (except the emitter) with matte black paint. This helps avoid weird rings around the beam while zoomed to a tight spot.
For example, here are a couple SK-68s which didn’t prevent reflections well enough, so they have rainbow rings around the hotspots:
Oh, and here’s what it looks like if you use an aspheric lens and a reflector (orange peel reflector):
A bit weird, no?
i like that, a bit of free spill from otherwise wasted lumens, and the pattern is fun too
which reflector and light is that?
It’s a Convoy S3 with XP-G2 (sold that way from Intl-Outdoor), and I took the aspheric from an Ultrafire 838. It was just kludged together for a quick test:
i wonder if that aspheric is available on its own
Thanks a lot for the clarifications. It makes sense now. The reflector+zoom combo does look strange.
So excited. They are here!
I was expecting the flashlight today as tracking was showing the in Pittsburgh already, but magically the batteries were delivered today as well, even though they were still showing up in the Kuala Lumpur airport. 24 days for the Convoy S2 and nitecore I2 charger from fasttech and 23 days for the protectec 3400 mah panasonics from wallbuys.
S2 looks and feels great. My DMM showed 3.6 volts for the cell. It’s currently sitting in the charger. Can’t wait to use the light for my ride home from work today.
Thanks to everyone for all the suggestions.
I’d love to hear your thoughts after you’ve tried using it. 
I’m pretty happy with my 2100mA T6-3C S7 for biking (same reflector as S2, IIRC), though the stainless steel body doesn’t dump heat very well. It can only maintain “low” in stagnant air or “medium” while I’m biking, with “high” reserved only for short bursts. It looks nice, but aluminum would be a lot better at shedding heat.
That’s a good combo you got there!
I have used the light for three days now on short commutes, about 10-12minutes each. I have been running it on high and two days ago when it was –8C the light didn’t even get slightly warm. Today the temp was 13C and the head got slightly warm at the end. I have the 2.1A, AMC7135*6 version.
I find it great at slow to medium speeds and a bit lacking at 18+mph. At higher speeds I look further ahead on the road, and if I tilt the light up a bit to illuminate further ahead, I feel like it I could use a bit more throw.
One small thing I didn’t like is that the end of the spring at the head is not bent inwards, so when I tried to screw it on while the battery was in the light, there was some resistance and it scratched the nipple a bit. The tip of the spring at the tail is bent inwards, so it rotates smoothly against the battery.
Overall very happy with the light.
I may try some kind of a thrower on my helmet and see how I like it. One thing I worry about though, is what that will do to the drivers when I term my head back to check on cars behind.
I have tried searching but haven’t been able to find an answer. What does the low voltage warning look like on Convoy S2 (from FastTech)? Does it give a warning or does it turn off the light? What is the voltage when this happens?
3V it switches to low and flashes once per second
Thanks!
Glad you like it. I can see it not having enough throw for you at higher speeds. I wonder if you should increase throw slightly to get a "best of both worlds" kind of light or if you want to keep the S2 on the bars and add a thrower to it (either bars or helmet mounted). I'd suggest the Convoy M1 for more throw, though many will recommend the Convoy C8 (I don't own either). Remember the larger the reflector diameter the more throw with less spill you'll get.
If you're ever coming over east I could show you a few lights to give you an idea. I also have a bike trail right down the road from my house capable of 20+ MPH speeds (though it's pretty unusable until Spring now). I have a KD C8 which will have about same output at the Convoy. I also have OP and SMO reflectors. Also have a C8 with an XP-G to show off difference from XM-L to XP-G. My intended bike light is sitting on my bench waiting to get modded (SkyEye F13 with NW XM-L2 on copper with Dr. Jones programmable driver).
-Garry
Fine tuning…
My S2 is bright; it lights up a block on high. I’m running at 2100ma and an OP reflector, but if your S2 came with an OP reflector, changing to a smooth reflector will help the throw and that might be enough.
The M2 would be the next step up with better throw and more spill than an M1 running solo…running two lights is the Cadillac way.
I like the M2. It’s the largest light I can EDC but any thrower in combination will get the job done.
If running with a single M1 or M2 you will want an OP reflector.
Interesting. I find that the medium setting is fine (~30% of 2.1A, IIRC) even when I’m going downhill at 30mph, and I almost never use the high setting. Most bikers around here still have oldschool lights made of several 5mm LEDs with a combined output of maybe 30 lm… so my ~225 lm medium mode looks blinding in comparison.
In any case, a head-mounted C8 would almost certainly give you enough throw. My main concerns there would be whether the beam would be wide enough to be useful, and if it might be intense enough to make your pupils contract further. Avoid aiming it directly at cars and you should be fine, because the spill isn’t intense.
I take my XinTD C8 biking with me, but I don’t normally leave it on… I just pull it out when I want to see something far away. A Convoy S2 XM-L at 2.1A should get somewhere around 4 kcd of lux, and the XinTD C8 gets more like 30 kcd or 35 kcd. Plus I hear I can get that up to 125 kcd with some mods, and I’m tempted to do so. When I’ve compared these against car headlights aimed at a wall, it looks like cars typically get around 3 kcd to 15 kcd. My car is toward the low end of that range, so most of my Li-Ion lights (even fairly floody ones) put out a brighter beam than my car. I’d like to get a lux meter though, so I can get some real numbers.