But I doesn’t quite like it due to lower efficiency because using constant current AMC7135 instead of buck driver (which more efficient across li-ion battery voltage)
My spec would be as following:
Medium size 1x 18650 torch (best if pocket fittable, something about 501B/502B size)
Using Buck Driver (reason stated above) with 1x 18650, 3 or more different brightness with memory (not ‘next’ type)
Single Cree XML T6 or higher bin, Cool White (preferrable) or Neutral White
Highest mode drive at 2.5A or higher. (More than 700 lumen)
Square thread or similar (provided durable and reliable)
Good heat transfers for sustainable ~2A operation without too hot (for hand and LED)
At least moderate grip (slippery is big problem)
Able to use unprotected flat-topped battery
Preferable gradual beam from center focus (some torch have really bad ratio of throw/spill) Good flood to throw torch is great addition.
Preferable no blinking mode(SOS etc), or switchable group like convoy.
Last and not least, not too expensive, since I’m using for maintenance purposes only.
Personally I simply wouldn’t care, it’s only a torch and a cheap one at that (but very good). Just buy it and be done, then by more torches and be even happier enjoying this hobby
BTW - isn’t a buck driver going to be more common in multi cell lights where you need to reduce the voltage? An XM-L2 will run direct drive off of a 1x18650.
If runtime is an issue just carry a spare battery. Or make sure you use quality batteries rather than crappy ones.
A SMO reflector will give the most throw, but you’ll get a more distinct difference between hot spot and spill (assuming it’s well focused).
If you want a more gradual transition between the hot spot and spill you’ll want an OP or even a HOP reflector. The flip side is you’ll slightly lose a few lumens OTF and have a reduction in throw.
You have a point there, but I just want to get torch closer to my ideal that worth the buck. (If possible before I decided)
I think direct drive XM-L2 at >4V is dissipating alot of heat, not so good and easy to manage.
Well, runtime is one issue, but not so important for me. Dunno why I just want higher efficiency, don’t like the feeling of wasting ~ (weird green thinking)
Thanks for the advise, but too bad I don’t see Convoy C8’s beam shot. but it have OP reflector, so should be good according to you. I think will order it soon, maybe tomorrow.
What is the distance range that you want to use your light? For close work (1-10ft) I would recommend a light with a small reflector, tube or P60 sized (35mm head). With lights that have a larger reflector you will get a very bright spot that makes it hard to look and anything around the spot in the spill area.
A circuit like you describe in the budget range will be hard to find, if you want to make yourself a light then a driver like the LD-29 in a Convoy M1 might work (I have not done this).
A Crelant light might have a good driver, here are some from aliexpress SD85 V6CS (C8 size)
An option out of the budget range would be the Xtar B20, reviews on this one are pretty good
Another thing to consider is reflector size. The C8 has a relatively large reflector. This is good for throw, but is more likely to produce a higher contrast between hot spot and spill.
A smaller reflector will be probably suit you more. Maybe take a look at the Convoy M1 instead. More pocket friendly, but I think the beam will be more to your liking if you want a smoother transition within the beam.
Your statement that a buck driver is more efficient than a driver based on 7135 chips is not true in the case of using one battery.
Let’s do some maths about the efficiency of a linear 7135 driver. Please follow me on this, I’ll try to keep things simple, you only need to know basic electricity stuff:
-XM-L voltage at 3A: 3.3V
-Battery voltage when full: 4.2V
-Resistance path in the flashlight: about 0.1ohms in the battery; About 0.1ohms for the other contacts and the switch. So a rough estimation is 0.2ohms of total resistance.
At 3A that means that you get 0.2ohms x 3A = 0.6V of voltage drop across the different contacts and battery resistance.
-> To sum up, in the worst case (with the battery fully charged) the driver gets only about 3.6V input… Minus 3.3V that means that about 10% of the energy is lost in the driver. So an efficiency of 90%.
The typical efficiency of a buck driver is 80-85. 90 if it’s really good but then it’s not in your low price range.
If you use lower modes, things can change a bit in the advantage of the buck driver, but not much…
Buck drivers are more efficient if you have 2 or more cells in series, as in that case a linear driver (7135) would have an efficiency of less than 50% while the buck driver still has 80-85%.
I can’t quite get the difference of it. It also doesnt state the driver it uses (buck or linear) Except:
Output slightly higher:extra 200mA consumption
Beam seems a bit more focus, stronger hotspot. using SMO instead
More cooling fins, seems better heat management
Because my working requirement need both close (within meter) and far (12-24ft), so I prefer zoomie or smooth transition between hotspot and spill. very distinct (bright hotspot) makes close job difficult. So normally I use high mode on long distance, mid/low mode shine on close work.
I will have a look on those 4 light later and get back to you.
You are quite right, but most of the time i’m not using high mode. I would use them for less than 5 minutes in one time, mostly using mid & low. I could see the difference not much.
Another concern is heat management, how long Convoy C8 could withstand on high mode before temperature is detrimental ? (to life of LED and your Hand)
M1 seems to have smoother transition between hotspot and spill, also seems more heat conductive.
Does it have better heat management compare to C8 ? If yes then i’m going to take it.
Fasttech, banggood & gearbest all have Convoy series on sales, so which is the best ? (in term of money, reliability, etc)
Do Convoy line have difference of quality with different company selling ?
Only Banggood have XM-L2 U2 version, which is good and also cheaper. But delivery option not so good (slower) and doesn’t write about mode memory (dangerous)
Gearbest is more expensive, but better shipping option. Most important it mentioned : ” Mode Memory: No ” it scare the freak out of me.
Fasttech is quite in between all those, if got XM-L2 is the best. Only it got mention about mode memory.(all have memory or just FT?)
If you go with convoy the quality is pretty well standardized. A convoy from one place will be the same quality from another.
Most(all?) budget convoy lights (S series, M, C8 etc) have the same 105c driver. The mode will be memorized if you leave it on for a few seconds prior to turning it off.
All the shipping methods essentially boil down to where you are. Typically you’re looking at 2-5 weeks from china (their estimated ship time is a rough estimate) unless you pay $5-20 extra for expedited/DHL shipping.
All things considered I would go with banggood (Coupon: BLF), xml2 lots of tint options and cheapest price.
Not exactly all are same driver, the well-known C8 from banggood are ak47 instead.
Shipping method I’m not sure, because last time I got from banggood is about 3 weeks time.
Fasttech even slower via snail mail, but I just realise FT got Registered Air Mail stated 10 to 14 days.
Banggood registered airmail still same 7-25 days.
I forgot about the ak47! Afaik it functions the same as the nanjg 105c drivers.
The shipping deal is a tough one. I consistently get FT packages in 8 days via their registered USPS (free upgrade over $20+), but other people in the same country say it takes weeks until delivery.
You really only know approximately how long it will take after multiple orders using the same option each time, and even then it could hit a snag somewhere and take a month or longer. After so many orders online I really don’t pay attention to estimated times. I pretty much just worry about tracked/not tracked and the cost. Optimistic that it will get here within 2 weeks, but I don’t fret unless it approaches the PayPal deadline.
I have a convoy s8 that I use in my pocket, and on my bicycle handlebars. It spreads the beam out quite a bit, but I can see well even 15-20 feet very well in front of my bike, and the beam is still very good to use close up…I just normally use the low or medium mode close up.
It’s head is much smaller than a c8, and it fits in my pocket easily.
They are all using the same driver. Just make sure you order the version with 7135*8 if you want 2.8A on high. If you don’t like strobe and SOS you could also install the qlite driver from intl-outdoor. They are both (BG and FT) similar in shipping duration but you need to add the cost of registered airmail which is more safer or you could add another item to make it $25 for free registered airmail. One more thing don’t believe in their shipping duration quote. Sometimes you will receive the item faster sometimes longer.
It’s too bad you don’t want a driver with 7135, all the Convoy S line are excellent value and they still have my preference as I can rewrite their firmware to suit my needs.
I think then a Roche F6 would suit you, little more expensive than a Convoy, nearly all you want but no square thread (still very smooth) and it’s not as bright as a 8*7145.
