Just can't resist ordering the BLF Q8.

[ImA4Wheelr]

@sb56637

@sb56637

I finally received mine today after some problems with the mail system. Wow! This thing is a real piece of engineering, and is a real testament to Thorfire and the thousands of man/woman-hours poured into it by the BLF team. I love the interface, and I can’t wait to test it in the dark. Machining quality is top-notch, clean reflector, well centered LEDs, and butter smooth threads. :+1: :+1: :+1: :+1: So that’s four thumbs up from me. (I’m all thumbs when it comes to manual work, which is why I can do that and still have enough thumbs left over to type this. )

When I tested it for the first time, I used new Samsung 30Q cells that I had never charged. I later tested them to be somewhere around 3.0V. I thought the light was pretty bright then, but now that I charged the cells up to 4.2V the light looks about 50% brighter! :sunglasses: I love it. My only complaint is that strobe mode doesn’t feel very bright. It might just be because the frequency is so high that the full brightness is never reached, or maybe it’s actually a lower power setting. I’m one of those rare few that actually uses the strobe fairly frequently to scare off nighttime prowlers and miscreants, so I’m probably the first to notice.

My wife and I also regularly use strobe mode. There is a very effective dual-frequency strobe on the Q8 that we love. It is the second mode in the strobe cycle. Once you get into Strobe mode, half click one more time to get into it. You have to do the half click pretty soon (< 1 Second) after getting into Strobe mode.

[djozz]

@ValuseekeR

One additional question I have though is that aren’t 18650s the same as what’s typically used in li-ion laptop batteries, powerbanks, cordless power tools, etc? Are the risks in flashlights using them just inherently greater due to the high discharge rates and temeratures?

No, the risks are just greater because in the usual devices the 18650’s are always packed in fixed packs surrounded by safety electronics that monitor the charge status, balance between batteries, and those battery packs will cut off when a worn-out battery is detected. In flashlights battery-monitoring occurs or not depending on which flashlight it is, but the monitoring is never as good as in the normal consumer devices. Still if you use quality batteries of main manufacturers you should be fine using them in flashlights.

[Lightbringer]

@zespectre

Because it is a relatively “high draw” light if you run it full out, you should probably commit the 4x 18650 cells to be used specifically with this light and not swapped out with others, especially with any single cell lights.

The reason, as it was explained to me, was that you want the cells to balance out as a set so that they will work optimally together. If you take one of those cells and run it with another light it can throw off the discharge characteristics and alter the number of charge/discharge cycles relative to the other batteries.

I’m probably going to get dogpiled on for saying this, but I wouldn’t put that much importance to that.

All the cells are in parallel. Let’s assume just 2 cells in there, a high-drain 30Q and lower-drain panny-B. In parallel, the terminal voltages will be exactly equal, whether switched off or going full-tilt. You’re basically crowbarring the cells together in parallel, one end the tailcap, the other the big honkin’ brass circle.

So let’s say you’re draining full current when switched on. The 30Q will drop to a certain voltage, but so will the panny-B. Even though the panny-B will sag a lot more at the same current than the 30Q would, they’ll naturally balance. So if the 30Q drops to 3.90000V at 10A, the panny-B will also drop to 3.90000V but at only 2A. The internal resistance of each will determine how much each one sags at a given OCV (open-circuit voltage) and current draw (I²R drop). Period.

Look up what’s a “load line”. Just like the volts-vs-rpm curve for a motor, you can know exactly how fast the motor will spin with a certain applied voltage, if you know exactly what the load is over the range of rpm. Where the 2 lines cross will tell you. So it is, each cell will have its own load-line as well, and will let you know exactly how much each cell will drop for a given current. When you can define the current of the LED with applied voltage, you can exactly calculate how much current each cell will supply, and how much current for each, and the voltage at the terminals.

So while it may be extreme, you can use primo 30Qs and VTC6es, in parallel with ancient laptop-pulls.

[Boaz]

@zespectre

I have a couple of lights where I stick a tiny little neodymium magnet to the top to make a “button” on the flat top batteries.
It works pretty well.

Magnets are just a bad idea . they are dangerous / move around and dent your batteries because they are usually much smaller than the surface they sit upon .The forces of pressure created by screwing down a tailcap can be pretty massive .
A solder blob works much better .So damn easy I wondered why I ever waited .Never seen a light that wouldn’t run on a flat top cell with a solder blob …
Too easy !

[RobertB]

@ImA4Wheelr

My wife and I also regularly use strobe mode. There is a very effective dual-frequency strobe on the Q8 that we love. It is the second mode in the strobe cycle. Once you get into Strobe mode, half click one more time to get into it. You have to do the half click pretty soon (< 1 Second) after getting into Strobe mode.

Lol… just pictured you and your wife with a bottle of champagne and your own private disco party

[ImA4Wheelr]

^

Upon rereading my post, I totally see that and worse.

[sb56637]

@ImA4Wheelr

@sb56637

@sb56637

I finally received mine today after some problems with the mail system. Wow! This thing is a real piece of engineering, and is a real testament to Thorfire and the thousands of man/woman-hours poured into it by the BLF team. I love the interface, and I can’t wait to test it in the dark. Machining quality is top-notch, clean reflector, well centered LEDs, and butter smooth threads. :+1: :+1: :+1: :+1: So that’s four thumbs up from me. (I’m all thumbs when it comes to manual work, which is why I can do that and still have enough thumbs left over to type this. )

When I tested it for the first time, I used new Samsung 30Q cells that I had never charged. I later tested them to be somewhere around 3.0V. I thought the light was pretty bright then, but now that I charged the cells up to 4.2V the light looks about 50% brighter! :sunglasses: I love it. My only complaint is that strobe mode doesn’t feel very bright. It might just be because the frequency is so high that the full brightness is never reached, or maybe it’s actually a lower power setting. I’m one of those rare few that actually uses the strobe fairly frequently to scare off nighttime prowlers and miscreants, so I’m probably the first to notice.

My wife and I also regularly use strobe mode. There is a very effective dual-frequency strobe on the Q8 that we love. It is the second mode in the strobe cycle. Once you get into Strobe mode, half click one more time to get into it. You have to do the half click pretty soon (< 1 Second) after getting into Strobe mode.

Ah, thanks for the tip! I never found the other additional strobe modes, the click window is pretty short. What a fun light!

[Aleister]

@Boaz

@zespectre

I have a couple of lights where I stick a tiny little neodymium magnet to the top to make a “button” on the flat top batteries.
It works pretty well.

Magnets are just a bad idea . they are dangerous / move around and dent your batteries because they are usually much smaller than the surface they sit upon .The forces of pressure created by screwing down a tailcap can be pretty massive .
A solder blob works much better .So damn easy I wondered why I ever waited .Never seen a light that wouldn’t run on a flat top cell with a solder blob …
Too easy !

A few years ago I had a moved-while-screwing-the-tube magnet short a Panasonic 18650PF inside a mechanical e-cig. In 1-2 seconds it heated up to to a point that I couldn’t keep touching it and I almost burned my hands while unscrewing the tube to open the circuit. What was going to happen next, I am not sure. Maybe just melt the e-cig, maybe vent through the vent holes of the e-cig and successfully launch it to outer space, maybe the vent holes wasn’t big enough and couldn’t prevent the tube from exploding. And these are my thoughts about only one “safe”, high quality, high-drain battery in an e-cig with vent holes. I can think of worse scenarios than that if using a flashlight with no vent holes, 2/4/8 18650s and, maybe, less “safe” cells.
So, yes, no magnets.

[zespectre]

Magnets removed.

I only did it with one light but that was obviously a very silly thing to do

I’ll be honest. I have NO idea why I ever thought that was a good idea. (DOH!)

[ValuseekeR]

Ack!!

Good: Banggood delivered my Q8 much more quickly than I expected.

Bad: They split my order, so I have the light, but no batteries or charger… :person_facepalming:

If the rest of my order doesn’t show up in a day or two I might be hitting up the nearest vape shop.

[nick779]

I impulsively ordered one of these too. Im a sucker for fast shipping too, so I paid the $10. Should be here in about a week.

[Zulumoose]

I have the light, but no batteries or charger… Facepalm

If the rest of my order doesn’t show up in a day or two I might be hitting up the nearest vape shop.

If you really are that desperate, buy one high drain button top cell, you can run the Q8 fairly well on one cell, you just won’t see the peak output.

[ValuseekeR]

@Zulumoose

If you really are that desperate, buy one high drain button top cell, you can run the Q8 fairly well on one cell, you just won’t see the peak output.

Yeah, might do that. I have a S2+ in the mail that I need a cell for anyway. I was going to use a protected cell in that one, but I’ll stop at the vape shop and see what they have if nothing shows up in today’s mail.

Not exactly desperate, wasn’t really even expecting to have it already, but I will have opportunities to use the Q8 this weekend and it would be a shame to leave it at home.

[zespectre]

@Zulumoose

If you really are that desperate, buy one high drain button top cell, you can run the Q8 fairly well on one cell, you just won’t see the peak output.

I KEEP forgetting it will do that.
Thanks for the reminder. LOL

[joechina]

No,
please don’t do this.
If you run a Q8 on full power on a single Samsung 30Q it can heat up the spring and it will lose tension and sags.
Somebody in the Q8 thread had done this.

Edit:
It seems it was the Miller with two 30Q on full throttle.

Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

Argh and I just notice you are a BLFer much much longer then me, sorry automatic response with 1 or 2 posts members asking to be put on the list Yeah David you are right. Sigh The S70 springs are nice and thick though Looking for a solution that requires the least redesign My two springs where I emptied 2*2 30Q on turbo on have indeed sagged about half a mm

Djozz too

Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

I found a likely problem with my Q8 when using short batteries like my solder blobbed 30Q's and BD's. I was testing the light output with 1 to 4 batteries, on both types mentioned above, when unexpectedly on 3 BD's the ouput was not better than on 2 BD's. And this is what caused it: [image] The springs are loosing tension which caused one battery not to touch the batt+ contact ring on the driver. This may be caused by the one battery test that causes quite some current through the battery spri…

Haven’t you read the Q8 thread completely?

[ValuseekeR]

That’s good info Joechina, thank you. (No, I haven’t quite made it through all ~17k posts over there yet lol.)

[sb56637]

@joechina

No,
please don’t do this.
If you run a Q8 on full power on a single Samsung 30Q it can heat up the spring and it will lose tension and sags.
Somebody in the Q8 thread had done this.

Edit:
It seems it was the Miller with two 30Q on full throttle.
Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light - #7637 by The_Miller

Djozz too
Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light - #7593 by djozz

Haven’t you read the Q8 thread completely?

Wow, good to know this, thanks!

[joechina]

Yes thats true. The lamps where prototyps. But I don’t know how much better the production springs are.
The principle is the same with one battery you have 4 times the current and a 30Q can deliver this, the spring gets hot and weakens the tension.
I wouldn’t risk it.
But you can use the Q8 and one cell if:

- don’t run it on MAX or

- you use a half empty high drain cell

• when you have bypassed springs you can use MAX on a fresh 30Q

[mikeymikey]

Having hard time finding decent button top batteries for Q8. Most places are out of stock.
Is Banggood or aliexpress reliable to get batteries? Any other US source with good batteries in stock? Leaning towards Samsung or Sony but open to suggestions.

thx

[Lightbringer]

Got a set of 30Q buttons from FT a while back.