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

In height, inner black plastic is definitely lower than the brass. for the outer, boy, I've been fingering the feel (?) for 5 mins and it's hard to tell. That's my pic of this light, and the pic seems deceptive. I'd say the brass is ever so slightly higher accept maybe where the screws are - feels bout even.

I don't have a lot of feel left in these fingers anyways .

This thread is over 7000 posts long, so forgive me if this has been asked.

Does the Q8 still run with anything between 1 and 4 cells? Other than run time, does using less than 4 cells affect maximum brightness? Thanks.

It’s 4 cell in parallel so you can use any number of cells you want.

Maximum brightness, or amp draw, is about 20 amps so 4 cells share that at 5 amps each. The fewer cells you use, the more voltage sag you get and that results in less lumens. Because max lumens is gonna happen at the highest voltage.

I’m sure one or two cells can get close to max brightness, but not all the way max like 4 cells can.

Does that answer your question?

Even though I knew the answer to his question, your reply helped me understand even better, perfect explanation, cheers

Yes, thank you!

A few pictures from the sample light I received.
Firstly when I first inspected the light the most disappointing part I could find was the led alignment. It did not seem to affect the beam pattern at all but non the less they were not perfectly aligned.

When reassembling the light after taking these pictures I was pleasantly surprised that the leds were near on in perfect alignment with the reflector openings. I guess the reflector twisted slightly when the centre screw was tightened

The lens sits on a softish white oring.

The oring itself sat on a shelf with enough of the oring sticking above the reflector that should give a good seal against the glass lens. Saying that I would choose another light to go swimming with.

I loved the way the driver was held in with two screws having seen anough press fit drivers loose there effective press fit after being removed and replaced a few times. Here you can see the kidney shape with the threads that hold the driver in. Just the shape itself would have to add to the strength of the head and add effective heat sinking as well. The retaining screw for the reflector can be seen in here in the middle of the head along with the thickness of the MCPCB shelf. It would have to be around six mm or a 1/4’’ in thickness.

With the reflector removed the MCPCB can be seen along with its two retaining screws. It sits neatly in its own machined space.

The base of the reflector shows the machined hole in the centre for clearance on the positive and negative wires where they solder to the MCPCB. There is no chance of shorts here. The outer machined holes are for clearance on the MCPCB retaining screw heads.

No visible flaws could be seen on the working side of the reflector.

The lens appeared to be plain glass. It was a meaty 3mm in thickness and 55mm in diameter. The oring was 2mm in width.

The worst part of the light I could find was the top edge of the holes for the battery’s in the battery tube. There were no burs as such but the edge was reasonably sharp.

Whats there not to like about this light? In my view nothing really. One thing I should also mention was when I swapped the negative end of the light over for the proto I built with spring bypasses the output rose sufficiently enough that I will mod this light with spring bypasses as well.

With the design of the light the way a light should be and with the trend setting modes on the driver of which Tom seems to have spent every last second and then more putting together and problem solving behind the scenes I would like to publicly say thanks.
It has become my go to light for 90% of my torch needs.
This really is a bargain in todays world of torches and no this is not a paid advertisement. :slight_smile:

So technically any true 20A cell can handle or give out max output albeit at 3/4 less runtime?

Not quite.

Think of it like this. The stock battery on your car will crank the engine over at normal speed because it has minimal voltage drop due to its size.

If you hook a small motorcycle battery to your car it may crank it, but it will spin slower due to the bigger voltage drop when under the same cranking load.

So 4 good cells in the Q8 on turbo (20 amp load) may drop the voltage from 4.2 volt to 4.1 volt.

Now let’s say you put one battery in that is 20 amp capable. Put the light on turbo and you will get a bigger voltage drop. It may drop to 3.5 volt and theoretically still pull 20 amps. The amp draw will actually be lower, but let’s keep it the same for this example.

20 amps at 4.1 volts is 84 watts of output.

20 amps at 3.5 volts is 70 watts of output.

So a single battery may still give you turbo, but it is not the max turbo you’d get from 4 cells.

Now getting back to the amp draw, the FET driver is only going to put out what the battery can deliver. So a single cell under heavy load is going to have lower voltage as well as a lower amp draw. I don’t know how much lower as I’m still learning about FET drivers.

I’m sure some one can step up and measure the current draw with a single battery and tell us how low the voltage actually drops (I’m just guessing 3.5v or so) as well as how many amps it draws. I’m curious about actual numbers myself.

Nice post and analysis MRsDNF!
Agree with you
Pressing down on the glass while tightening the bezel also made my LEDs align better.

Yes it works with less then four cells, lol using a single Panasonic protected cell and it shuts itself off on max. It with 2 GAs no problems there.

I’m sure the protection circuitry is kicking in and shutting the power off.

Will it do turbo on one GA? If the voltage sags too low the LVP may step in.

let me check that right away

! pana, Q8 shuts down and can be turned on right away,but shuts down on turbo
1 GA, Q8 sustains turbo
2 pana, Q8 sustains turbo

So 4 10A GAs will sag lower than 4 30Qs if we are to really look at the difference in a graphing meter but I wonder how much difference to the human eyes…even with one 30q

No, not really. If your comparing 4 cells to 4 cells then you have to remember that each cell is only going to pull about 5 amps. I don’t think there’s going to be much difference in voltage sag at all between these 2 cell types.

I think one type pulled 20 amps and the other 18 amps? I can’t remember the details, but they were pretty close. I think it was a 500 lumen difference? 5500 lumen to 6000 lumen. Your not going to notice that small a difference with your eyes.

Now with a single 30q you’ll have less voltage and less amp draw which will add up to a much bigger lumen drop. You might see the difference with your eyes in this scenario.

Like I said, I hope someone can test this and give us actual numbers instead of theory.

:beer: bro!

Ah and notebook works, so MARK

And for a better overview I started by editing in links to the several posts where the proto 3/samples are shown and talked about so it is easier to find.

:+1: on the working laptop!

Did not do further testing on the proto last night, instead I slept to recover from 8 hours volleyball in the burning sun…

Sleep Djozz? no no, testing :smiley:

I thought this too, but looking inside reflectors with a led in the center the yellow kind of shows all around, this makes me think that there is not a lot of difference in the angle.

heheh no “all funny business on a small stick” of course :slight_smile:

Djozz, an you check lumens with 1 ,2, 3 to add to your 4 cell results?

I noticed with the xhp50.2 it had a slightly square shaped corona. Is this what you guys are talking about, the corona shape?