Im going to make kit for meteor-style mod.

I’m posting to keep me updated on this thread. Thanks for starting it.

As for now, the only modding I’ll do from the get go is comparing GA to VTC6 cells when the lights finally make it to my door.

Looking forward to some high cri 50.2s though. That one has me very interested.

kiriba-ru wrote:

Im going to make kit for meteor-style mod.

How easy (or hard) is to change the 4P setup to 2S2P or 4S setup? Do we need additional pieces or can we mod the existing host with just some soldering skills?

Modding the Q8 to an XHP50.2 might be kinda expensive in comparison to the cost of the flashlight. IDK but a decent driver might already cost half of the price of the Q8. With LEDs and MCPCB it will cost more then the Q8 it self. Don’t get me wrong I would really love a monster flooder, I have more use for it than I have for a thrower. But the the overall cost might be too much for me.

Thank you.

To convert to 4s you would need a new driver, the TA46 multi-cell is already ready for this and I have used it in a few lights. The tailcap can be modded to work or you can order one of the tailcaps I made for this.

The process is not that hard but also not that simple. I would put it at an intermediate to maybe mildly advanced mod. No special tools are needed besides a drill but a bit more work needed then a basic emitter swap.

goshdogit wrote:

kiriba-ru wrote:

Im going to make kit for meteor-style mod.

Please tell us more!

Driver. I dont like primitive direct-drive drivers and I plan to replace it to something more modern

High-cri 219b fans can use existing 46mm linear drivers.

Texas_Ace wrote:

To convert to 4s you would need a new driver, the TA46 multi-cell is already ready for this and I have used it in a few lights. The tailcap can be modded to work or you can order one of the tailcaps I made for this.

The process is not that hard but also not that simple. I would put it at an intermediate to maybe mildly advanced mod. No special tools are needed besides a drill but a bit more work needed then a basic emitter swap.

> hurts a little

I hope not too much. You all creating the C8 have worked up a really good flashlight, that can’t incorporate everything.
It’s also, sounds like, going to be a really excellent platform for people who want to try variations on the design.

I’m from the old school that likes constant-brightness lights rather than ‘hotrod’ direct drive lights because those slowly get dimmer as battery voltage drops,
though I’m aware that shortens the total useful time the light will light up if the user isn’t smart enough to choose lower levels.

I recognize why the direct drivers are currently (heh) popular, and recognize that the “best of both worlds” driver designs are probably too complicated and pricey for manufacturers to use as default choice.

kiriba-ru wrote:

High-cri 219b fans can use existing 46mm linear drivers.

Texas_Ace wrote:

To convert to 4s you would need a new driver, the TA46 multi-cell is already ready for this and I have used it in a few lights. The tailcap can be modded to work or you can order one of the tailcaps I made for this.

The process is not that hard but also not that simple. I would put it at an intermediate to maybe mildly advanced mod. No special tools are needed besides a drill but a bit more work needed then a basic emitter swap.

Are you sure that 4s or 2s2p mod is good idea? Parallel config is more safety and allows cell change to the touch in darkness. I dont think there is any difference between buck and boost driver self-cost.

As time move forward BLF lights will catch up to the big brand lights that run the batteries in series for higher voltage.

The Q8 for example with no other changes except running the cells and LED’s in 4S would be able to use a fairly simple and cheap buck driver that would give constant current, higher efficiency and even higher output is desired. There is a reason the big brands run the cells in series for high powered lights, it is simply the better way of doing things.

kiriba-ru wrote:

goshdogit wrote:

kiriba-ru wrote:

Im going to make kit for meteor-style mod.

Please tell us more!

Hard to say anything special when you dont have host on your hands.

Texas_Ace wrote:

As time move forward BLF lights will catch up to the big brand lights that run the batteries in series for higher voltage.

The Q8 for example with no other changes except running the cells and LED’s in 4S would be able to use a fairly simple and cheap buck driver that would give constant current, higher efficiency and even higher output is desired. There is a reason the big brands run the cells in series for high powered lights, it is simply the better way of doing things.

> cells in series

I recall the observation elsewhere that even if you start with identical, perfectly matched cells, they’ll slowly become different as they’re repeatedly cycled.
Once they differ, even though they can be charged exactly the same when full, they’ll end up at different voltages when they’re drained, so one could get reversed.

Giving people lights with cells in series, you have to add the warning SB phrased so well in an earlier thread about battery charging:

Quote:

… please don’t blow yourself up or burn your house down …

The Q8 design is smart because parallel cells don’t build unbalanced cell risk into the design.

Yeah, it’s got the one-cell-overheat-on-turbo option for people who use it wrong, but nothing’s going to be fool-proof.

try to make the world idiot proof and the world will come up with a better idiot….
Has it been discussed what could happen if one would put different cells at extremely different states of charge in the Q8?

Running cells in series presents virtually no risks with a single discharge cycle such as in a flashlight.

The issue comes when you never remove them from the pack and charge them in series as well. In that case they most assuredly can become unbalanced (although much less then it is made out to be with quality cells). This is a non-issue for flashlights though since we remove them and charge them individually.

The only thing you need to do in the case of series cells is set the cutoff voltage slightly higher then you might otherwise with parallel cells (say a 3v cutoff instead of 2.8v if you really wanted a margin of safety from killing the cells).

Seeing as the big manufactures use almost exclusively cells in series, I am going to say that the benefits far outweigh the possible side effects. There is a reason they run them in series.

There is virtually zero fire hazard with series over parallel cells as long as the cells are installed properly and you can install fuses to prevent the worst case scenario.

The Miller wrote:

Wildcat wrote:

Driver. I dont like primitive direct-drive drivers and I plan to replace it to something more modern

Auch this hurts a little

Why?!

You wanted to make a photoflash in SRK body and you did it! Great job! And now I want to do a good flashlight in this body

Be nice, now. A big Thank You for getting it to where, someday soon, it’ll be available to play with.

I’m hoping those who got the early samples may have already modded them and care to show their work.

DavidEF wrote:

Possibly, he just doesn’t know what you mean by “meteor-style mod” as in the idea itself. Are you talking about a copper or aluminum spacer for TIR triples/quads or something else? I’m assuming the spacer is what you mean, since you’ve done those before.

DavidEF wrote:

kiriba-ru wrote:

I dont think there is any difference between buck and boost driver self-cost.

2S or 4S mod is required for the higher voltage emitters. Agree, there’s no need to change the driver for ~3V LEDs.

Texas_Ace wrote:

As time move forward BLF lights will catch up to the big brand lights that run the batteries in series for higher voltage.

The Q8 for example with no other changes except running the cells and LED’s in 4S would be able to use a fairly simple and cheap buck driver that would give constant current, higher efficiency and even higher output is desired. There is a reason the big brands run the cells in series for high powered lights, it is simply the better way of doing things.

Texas_Ace wrote:

Be warned, these drivers will not be cheap, the parts alone add up to around $20-25 without the PCB. The PCB alone will cost about $15, so expect to pay $35-$40 for one of these drivers fully assembled.

kiriba-ru wrote:

DavidEF wrote:

kiriba-ru wrote:

I dont think there is any difference between buck and boost driver self-cost.

2S or 4S mod is required for the higher voltage emitters. Agree, there’s no need to change the driver for ~3V LEDs.

Please read one more time.
Parallel config is safe and well-known – one rear pcb with thick traces and 4 springs, one thick brass ring soldered to the driver and button top cells.
4S or 2S2P mod require springs from both sides, one contact plate should rotate, other should be fixed, this is not safety decision.

Still, I’d say buck is better for one reason: it doesn’t strain the cells as much as boost, especially for high output. AFAIK, for cell strain, boost is the worst, then direct drive and/or linear, then buck the least.

DavidEF wrote:

Still, I’d say buck is better for one reason: it doesn’t strain the cells as much as boost, especially for high output. AFAIK, for cell strain, boost is the worst, then direct drive and/or linear, then buck the least.

kiriba-ru wrote:

DavidEF wrote:

Still, I’d say buck is better for one reason: it doesn’t strain the cells as much as boost, especially for high output. AFAIK, for cell strain, boost is the worst, then direct drive and/or linear, then buck the least.

How do you all calculate this?
I(in)=E(driver eff.)xI(out)xU(Vf)/U(Vcell)
With same eff., there is no difference.
In real world processes are not so simple and input power is not linear and have some “ripples” but both boost and buck have this effect.
Also, how boost can be worst, if peak current will be always lower than DD with same cells-leds?

As the cells deplete, the difference is even greater, as boost drivers have to convert harder, which works the cell(s) harder, at the same time that the cells themselves are getting weaker. Alternatively, buck drivers are actually working less the lower the input voltage goes. The cells have it easy the whole time, while the buck driver can keep the output to the emitter(s) in perfect regulation longer as well.

Like I said, I may not understand this well enough myself. Texas_Ace makes these statements all the time, though. Perhaps he can step in and explain this difference better than I can.

.
.

EDIT: Just wanted to address this last statement of yours as well.

Quote:

Also, how boost can be worst, if peak current will be always lower than DD with same cells-leds?

DavidEF wrote:

Well, maybe I don’t understand it well enough. But, I’d think that in converting voltage, the max current is also converted in the opposite direction. So, in a boost circuit, the max current to the emitter(s) is necessarily lower than the max current from the cell(s). For a buck circuit, it moves the other way. Since the voltage is being lowered from cell(s) to the emitter(s), the max current available to the emitter(s) is higher than the max from the cell(s). So, for any specific desired current draw at the emitter(s), a boost driver draws more from the cell(s) and a buck driver draws less.

As the cells deplete, the difference is even greater, as boost drivers have to convert harder, which works the cell(s) harder, at the same time that the cells themselves are getting weaker. Alternatively, buck drivers are actually working less the lower the input voltage goes. The cells have it easy the whole time, while the buck driver can keep the output to the emitter(s) in perfect regulation longer as well.