The reason NiMh’s are not often used in (chinese) flashlights is because of the somewhat lower energy density, but mainly their 1.2V nominal voltage requires power-limiting boosting or running at least 4 in series. Our proposed mini-SRK has 4 cells by design idea, so the use of NiMh cells is automatically a consideration.
And then the advantage of NiMh comes in sight: it is safe, well-known to the public, very available, alkalines can be used as back-up. But IMO another main advantage is power capability: good NiMh cells have very low internal resistance and allow high currents just like that. 4 cells in series have enough overhead voltage to deliver a triple or quad well over 10A even when using the relatively higher voltage Cree leds. I have not seen a NiMh-powered triple or quad (anyone know one?), but if well build (especially the battery carrier, there’s many spring connections there, steel springs are not an option) the output must be quite impressive, 2000 lumen should easily be achievable.
I see no one reasonable idea except just Feng Shui design (4 led => 4 cells) why we should stick to 4*14500 or 4*AA instead of 1*26650
26650: cheaper, more capacity, more Amps.
NiCd(NiMn) afair is sensitive to working mode - it should be dis(charged) in full to avoid memory effect. And you can’t use 1-2-3*AA configuration.
PLease let us focus on the Q8 for now,
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. Must restist temptation to jump in MUST RESIST TALING ABOUT THE SMALLER VERSION CAN I? Yes the urge can be controlled I do have self restrain just press save now!
Right now we lean to XPL Hi in two tints for easy of manufacturing. We will ask of the 219C can be a third choice.
We are looking into the new Cree that started a few topics yesterday.
The XHP or MTG2 will be modding projects from you guys who want to.
Do know the integrated shelf, the square threading and overall quality and features should be making this a worthy light for modding.
The same for me.
3*xhp35 would cost almost the same as 4*xp-l hi. It provides more efficiency per Wt and imo more possibilites for modding.
But we need boost driver for 4p cells
Btw what about the beamshots, does hotspot shape look good for 4*led reflectors comparing with 3*led reflectors ?
In the 70CRI 219C sales thread from RMM I did a small output calculation comparing the 219C to a similar tint and CRI XP-L Hi at 5A, and qua output the XP-L Hi wins by a margin.
In a direct drive situation the situation is different and could be as follows:
depending on flashlight resistances and type of battery, because of its very low Vf the 219C will draw more amps than the XP-L Hi, then at the cost of more power and heat the output of the 219C’s could still come close to the output of XP-L Hi’s.
Consideration for 219C could be the lowVf, tint, and price, but it will probably not have the best output and runtime, and it will run the flashlight hotter.
Yes Djozz is right to the point here. We are considering the new Cree but for now the XP-L HI is the winner and aim.
We are aiming at making the Q8 accept the current SRK reflectors.
Meaning one could mod it into a light using anywhere from 3 to 10 emitters.
I am going to BOLD some specs in the OP that are set like the 4 parallel cell configuration and XP footprint for LEDs to avoid confusion and having to repeat the need for modding oneself if XHPs are wanted every page of this thread
80CRI or higher has not been achieved in a group buy, probably because they are difficult to source in China. Intl-outdoor and Mtn-electronics every now and then have limited batches of nice 80CRI leds, but once they sell out the same type does not come back. I have not spotted 80CRI XP-L Hi’s yet, apart from 3000K ones that are 80CRI by default.
Still don’t know that much about different LEDs etc.
But I’m hoping that the heat dissipation will be enough to keep the light on high/turbo for “some time” and not just 30 seconds and then drop to “too low”.
If we manage to achieve a proper direct drive on all 4 leds, the flashlight will get hot fast, but (even relatively) there will be more mass and surface area as a tube-style 18650 light (such as the BLF-A6), so my estimation is that the light can run on turbo a bit longer, say at least two minutes. It is something that has to be determined in the prototypes but this being a BLF-special I’m sure we will not be too shy on that.
I’d definitely be interested in this if it comes with the 219C R8000 D280 like the ones Mountain Electronics sells. I’m less interested if I have to add those myself, but could still talk myself in to it.
LOL, we are a full nine days underway in this group buy, in which a flashlight will be completely or partly new designed. The last two group buys that involved (re)designing flashlights (BLF-A6 and the X6/X5 lights) took more than a year before the lights were finally for sale.
